Association between Hematocrit in the First Two Hours of Life and Retinopathy during Prematurity: A Retrospective Study from DRYAD

Association between Hematocrit in the First Two Hours of Life and Retinopathy during Prematurity: A Retrospective Study from DRYAD | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Association between Hematocrit in the First Two Hours of Life and Retinopathy during Prematurity: A Retrospective Study from DRYAD Xiaohui Kong, Huabin Wang, Ru Yang, Min Zhang, Chengshuai Li, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4141695/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 08 Mar, 2025 Read the published version in BMC Pediatrics → Version 1 posted 14 You are reading this latest preprint version Abstract Introduction: Our study investigated the association between hematocrit in the first two hours (HCT2h) of life and retinopathy of prematurity (ROP). Methods Data were obtained from an observational study of the DRYAD database. The study was conducted at the Santa Clara Valley Medical Center (SCVMC). Data on preterm babies whose gestational age (GA) was < 34 weeks were collected prospectively from January 2008 to February 2014. Logistic regression was applied to explore the association between HCT2h and ROP. Results A total of 326 very preterm infants born at or earlier than 34 weeks were included. The incidence of any ROP was 23.9%, and the incidence of severe ROP was 4.6%. The HCT2h, birth weight, GA, Apgar1 min, and Apgar5 min of any ROP group were significantly lower than those of preterm babies without ROP (p 0.05). We classified HCT2h into three levels, and after multivariate logistic regression, we found that high HCT2h remained a significant protective factor against ROP (p < 0.001). Through subgroup analysis, we observed that among preterm infants with a GA of 28 weeks or more, there was a significant inverse association between a 1% increase in HCT2h and a 17% reduction in the occurrence of ROP. Conclusion We found that a greater HCT2h was associated with a lower incidence of ROP among preterm infants born between 28 and 34 weeks of gestation. Trial registration: This was a retrospective study and the data were from the DRYAD database. Santa Clara Valley Medical Center’s (SCVMC) ethical committee reviewed and approved the studies involving human participants. The participants provided their written informed consent to participate in this study. We did not perform any extra interventions. Hematocrit Retinopathy of prematurity Premature infant Retrospective study Figures Figure 1 Introduction Retinopathy of prematurity (ROP) is a neovascular disorder affecting the immature retina, and because of the lack of effective and efficient screening, it is the primary cause of preventable visual impairment worldwide, especially in developing countries ( 1 ), ( 2 ). Screening at-risk preterm infants following birth in the neonatal intensive care unit (NICU) is imperative for ROP management, as early detection and treatment of severe disease can decrease the risk of blindness. Numerous studies have explored risk factors for ROP to identify a way to screen for ROP early. Several perinatal ( 3 ) and postnatal factors, such as elevated maternal leukocyte count and clinical chorioamnionitis, have been associated with ROP, and the most common and well-studied perinatal and neonatal risk factors for the development of severe ROP are hyperoxemia, hypoxia, and prolonged respiratory support ( 4 ). The current screening criteria for ROP, birth weight (BW) and gestational age (GA), have high sensitivity but low specificity ( 5 ), and others use postnatal weight gain or insulin-like growth factor 1 (IGF-1) levels to screen for ROP. Ana C. Almeida investigated the associations between hyperglycemia, glycated albumin (GlyA), and ROP. The study revealed that hyperglycemia, but not GlyA, was a significant risk factor for ROP, outweighing other recognized risk factors ( 6 ). Some studies have examined the effect of cord blood magnesium levels on ROP and found no relationship ( 7 ). Low platelet counts and serum VEGF-A levels have been found to be associated with ROP development ( 8 ). Moreover, another study showed that oral supplementation with vitamin E and DHA may decrease oxidative damage markers and effectively prevent ROP development in VLBW infants with RDS ( 9 , 10 ). Very early postnatal biomarkers predictive of ROP outcome have not yet been identified. The association between hematocrit in the first two hours of life (HCT2h) and ROP development has not been identified in any previous study. We conducted a secondary data analysis based on open-source data from a previously published paper ( 11 ). The objective of this study was to explore the association between HCT2h and ROP among very preterm infants born at or earlier than 34 weeks. Methods Data Source Detailed citations were used to obtain information on the studies of Song Dongli, Jegatheesan Priya, DeSandre Glenn, and Govindaswami Balaji ( 11 ). All data files are available from the data dryad database (doi: 10.5061/dryad.4q3d3 ). Study population This was a prospective observational study conducted from January 2008 to April 2014 at the Santa Clara Valley Medical Center (SCVMC). The Ethical Review Boards of the SCVMC approved the study. Following the current + screening guidelines, all infants with a GA < 34 weeks who underwent delayed cord clamping (DCC) (30–75 s) and whose hematocrits were < 2 hours were included. Infants without hematocrits within 2 hours of life were excluded. Data collection and measurements The following variables of the enrolled participants in the database were included: GA, BW, sex, Ans [antenatal steroid (any and > 48-hour exposure)], delivery mode, multiple pregnancy status, Apgar status at 1 and 5 minutes, Etippv (delivery room intubation and positive pressure ventilation), Drccompmeds (delivery room chest compression and/or resuscitation medication), Atemp (temperature at NICU admission), surfactant administration, Intub1d (intubation within the first 24 hours of life), any intubation and any transfusion (intubation and red cell transfusion at any time during the NICU stay), and Pkbili (peak bilirubin). Hematocrits included in this analysis were those collected at < 2 hours, and those obtained after blood transfusion were excluded. The neonatal morbidities were as follows: IVH, late-onset sepsis (LOS), NEC, chronic lung disease (CLD), any ROP defined as stage 1–3, and severe ROP defined as > stage 2 or with plus disease or requiring surgery or anti-vascular endothelial growth factor treatment for ROP. Statistical analysis The R software program ( http://www.R-project.org , The R Foundation) and Free Statistics software version 1.9 were used for all the statistical studies. P < 0.05 indicated statistical significance. The distribution of the study participants' baseline values for each of the several HCT2h categories (tertiles) is displayed. Percentages (%) are used to express categorical variables. Normally distributed continuous variables are given as the mean and standard deviation (SD) or, if skewed, as the median and interquartile range (IQR). The categorical variables were compared with regularly distributed and nonnormally distributed continuous variables using Q-way analysis of variance (normal distribution), the Kruskal‒Wallis test (skewed distribution), and the chi‒squared test (categorical variables). This study employed multivariable logistic regression analysis to evaluate the potential independent relationship between HCT2h and the occurrence of ROP. We adjusted for features that altered the adjusted odds ratio (OR) by at least 10% when they were included in this model. The mode of delivery, sex, BW, and GA were all periodically adjusted. The assessment of collinearity was performed before multivariate analyses. Following the guidelines in the statement "Strengthening the Reporting of Observational Studies in Epidemiology," HCT2h was examined as a continuous variable in each of the modified models [2]. At the same time, we displayed the outcomes of the following analyses: unadjusted, minimally adjusted (BW, GA, sex, delivery mode), multiply adjusted (BW, GA, sex, delivery mode, Multiple Pregnancy, Ans, Apgar1, Apgar5), and fully adjusted (BW, GA, sex, delivery mode, Multiple Pregnancy, Ans, Apgar1, Apgar5, Etippv, Drccompmeds, Atemp, Surfactant, Pneumothorax, Intub1d, Anytransfusion, Pkbili). Stratified regression models were used for subgroup analysis. Likelihood ratio tests were used to examine the changes and interactions among subgroups. Results Baseline characteristics The DRYAD data of 352 extremely preterm babies were retrieved. A total of 326 preterm individuals whose hematocrits were collected within the first two hours of life were analyzed, and 26 preterm patients without HCT2h data were removed from the analysis. Of the 326 infants, 78 (23.9%) had ROP. The baseline characteristics of the selected participants according to tertiles of HCT2h are shown in Table 2 . The mean BW and GA were 1375.5 ± 461.4 g and 29.6 ± 2.6 w, respectively, and there were 122 males (37.4%) and 204 females (62.6%). A total of 265 (81.3%) singleton pregnancies and 61 (18.7%) multiple pregnancies were recorded. Only nine (2.8%) preterm newborns did not receive glucocorticoids prior to delivery, out of the 317 (97.2%) who received prenatal steroids. Of the deliveries, 196 were by cesarean section (60%), and 130 were by normal delivery (39.9%). The Apgar score at one minute was 5.9 ± 2.3, and at five minutes, it was 7.5 ± 1.7. Ninety-six percent of patients received resuscitation medicine and/or chest compression in the delivery room, while 82.5% received intubation and positive pressure ventilation. Her temperature at admission was 36.9 ± 0.5°C. Among the preterm newborns, 260 (79.8%) received lung surfactant, whereas 66 (20.2%) did not. Within 24 hours of birth, 91 (27.9%) preterm infants were extubated, while 111 (34%) accepted intubation while they were in the NICU. Pneumothorax occurred in eleven (3.4%) preterm neonates, and 92 (28.2%) received blood transfusions. All of these preterm babies had a peak bilirubin concentration of 8.4 ± 2.6 mg/dL. Univariate and multivariate analyses of HCT2h and ROP The results of the univariate logistic regression model analyses are shown in Table 3 . Risk factors for ROP are Etippv, positive pressure ventilation by endotracheal intubation in the delivery room, Drccompmeds, delivery room chest compression and/or resuscitation medication, surfactant, pneumothorax, intubation within 24 hours of life, and intubation any time during the NICU stay. The protective factors included gestational age, 1-minute Apgar score, 5-minute Apgar score, admission temperature in Celsius, peak bilirubin, HCT2h, and vaginal delivery. Table 4 displays multivariate logistic regression models. HCT2h was negatively linked with the incidence of ROP in all models, including the completely adjusted model (adjusted for all the covariates as listed in Table 1 ) and the nonadjusted, minimally adjusted, multiply adjusted, and fully adjusted models. One increase in HCT2h was linked, after multiple correction, to a 9% reduction in the incidence of ROP [OR = 0.91; 95% confidence interval (CI): 0.84,0.97; p = 0.008; Table 3 ]. For the sensitivity analysis, we also considered HCT2h as a categorical variable (tertile), and we found a similar tendency ( p value for the trend was 0.004; Table 3 ). Subgroup Analyses by Adjusted Potential Effect Confounders Table 5 and Fig. 1 show that the interactions for BW, sex, and delivery mode in the subgroup analysis were not statistically significant. In the subgroups, we found that GA interacted with HCT2 ( p < 0.05). Table 1 Comparison of clinical parameters between the no ROP and ROP groups. Variables Total (n = 326) No ROP (n = 248) Any ROP (n = 78) p -value HCT2(%) 48.3 ± 7.0 49.9 ± 6.5 43.1 ± 6.0 < 0.001 BW (g) 1375.5 ± 461.4 1510.7 ± 418.9 945.8 ± 299.8 < 0.001 GA(w) 29.6 ± 2.6 30.4 ± 2.1 27.0 ± 2.0 < 0.001 Sex 0.627 female 122 (37.4) 91 (36.7) 31 (39.7) male 204 (62.6) 157 (63.3) 47 (60.3) Multiples 0.595 No 265 (81.3) 200 (80.6) 65 (83.3) Yes 61 (18.7) 48 (19.4) 13 (16.7) Delivery Mode 0.176 Cesarean section 196 (60.1) 144 (58.1) 52 (66.7) Vaginal delivery 130 (39.9) 104 (41.9) 26 (33.3) Apgar1 5.9 ± 2.3 6.2 ± 2.2 5.0 ± 2.4 < 0.001 Apgar5 7.5 ± 1.7 7.8 ± 1.6 6.7 ± 1.8 < 0.001 HCT2, hematocrit in the first two hours of life; BW, birth weight; GA, gestational age; Multiple, multiple pregnancy; Apgar1,1-minute Apgar; Apgar5,5-minute Apgar. Table 2 Clinical characteristics of the study population according to HCT2 (hematocrit in the first two hours of life). Variables Total (n = 326) Q1 (n = 108) Q2 (n = 109) Q3 (n = 109) p -value BW(g) 1375.5 ± 461.4 1141.0 ± 434.8 1397.7 ± 471.0 1585.7 ± 362.6 < 0.001 GA(w) 29.6 ± 2.6 28.0 ± 2.6 29.7 ± 2.4 31.1 ± 1.6 < 0.001 Sex 0.254 female 122 (37.4) 47 (43.5) 36 (33) 39 (35.8) male 204 (62.6) 61 (56.5) 73 (67) 70 (64.2) Multiple Pregnancy 0.881 No 265 (81.3) 89 (82.4) 89 (81.7) 87 (79.8) Yes 61 (18.7) 19 (17.6) 20 (18.3) 22 (20.2) Ans 1 No 9 (2.8) 3 (2.8) 3 (2.8) 3 (2.8) Yes 317 (97.2) 105 (97.2) 106 (97.2) 106 (97.2) Delivery Mode 0.413 Cesarean section 196 (60.1) 68 (63) 60 (55) 68 (62.4) Vaginal delivery 130 (39.9) 40 (37) 49 (45) 41 (37.6) Apgar1 5.9 ± 2.3 5.0 ± 2.3 6.1 ± 2.2 6.7 ± 1.9 < 0.001 Apgar5 7.5 ± 1.7 7.0 ± 1.7 7.5 ± 1.9 8.1 ± 1.4 < 0.001 Etippv < 0.001 No 269 (82.5) 67 (62) 97 (89) 105 (96.3) Yes 57 (17.5) 41 (38) 12 ( 11 ) 4 (3.7) Drccompmeds 0.045 No 313 (96.0) 100 (92.6) 105 (96.3) 108 (99.1) Yes 13 (4.0) 8 (7.4) 4 (3.7) 1 (0.9) Atemp(℃) 36.9 ± 0.5 37.0 ± 0.5 36.9 ± 0.6 36.9 ± 0.4 0.348 Surfactant < 0.001 No 260 (79.8) 65 (60.2) 92 (84.4) 103 (94.5) Yes 66 (20.2) 43 (39.8) 17 (15.6) 6 (5.5) Intub1d < 0.001 No 235 (72.1) 51 (47.2) 86 (78.9) 98 (89.9) Yes 91 (27.9) 57 (52.8) 23 (21.1) 11 (10.1) Pneumothorax 0.224 No 315 (96.6) 103 (95.4) 104 (95.4) 108 (99.1) Yes 11 (3.4) 5 (4.6) 5 (4.6) 1 (0.9) Any intub < 0.001 No 215 (66.0) 43 (39.8) 77 (70.6) 95 (87.2) Yes 111 (34.0) 65 (60.2) 32 (29.4) 14 (12.8) Any transfusion < 0.001 No 234 (71.8) 48 (44.4) 82 (75.2) 104 (95.4) Yes 92 (28.2) 60 (55.6) 27 (24.8) 5 (4.6) Pkbili(mg/dl) 8.4 ± 2.6 7.1 ± 2.5 8.6 ± 2.6 9.6 ± 2.1 < 0.001 Anyrop < 0.001 No 248 (76.1) 58 (53.7) 87 (79.8) 103 (94.5) Yes 78 (23.9) 50 (46.3) 22 (20.2) 6 (5.5) The data are presented as the means ± SDs or numbers (proportions) for categorical variables. BW, birth weight; GA, gestational age; Ans, antenatal steroids; Apgar1,1-minute Apgar; Apgar5,5-minute Apgar; Etippv, delivery room intubation and positive pressure ventilation; Drccompmeds, delivery room chest compression and/or resuscitation medication; Atemp, admission temperature in Celsius; Intub1d, intubation within 24 hours of life; Any Intub, intubation any time during the NICU stay; Any transfusion, any pRBC transfusion during the NICU stay; Pkbili, peak bilirubin; Anyrop, retinopathy of prematurity (stage 1–3); Q1, Q2, and Q3 are quartiles of the HCT2 (hematocrit in the first two hours of life). Table 3 Univariate logistic regression models evaluating the association between HCT2 (hematocrit in the first two hours of life) and retinopathy of prematurity. Variable OR_95CI p _value BW 1 (0.99 ~ 1) < 0.001 GA 0.47 (0.39 ~ 0.55) < 0.001 Sex2 0.88 (0.52 ~ 1.49) 0.637 Multiple Pregnancy 0.77 (0.39 ~ 1.52) 0.459 Ans 1 0.24 (0.05 ~ 1.1) 0.066 Apgar1 0.73 (0.65 ~ 0.83) < 0.001 Apgar5 0.64 (0.54 ~ 0.75) < 0.001 Etippv 9.12 (4.56 ~ 18.27) < 0.001 Drccompmeds 4.79 (1.32 ~ 17.45) 0.018 Atemp 0.85 (0.51 ~ 1.39) 0.512 Surfactant 6.76 (3.65 ~ 12.51) < 0.001 Pneumothorax 9.67 (1.91 ~ 48.95) 0.006 Intub1d 6.99 (3.94 ~ 12.39) < 0.001 Anyintub 9.15 (5.14 ~ 16.31) < 0.001 Any transfusion 14.99 (8.11 ~ 27.7) < 0.001 Pkbili 0.56 (0.48 ~ 0.65) < 0.001 HCT2 0.83 (0.79 ~ 0.88) < 0.001 Vaginal delivery 0.68 (0.4 ~ 1.17) 0.163 Hypothermia1 1.13 (0.29 ~ 4.37) 0.859 BW, birth weight; GA, gestational age; Ans, antenatal steroids; Apgar1,1-minute Ap Drccompmeds, delivery room chest compression and/or resuscitation medication gar; Apgar5,5-minute Apgar; Etippv, delivery room intubation and positive pressure ventilation; Drccompmeds, delivery room chest compression and/or resuscitation medication; Atemp, admission temperature in Celsius; Intub1d, intubation within 24 hours of life; Any Intub, intubation any time during the NICU stay; Any transfusion, any pRBC transfusion during the NICU stay; Pkbili, peak bilirubin. Table 4 Multivariable-adjusted ORs and 95% CIs of the HCT2 index quartiles associated with retinopathy of prematurity Variable Unadjusted Model1 Model2 Model3 OR(95%CI) p value OR(95%CI) p value OR(95%CI) p value OR(95%CI) p value HCT2 0.83 (0.79 ~ 0.88) < 0.001 0.91 (0.86 ~ 0.97) 0.004 0.9 (0.84 ~ 0.96) 0.003 0.91 (0.84 ~ 0.97) 0.008 HCT tertiles Q1 Ref Ref Ref Ref Q2 0.27 (0.14 ~ 0.49) < 0.001 0.45 (0.2 ~ 1.03) 0.057 0.47 (0.2 ~ 1.09) 0.08 0.46 (0.18 ~ 1.15) 0.096 Q3 0.06 (0.02 ~ 0.15) < 0.001 0.22 (0.08 ~ 0.66) 0.007 0.2 (0.07 ~ 0.63) 0.006 0.23 (0.07 ~ 0.78) 0.018 p for trend 0.25 (0.17 ~ 0.37) < 0.001 0.47 (0.28 ~ 0.79) 0.004 0.46 (0.27 ~ 0.78) 0.004 0.48 (0.27 ~ 0.86) 0.013 Model 1 adjusts for BW, GA, sex, and delivery mode Model 2 was adjusted for Model 1 + Multiple Pregnancy + Ans + Apgar1 + Apgar5 Model 3 is adjusted for Model 1 + Model 2 + Etippv + Drccompmeds + Atemp + Surfactant + Pneumothorax + Intub1d + Anytransfusion + Pkbili Ref, reference; HCT2, hematocrit in the first two hours of life; BW, birth weight; GA, gestational age; Ans, antenatal steroids; Apgar1,1-minute Apgar; Apgar5,5-minute Apgar; Etippv, delivery room intubation and positive pressure ventilation; Drccompmeds, delivery room chest compression and/or resuscitation medication; Atemp, admission temperature in Celsius; Intub1d, intubation within 24 hours of life; Any Intub, intubation any time during the NICU stay; Any transfusion, any pRBC transfusion during the NICU stay; Pkbili, peak bilirubin. Q1, Q2 and Q3 are quartiles of HCT2 (hematocrit in the first 2 hours of life). Table 5 Subgroup analyses of HCT2 and ROP patients. Subgroup Variable n.total n.event_% crude.OR_95CI crude.P_value adj.OR_95CI adj. p _value p .for.interaction GA(w) <28 HCT2 92 53 (57.6) 0.95 (0.88 ~ 1.03) 0.188 1.01 (0.9 ~ 1.14) 0.819 0.024 ≥ 28 HCT2 234 25 (10.7) 0.81 (0.75 ~ 0.88) < 0.001 0.85 (0.76 ~ 0.96) 0.006 BW(g) <1000 HCT2 81 50 (61.7) 0.93 (0.85 ~ 1.02) 0.124 0.99 (0.84 ~ 1.16) 0.892 0.073 ≥ 1000,<1500 HCT2 112 24 (21.4) 0.87 (0.8 ~ 0.95) 0.001 0.85 (0.73 ~ 0.97) 0.02 ≥ 1500 HCT2 133 4 ( 3 ) 0.78 (0.66 ~ 0.93) 0.006 0 (0 ~ 0) < 0.001 Sex female HCT2 122 31 (25.4) 0.84 (0.77 ~ 0.91) < 0.001 0.91 (0.81 ~ 1.02) 0.114 0.733 male HCT2 204 47 ( 23 ) 0.83 (0.77 ~ 0.89) < 0.001 0.95 (0.86 ~ 1.05) 0.283 Delivery Mode Cesarean section HCT2 196 52 (26.5) 0.85 (0.8 ~ 0.9) < 0.001 0.98 (0.9 ~ 1.08) 0.718 0.563 Vaginal delivery HCT2 130 26 ( 20 ) 0.8 (0.72 ~ 0.88) < 0.001 0.84 (0.73 ~ 0.97) 0.018 Discussion The development of ROP is mainly attributed to prematurity and oxygen delivery. Although the pathophysiology of ROP has been widely investigated, it remains somewhat unknown. There are apparently common risk factors, such as low GA and low BW. The univariate logistic regression models of our study indicated that BW, GA, Apgar1, Apgre5, delivery room intubation and positive pressure ventilation, delivery room chest compressions and/or resuscitation medications, surfactant, pneumothorax, intubation within 24 hours of life, intubation any time during the NICU stay, any pRBC transfusion during the NICU stay, and peak bilirubin were all risk factors for ROP development. Our data also showed that premature infants with ROP had significantly lower GA and BW and lower Apgar1 and Apgar5 than non-ROP infants, which was consistent with the findings of previous studies ( 12 ). Determining a possible biomarker of ROP progression in humans is challenging. In recent years, several authors have investigated the possible relationships between routinely tested blood parameters and ROP development, such as a reduced platelet count, and thrombocytopenia has been correlated with severe ROP outcomes ( 13 ). Our study explored the correlation between the incidence of ROP and HCT2h in extremely preterm infants born before or at 34 weeks of pregnancy. In our study, HCT2h was the earliest blood test parameter that can avoid confounding factors, such as systemic treatment, and is easy to obtain. The incidence of ROP and HCT2h were negatively correlated according to the multiple adjustment model. There was an approximately linear correlation between HCT2h and the incidence of ROP when we looked at HCT2h as a categorical variable. This may be related to the decrease in the oxygen-carrying capacity of the blood caused by low HCT and low hemoglobin( 14 , 15 ). The results suggest that including early HCT among routinely measured blood parameters may help to identify preterm infants with GA at 28–34 weeks who may be more prone to ROP well in advance. In this way, we can screen preterm infants at high risk of ROP as early as possible and provide active treatment, thereby reducing the incidence of ROP. The aforementioned statement provides us with novel concepts for the early detection of ROP and for mitigating the risk of ROP through proactive intervention. However, does that mean that if the HCT2 of preterm babies is low, we should administer a blood transfusion. A multicenter randomized trial showed that umbilical cord red blood cell (RBC) transfusion may reduce the severity of ROP in neonates of extreme gestational age ( 16 ). Moreover, another prospective study compared liberal and restrictive RBC transfusions and demonstrated that no statistically significant differences were observed in ROP incidence between these two groups ( 17 , 18 ). However, another study has shown that multiple transfusions of RBCs and PLTs are associated with a higher stage of ROP development. ( 19 ). Previous studies have investigated the potential impact of erythropoietin (EPO) supplementation, iron, or blood transfusions on the development of ROP ( 20 – 22 ), but the results have been inconsistent. Repeated transfusions in preterm infants with anemia of prematurity to replace fetal hemoglobin (HbF) with adult hemoglobin (HbA) are associated with a greater incidence of ROP ( 23 , 24 ). Umbilical cord blood (UCB) contains growth factors and progenitor cells that may affect ROP. Autologous UCB transfusions could reduce the risks associated with heterologous blood products and offer benefits by maintaining physiological HbF levels and potentially XXXimproving postnatal development ( 25 ). DDD may be safer or placental transfusion may be performed for preterm babies with a GA between 28 and 32 weeks. However, for extremely preterm infants younger than 28 weeks, delayed cord clamping (DCC) or UCB infusion cannot reduce the incidence of ROP, which may be related to the extremely immature development of these preterm infants. The role of HCT2 in ROP is not completely understood. The correlation between low HCT2 and ROP development suggests that blood tests after birth may be predictive of an unfavorable course of ROP and may help to elucidate the pathophysiology of ROP. Early identification of 'at-risk' preterm babies through a simple blood test would also help to identify those babies who are more likely to develop ROP and who need to be monitored more closely, ideally improving the management of this potentially blinding condition. Future multicenter, prospective clinical studies and basic research are required to determine the deeper relationship between low HCT2 and ROP and whether preterm infants with low HCT should receive active transfusion. There were certain limitations to this study as well. First, the small sample size of 326 extremely preterm newborns in this study warrants larger sample sizes in future multicenter studies. Second, this study included only American patients. HCT2h is not frequently evaluated in extremely preterm infants in China. When extrapolating the findings of this study to other populations, caution should be exercised. Third, some eligible patients may have been removed from the initial study because this was a secondary analysis of data from a previously published study. Conclusions ROP and HCT2h had a negative correlation. A reduced incidence of ROP was linked to a greater level of HCT2h in very preterm infants born at or before 34 weeks of gestation. Further research on this correlation is warranted. Declarations Ethics approval and consent to participate The Santa Clara Valley Medical Center’s (SCVMC) ethical committee reviewed and approved the studies involving human participants. The participants provided written informed consent to participate in this study. Consent for publication Not applicable. Availability of data and materials The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author. Competing interests The authors declare no competing interests. Funding This study was supported by the Key Research and Development Plan of Jining City funded by the Jining Science and Technology Bureau (2023YXNS160 and 2023YXNS112), the Cultivation Plan of High-Level Scientific Research Projects at Jining Medical University (JYGC2021FKJ010) and the "Miaopu" Scientific Research Program of the Affiliated Hospital of Jining Medical University (MP-MS-2021-014). Authors’ contributions Kong Xiaohui designed the study. Yang Ru, Zhang Min, Li Chengshuai, Zhang Rui a , Wei Lihua, and Xu Jing collected and analyzed the data. Kong Xiaohui wrote the first draft of the manuscript. Wang Huabin interpreted the results. Ren Xueyun contributed to the refinement of the manuscript. The final manuscript has been read and approved by the authors. Acknowledgments We thank Song Dongli (Santa Clara Valley Medical Center) for providing the original data. Authors’ information(optional) Not applicable. 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Effect of Enteral Lipid Supplement on Severe Retinopathy of Prematurity: A Randomized Clinical Trial. JAMA Pediatr. 2021;175(4):359–67. Song D, Jegatheesan P, DeSandre G, Govindaswami B. Duration of Cord Clamping and Neonatal Outcomes in Very Preterm Infants. PLoS ONE. 2015;10(9):e0138829. Carranza-Mendizabal CS, Diaz-Manrique M, Ruiz Mamani PG, White M, Huancahuire-Vega S. Incidence and Risk Factors Associated with Retinopathy of Prematurity in Peru. Clin Ophthalmol. 2021;15:2141–8. Parrozzani R, Nacci EB, Bini S, Marchione G, Salvadori S, Nardo D et al. Severe retinopathy of prematurity is associated with early post-natal low platelet count. Sci Rep. 2021;11(1). Gantz MG, Carlo WA, Finer NN, Rich W, Faix RG, Yoder BA, et al. Achieved oxygen saturations and retinopathy of prematurity in extreme preterms. Arch Dis Child Fetal Neonatal Ed. 2020;105(2):138–44. Tandon M, Ranjan R, Muralidharan U, Kannan A. Influence of Anaemia on Multifactorial Disease Retinopathy of Prematurity: A Prospective Observational Study. Cureus. 2022. Teofili L, Papacci P, Orlando N, Bianchi M, Pasciuto T, Mozzetta I, et al. BORN study: a multicenter randomized trial investigating cord blood red blood cell transfusions to reduce the severity of retinopathy of prematurity in extremely low gestational age neonates. Trials. 2022;23(1):1010. Lee EY, Kim SS, Park GY, Lee SH. Effect of red blood cell transfusion on short-term outcomes in very low birth weight infants. Clin Experimental Pediatr. 2020;63(2):56–62. Knee D, Knoop S, Davis AT, Rawson B, DiCarlo A, Olivero R. Outcomes after implementing restrictive blood transfusion criteria in extremely premature infants. J Perinatol. 2019;39(8):1089–97. Hengartner T, Adams M, Pfister RE, Snyers D, McDougall J, Waldvogel S, et al. Associations between Red Blood Cell and Platelet Transfusions and Retinopathy of Prematurity. Neonatology. 2020;117(5):562–8. Fauchere JC, Koller BM, Tschopp A, Dame C, Ruegger C, Bucher HU, et al. Safety of Early High-Dose Recombinant Erythropoietin for Neuroprotection in Very Preterm Infants. J Pediatr. 2015;167(1):52–7. e1-3. Dani C, Bertini MFRG, Martelli E, Pezzati M, Rubaltelli FF. The role of blood transfusions and iron intake on retinopathy of prematurity. Early Hum Dev. 2001;62(2001):57–63. Aher SM, Ohlsson A. Early versus late erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants. Cochrane Database Syst Reviews. 2020;2020:2. Pellegrino C, Papacci P, Beccia F, Serrao F, Cantone GV, Cannetti G et al. Differences in Cerebral Tissue Oxygenation in Preterm Neonates Receiving Adult or Cord Blood Red Blood Cell Transfusions. JAMA Netw Open. 2023;6(11). Glaser K, Härtel C, Dammann O, Herting E, Andres O, Speer CP, et al. Erythrocyte transfusions are associated with retinopathy of prematurity in extremely low gestational age newborns. Acta Paediatr. 2023;112(12):2507–15. Torrejon-Rodriguez L, Pinilla-Gonzalez A, Lara Cantón I, Albiach-Delgado A, Cascant-Vilaplana MM, Cernada M et al. Effect of autologous umbilical cord blood transfusion in the development of retinopathy of prematurity: randomized clinical trial – study protocol. Front Pead. 2023;11. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 08 Mar, 2025 Read the published version in BMC Pediatrics → Version 1 posted Editorial decision: Revision requested 09 Oct, 2024 Reviews received at journal 10 Sep, 2024 Reviewers agreed at journal 20 Aug, 2024 Reviews received at journal 25 Jul, 2024 Reviewers agreed at journal 25 Jul, 2024 Reviews received at journal 21 Jul, 2024 Reviewers agreed at journal 18 Jul, 2024 Reviewers agreed at journal 18 Jul, 2024 Reviewers agreed at journal 14 Jul, 2024 Reviewers invited by journal 05 Jul, 2024 Editor assigned by journal 18 Jun, 2024 Editor invited by journal 26 Mar, 2024 Submission checks completed at journal 26 Mar, 2024 First submitted to journal 21 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4141695","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":284204388,"identity":"7863c3f3-1563-4f54-b4c9-4d329578d09d","order_by":0,"name":"Xiaohui Kong","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xiaohui","middleName":"","lastName":"Kong","suffix":""},{"id":284204389,"identity":"f89a4356-a339-4275-8b14-f9b982c46a47","order_by":1,"name":"Huabin Wang","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Huabin","middleName":"","lastName":"Wang","suffix":""},{"id":284204390,"identity":"62d146ed-dc3f-462d-aa38-ab404c583d5e","order_by":2,"name":"Ru Yang","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Ru","middleName":"","lastName":"Yang","suffix":""},{"id":284204391,"identity":"09fe0b98-9360-44ec-8b55-4b5718889e30","order_by":3,"name":"Min Zhang","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Min","middleName":"","lastName":"Zhang","suffix":""},{"id":284204392,"identity":"eac282c4-5544-4b80-9f72-02b66a18d986","order_by":4,"name":"Chengshuai Li","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Chengshuai","middleName":"","lastName":"Li","suffix":""},{"id":284204393,"identity":"91d8d25d-1be3-4db4-9fc3-f6f146d3b6db","order_by":5,"name":"Rui Zhang","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Rui","middleName":"","lastName":"Zhang","suffix":""},{"id":284204394,"identity":"9d23b863-c3c1-4802-b187-a988346cf628","order_by":6,"name":"Lihua Wei","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Lihua","middleName":"","lastName":"Wei","suffix":""},{"id":284204395,"identity":"d252003c-1b5e-4631-bf8c-cac55f553f19","order_by":7,"name":"Jing Xu","email":"","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Xu","suffix":""},{"id":284204396,"identity":"eb2debd9-71b2-4610-b6f7-2572da1bbbb7","order_by":8,"name":"Ren Xueyun","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7ElEQVRIiWNgGAWjYFAD9saGAx8qJOTkidfCc/jgwxlnLIwNG4jWIpGWbMzZVpHIcICAQvP23mPSPBWHE7cz5JhJM86TSGBsYH746AYeLTJnziUb85w5nLiz4YyZdOE2iTx2BjZj4xx8zpHIMXzM23Y4ccPBHjPpmdskihkbeNik8WqRf2NwmPcfUMthHjNp3jkSiQ0HCGmR4AHa0gDUcowt2Zi3gRgtPDnGhnOOpRtvOMMMDORjEsaGzYT8wn7GTOJNjbXshvsPgVFZUycnz9788DE+LVDQjMRmJqwcBOqIUzYKRsEoGAUjEwAAeTxN2tN0vSkAAAAASUVORK5CYII=","orcid":"","institution":"The Affiliated Hospital of Jining Medical University","correspondingAuthor":true,"prefix":"","firstName":"Ren","middleName":"","lastName":"Xueyun","suffix":""}],"badges":[],"createdAt":"2024-03-21 07:54:42","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4141695/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4141695/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12887-025-05533-8","type":"published","date":"2025-03-08T15:58:41+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":53757541,"identity":"1fbbf749-7219-4a30-b42c-485ba9dfebf9","added_by":"auto","created_at":"2024-03-29 19:08:21","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":28980,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot of the association between HCT2 and any ROP.\u003c/p\u003e","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-4141695/v1/e5288ee8b575b6f91535ad79.png"},{"id":78190801,"identity":"d041624a-b3f0-4f61-b789-2d02d5b97c4a","added_by":"auto","created_at":"2025-03-10 19:50:59","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1096069,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4141695/v1/a0172d11-e320-4cda-849c-61f3f6ac447f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Association between Hematocrit in the First Two Hours of Life and Retinopathy during Prematurity: A Retrospective Study from DRYAD","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRetinopathy of prematurity (ROP) is a neovascular disorder affecting the immature retina, and because of the lack of effective and efficient screening, it is the primary cause of preventable visual impairment worldwide, especially in developing countries (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e), (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Screening at-risk preterm infants following birth in the neonatal intensive care unit (NICU) is imperative for ROP management, as early detection and treatment of severe disease can decrease the risk of blindness.\u003c/p\u003e \u003cp\u003eNumerous studies have explored risk factors for ROP to identify a way to screen for ROP early. Several perinatal (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) and postnatal factors, such as elevated maternal leukocyte count and clinical chorioamnionitis, have been associated with ROP, and the most common and well-studied perinatal and neonatal risk factors for the development of severe ROP are hyperoxemia, hypoxia, and prolonged respiratory support (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). The current screening criteria for ROP, birth weight (BW) and gestational age (GA), have high sensitivity but low specificity (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e), and others use postnatal weight gain or insulin-like growth factor 1 (IGF-1) levels to screen for ROP. Ana C. Almeida investigated the associations between hyperglycemia, glycated albumin (GlyA), and ROP. The study revealed that hyperglycemia, but not GlyA, was a significant risk factor for ROP, outweighing other recognized risk factors (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Some studies have examined the effect of cord blood magnesium levels on ROP and found no relationship (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Low platelet counts and serum VEGF-A levels have been found to be associated with ROP development (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Moreover, another study showed that oral supplementation with vitamin E and DHA may decrease oxidative damage markers and effectively prevent ROP development in VLBW infants with RDS (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Very early postnatal biomarkers predictive of ROP outcome have not yet been identified.\u003c/p\u003e \u003cp\u003eThe association between hematocrit in the first two hours of life (HCT2h) and ROP development has not been identified in any previous study. We conducted a secondary data analysis based on open-source data from a previously published paper (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). The objective of this study was to explore the association between HCT2h and ROP among very preterm infants born at or earlier than 34 weeks.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eData Source\u003c/h2\u003e \u003cp\u003eDetailed citations were used to obtain information on the studies of Song Dongli, Jegatheesan Priya, DeSandre Glenn, and Govindaswami Balaji (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). All data files are available from the data dryad database (doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.5061/dryad.4q3d3\u003c/span\u003e\u003cspan address=\"10.5061/dryad.4q3d3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003eThis was a prospective observational study conducted from January 2008 to April 2014 at the Santa Clara Valley Medical Center (SCVMC). The Ethical Review Boards of the SCVMC approved the study.\u003c/p\u003e \u003cp\u003eFollowing the current\u0026thinsp;+\u0026thinsp;screening guidelines, all infants with a GA\u0026thinsp;\u0026lt;\u0026thinsp;34 weeks who underwent delayed cord clamping (DCC) (30\u0026ndash;75 s) and whose hematocrits were \u0026lt;\u0026thinsp;2 hours were included. Infants without hematocrits within 2 hours of life were excluded.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eData collection and measurements\u003c/h2\u003e \u003cp\u003eThe following variables of the enrolled participants in the database were included: GA, BW, sex, Ans [antenatal steroid (any and \u0026gt;\u0026thinsp;48-hour exposure)], delivery mode, multiple pregnancy status, Apgar status at 1 and 5 minutes, Etippv (delivery room intubation and positive pressure ventilation), Drccompmeds (delivery room chest compression and/or resuscitation medication), Atemp (temperature at NICU admission), surfactant administration, Intub1d (intubation within the first 24 hours of life), any intubation and any transfusion (intubation and red cell transfusion at any time during the NICU stay), and Pkbili (peak bilirubin). Hematocrits included in this analysis were those collected at \u0026lt;\u0026thinsp;2 hours, and those obtained after blood transfusion were excluded. The neonatal morbidities were as follows: IVH, late-onset sepsis (LOS), NEC, chronic lung disease (CLD), any ROP defined as stage 1\u0026ndash;3, and severe ROP defined as \u0026gt;\u0026thinsp;stage 2 or with plus disease or requiring surgery or anti-vascular endothelial growth factor treatment for ROP.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe R software program (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.R-project.org\u003c/span\u003e\u003cspan address=\"http://www.R-project.org\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e, The R Foundation) and Free Statistics software version 1.9 were used for all the statistical studies. P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 indicated statistical significance. The distribution of the study participants' baseline values for each of the several HCT2h categories (tertiles) is displayed. Percentages (%) are used to express categorical variables. Normally distributed continuous variables are given as the mean and standard deviation (SD) or, if skewed, as the median and interquartile range (IQR). The categorical variables were compared with regularly distributed and nonnormally distributed continuous variables using Q-way analysis of variance (normal distribution), the Kruskal‒Wallis test (skewed distribution), and the chi‒squared test (categorical variables).\u003c/p\u003e \u003cp\u003eThis study employed multivariable logistic regression analysis to evaluate the potential independent relationship between HCT2h and the occurrence of ROP. We adjusted for features that altered the adjusted odds ratio (OR) by at least 10% when they were included in this model. The mode of delivery, sex, BW, and GA were all periodically adjusted. The assessment of collinearity was performed before multivariate analyses. Following the guidelines in the statement \"Strengthening the Reporting of Observational Studies in Epidemiology,\" HCT2h was examined as a continuous variable in each of the modified models [2]. At the same time, we displayed the outcomes of the following analyses: unadjusted, minimally adjusted (BW, GA, sex, delivery mode), multiply adjusted (BW, GA, sex, delivery mode, Multiple Pregnancy, Ans, Apgar1, Apgar5), and fully adjusted (BW, GA, sex, delivery mode, Multiple Pregnancy, Ans, Apgar1, Apgar5, Etippv, Drccompmeds, Atemp, Surfactant, Pneumothorax, Intub1d, Anytransfusion, Pkbili).\u003c/p\u003e \u003cp\u003eStratified regression models were used for subgroup analysis. Likelihood ratio tests were used to examine the changes and interactions among subgroups.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eBaseline characteristics\u003c/h2\u003e \u003cp\u003eThe DRYAD data of 352 extremely preterm babies were retrieved. A total of 326 preterm individuals whose hematocrits were collected within the first two hours of life were analyzed, and 26 preterm patients without HCT2h data were removed from the analysis. Of the 326 infants, 78 (23.9%) had ROP. The baseline characteristics of the selected participants according to tertiles of HCT2h are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The mean BW and GA were 1375.5\u0026thinsp;\u0026plusmn;\u0026thinsp;461.4 g and 29.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6 w, respectively, and there were 122 males (37.4%) and 204 females (62.6%). A total of 265 (81.3%) singleton pregnancies and 61 (18.7%) multiple pregnancies were recorded. Only nine (2.8%) preterm newborns did not receive glucocorticoids prior to delivery, out of the 317 (97.2%) who received prenatal steroids. Of the deliveries, 196 were by cesarean section (60%), and 130 were by normal delivery (39.9%). The Apgar score at one minute was 5.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3, and at five minutes, it was 7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7. Ninety-six percent of patients received resuscitation medicine and/or chest compression in the delivery room, while 82.5% received intubation and positive pressure ventilation. Her temperature at admission was 36.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u0026deg;C. Among the preterm newborns, 260 (79.8%) received lung surfactant, whereas 66 (20.2%) did not. Within 24 hours of birth, 91 (27.9%) preterm infants were extubated, while 111 (34%) accepted intubation while they were in the NICU. Pneumothorax occurred in eleven (3.4%) preterm neonates, and 92 (28.2%) received blood transfusions. All of these preterm babies had a peak bilirubin concentration of 8.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6 mg/dL.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eUnivariate and multivariate analyses of HCT2h and ROP\u003c/h2\u003e \u003cp\u003eThe results of the univariate logistic regression model analyses are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Risk factors for ROP are Etippv, positive pressure ventilation by endotracheal intubation in the delivery room, Drccompmeds, delivery room chest compression and/or resuscitation medication, surfactant, pneumothorax, intubation within 24 hours of life, and intubation any time during the NICU stay. The protective factors included gestational age, 1-minute Apgar score, 5-minute Apgar score, admission temperature in Celsius, peak bilirubin, HCT2h, and vaginal delivery. Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e displays multivariate logistic regression models. HCT2h was negatively linked with the incidence of ROP in all models, including the completely adjusted model (adjusted for all the covariates as listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) and the nonadjusted, minimally adjusted, multiply adjusted, and fully adjusted models. One increase in HCT2h was linked, after multiple correction, to a 9% reduction in the incidence of ROP [OR\u0026thinsp;=\u0026thinsp;0.91; 95% confidence interval (CI): 0.84,0.97; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.008; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e]. For the sensitivity analysis, we also considered HCT2h as a categorical variable (tertile), and we found a similar tendency (\u003cem\u003ep\u003c/em\u003e value for the trend was 0.004; Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eSubgroup Analyses by Adjusted Potential Effect Confounders\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e show that the interactions for BW, sex, and delivery mode in the subgroup analysis were not statistically significant. In the subgroups, we found that GA interacted with HCT2 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of clinical parameters between the no ROP and ROP groups.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;326)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo ROP (n\u0026thinsp;=\u0026thinsp;248)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAny ROP (n\u0026thinsp;=\u0026thinsp;78)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e -value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHCT2(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48.3\u0026thinsp;\u0026plusmn;\u0026thinsp;7.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49.9\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBW (g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1375.5\u0026thinsp;\u0026plusmn;\u0026thinsp;461.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1510.7\u0026thinsp;\u0026plusmn;\u0026thinsp;418.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e945.8\u0026thinsp;\u0026plusmn;\u0026thinsp;299.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGA(w)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.627\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e122 (37.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e91 (36.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (39.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e204 (62.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e157 (63.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e47 (60.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eMultiples\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.595\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e265 (81.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e200 (80.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e65 (83.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61 (18.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48 (19.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13 (16.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDelivery Mode\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.176\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCesarean section\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e196 (60.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e144 (58.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e130 (39.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e104 (41.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eHCT2, hematocrit in the first two hours of life; BW, birth weight; GA, gestational age; Multiple, multiple pregnancy; Apgar1,1-minute Apgar; Apgar5,5-minute Apgar.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical characteristics of the study population according to HCT2 (hematocrit in the first two hours of life).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal (n\u0026thinsp;=\u0026thinsp;326)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eQ1 (n\u0026thinsp;=\u0026thinsp;108)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eQ2 (n\u0026thinsp;=\u0026thinsp;109)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eQ3 (n\u0026thinsp;=\u0026thinsp;109)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e -value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBW(g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1375.5\u0026thinsp;\u0026plusmn;\u0026thinsp;461.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1141.0\u0026thinsp;\u0026plusmn;\u0026thinsp;434.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1397.7\u0026thinsp;\u0026plusmn;\u0026thinsp;471.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1585.7\u0026thinsp;\u0026plusmn;\u0026thinsp;362.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGA(w)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.254\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e122 (37.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e47 (43.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e36 (33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39 (35.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e204 (62.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e61 (56.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e73 (67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e70 (64.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMultiple Pregnancy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.881\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e265 (81.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89 (82.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e89 (81.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e87 (79.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61 (18.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19 (17.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20 (18.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e22 (20.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAns\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (2.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e317 (97.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e105 (97.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e106 (97.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e106 (97.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDelivery Mode\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.413\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCesarean section\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e196 (60.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68 (63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60 (55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e68 (62.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e130 (39.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40 (37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e49 (45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e41 (37.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEtippv\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e269 (82.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e67 (62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e97 (89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e105 (96.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57 (17.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41 (38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12 (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4 (3.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eDrccompmeds\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e313 (96.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100 (92.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e105 (96.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e108 (99.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (4.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8 (7.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (3.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtemp(℃)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e36.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e36.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.348\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurfactant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e260 (79.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65 (60.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e92 (84.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e103 (94.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e66 (20.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43 (39.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17 (15.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (5.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntub1d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e235 (72.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e51 (47.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e86 (78.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e98 (89.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e91 (27.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57 (52.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23 (21.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11 (10.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ePneumothorax\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.224\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e315 (96.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103 (95.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e104 (95.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e108 (99.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (3.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAny intub\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e215 (66.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43 (39.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e77 (70.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95 (87.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e111 (34.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65 (60.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32 (29.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14 (12.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eAny transfusion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e234 (71.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48 (44.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e82 (75.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e104 (95.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e92 (28.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60 (55.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27 (24.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5 (4.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePkbili(mg/dl)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnyrop\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e248 (76.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58 (53.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e87 (79.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e103 (94.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e78 (23.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e50 (46.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22 (20.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (5.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe data are presented as the means\u0026thinsp;\u0026plusmn;\u0026thinsp;SDs or numbers (proportions) for categorical variables.\u003c/p\u003e \u003cp\u003eBW, birth weight; GA, gestational age; Ans, antenatal steroids; Apgar1,1-minute Apgar; Apgar5,5-minute Apgar; Etippv, delivery room intubation and positive pressure ventilation; Drccompmeds, delivery room chest compression and/or resuscitation medication; Atemp, admission temperature in Celsius; Intub1d, intubation within 24 hours of life; Any Intub, intubation any time during the NICU stay; Any transfusion, any pRBC transfusion during the NICU stay; Pkbili, peak bilirubin; Anyrop, retinopathy of prematurity (stage 1\u0026ndash;3); Q1, Q2, and Q3 are quartiles of the HCT2 (hematocrit in the first two hours of life).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eUnivariate logistic regression models evaluating the association between HCT2 (hematocrit in the first two hours of life) and retinopathy of prematurity.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e_value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBW\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1 (0.99\u0026thinsp;~\u0026thinsp;1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.47 (0.39\u0026thinsp;~\u0026thinsp;0.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.88 (0.52\u0026thinsp;~\u0026thinsp;1.49)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.637\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMultiple Pregnancy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.77 (0.39\u0026thinsp;~\u0026thinsp;1.52)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.459\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAns 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.24 (0.05\u0026thinsp;~\u0026thinsp;1.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.066\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.73 (0.65\u0026thinsp;~\u0026thinsp;0.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eApgar5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.64 (0.54\u0026thinsp;~\u0026thinsp;0.75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEtippv\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.12 (4.56\u0026thinsp;~\u0026thinsp;18.27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDrccompmeds\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.79 (1.32\u0026thinsp;~\u0026thinsp;17.45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtemp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.85 (0.51\u0026thinsp;~\u0026thinsp;1.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.512\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurfactant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.76 (3.65\u0026thinsp;~\u0026thinsp;12.51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePneumothorax\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.67 (1.91\u0026thinsp;~\u0026thinsp;48.95)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntub1d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.99 (3.94\u0026thinsp;~\u0026thinsp;12.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnyintub\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.15 (5.14\u0026thinsp;~\u0026thinsp;16.31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAny transfusion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e14.99 (8.11\u0026thinsp;~\u0026thinsp;27.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePkbili\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.56 (0.48\u0026thinsp;~\u0026thinsp;0.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.83 (0.79\u0026thinsp;~\u0026thinsp;0.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.68 (0.4\u0026thinsp;~\u0026thinsp;1.17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.163\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypothermia1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.13 (0.29\u0026thinsp;~\u0026thinsp;4.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.859\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eBW, birth weight; GA, gestational age; Ans, antenatal steroids; Apgar1,1-minute Ap Drccompmeds, delivery room chest compression and/or resuscitation medication gar; Apgar5,5-minute Apgar; Etippv, delivery room intubation and positive pressure ventilation; Drccompmeds, delivery room chest compression and/or resuscitation medication; Atemp, admission temperature in Celsius; Intub1d, intubation within 24 hours of life; Any Intub, intubation any time during the NICU stay; Any transfusion, any pRBC transfusion during the NICU stay; Pkbili, peak bilirubin.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariable-adjusted ORs and 95% CIs of the HCT2 index quartiles associated with retinopathy of prematurity\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eUnadjusted\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eModel1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eModel2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eModel3\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR(95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR(95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eOR(95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eOR(95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.83 (0.79\u0026thinsp;~\u0026thinsp;0.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.91 (0.86\u0026thinsp;~\u0026thinsp;0.97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.9 (0.84\u0026thinsp;~\u0026thinsp;0.96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.91 (0.84\u0026thinsp;~\u0026thinsp;0.97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHCT tertiles\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eRef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eRef\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.27 (0.14\u0026thinsp;~\u0026thinsp;0.49)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.45 (0.2\u0026thinsp;~\u0026thinsp;1.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.057\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.47 (0.2\u0026thinsp;~\u0026thinsp;1.09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.46 (0.18\u0026thinsp;~\u0026thinsp;1.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.096\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQ3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.06 (0.02\u0026thinsp;~\u0026thinsp;0.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.22 (0.08\u0026thinsp;~\u0026thinsp;0.66)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.2 (0.07\u0026thinsp;~\u0026thinsp;0.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.23 (0.07\u0026thinsp;~\u0026thinsp;0.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ep for trend\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.25 (0.17\u0026thinsp;~\u0026thinsp;0.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.47 (0.28\u0026thinsp;~\u0026thinsp;0.79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.46 (0.27\u0026thinsp;~\u0026thinsp;0.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.48 (0.27\u0026thinsp;~\u0026thinsp;0.86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eModel 1 adjusts for BW, GA, sex, and delivery mode\u003c/p\u003e \u003cp\u003eModel 2 was adjusted for Model 1\u0026thinsp;+\u0026thinsp;Multiple Pregnancy\u0026thinsp;+\u0026thinsp;Ans\u0026thinsp;+\u0026thinsp;Apgar1\u0026thinsp;+\u0026thinsp;Apgar5\u003c/p\u003e \u003cp\u003eModel 3 is adjusted for Model 1\u0026thinsp;+\u0026thinsp;Model 2\u0026thinsp;+\u0026thinsp;Etippv\u0026thinsp;+\u0026thinsp;Drccompmeds\u0026thinsp;+\u0026thinsp;Atemp\u0026thinsp;+\u0026thinsp;Surfactant\u0026thinsp;+\u0026thinsp;Pneumothorax\u0026thinsp;+\u0026thinsp;Intub1d\u0026thinsp;+\u0026thinsp;Anytransfusion\u0026thinsp;+\u0026thinsp;Pkbili\u003c/p\u003e \u003cp\u003eRef, reference; HCT2, hematocrit in the first two hours of life; BW, birth weight; GA, gestational age; Ans, antenatal steroids; Apgar1,1-minute Apgar; Apgar5,5-minute Apgar; Etippv, delivery room intubation and positive pressure ventilation; Drccompmeds, delivery room chest compression and/or resuscitation medication; Atemp, admission temperature in Celsius; Intub1d, intubation within 24 hours of life; Any Intub, intubation any time during the NICU stay; Any transfusion, any pRBC transfusion during the NICU stay; Pkbili, peak bilirubin. Q1, Q2 and Q3 are quartiles of HCT2 (hematocrit in the first 2 hours of life).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSubgroup analyses of HCT2 and ROP patients.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSubgroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003en.total\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003en.event_%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ecrude.OR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003ecrude.P_value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eadj.OR_95CI\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eadj.\u003cem\u003ep\u003c/em\u003e_value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e.for.interaction\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGA(w)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e53 (57.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.95 (0.88\u0026thinsp;~\u0026thinsp;1.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.188\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.01 (0.9\u0026thinsp;~\u0026thinsp;1.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.819\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e234\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25 (10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.81 (0.75\u0026thinsp;~\u0026thinsp;0.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.85 (0.76\u0026thinsp;~\u0026thinsp;0.96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBW(g)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;1000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50 (61.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.93 (0.85\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.124\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.99 (0.84\u0026thinsp;~\u0026thinsp;1.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.892\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.073\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;1000,\u0026lt;1500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e112\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24 (21.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.87 (0.8\u0026thinsp;~\u0026thinsp;0.95)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.85 (0.73\u0026thinsp;~\u0026thinsp;0.97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;1500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e133\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.78 (0.66\u0026thinsp;~\u0026thinsp;0.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0 (0\u0026thinsp;~\u0026thinsp;0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSex\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003efemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e122\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31 (25.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.84 (0.77\u0026thinsp;~\u0026thinsp;0.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.91 (0.81\u0026thinsp;~\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.114\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.733\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e204\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e47 (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.83 (0.77\u0026thinsp;~\u0026thinsp;0.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.95 (0.86\u0026thinsp;~\u0026thinsp;1.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.283\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDelivery Mode\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCesarean section\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e196\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52 (26.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.85 (0.8\u0026thinsp;~\u0026thinsp;0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.98 (0.9\u0026thinsp;~\u0026thinsp;1.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.718\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.563\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCT2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e130\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26 (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003e0.8 (0.72\u0026thinsp;~\u0026thinsp;0.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.84 (0.73\u0026thinsp;~\u0026thinsp;0.97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe development of ROP is mainly attributed to prematurity and oxygen delivery. Although the pathophysiology of ROP has been widely investigated, it remains somewhat unknown. There are apparently common risk factors, such as low GA and low BW. The univariate logistic regression models of our study indicated that BW, GA, Apgar1, Apgre5, delivery room intubation and positive pressure ventilation, delivery room chest compressions and/or resuscitation medications, surfactant, pneumothorax, intubation within 24 hours of life, intubation any time during the NICU stay, any pRBC transfusion during the NICU stay, and peak bilirubin were all risk factors for ROP development. Our data also showed that premature infants with ROP had significantly lower GA and BW and lower Apgar1 and Apgar5 than non-ROP infants, which was consistent with the findings of previous studies (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDetermining a possible biomarker of ROP progression in humans is challenging. In recent years, several authors have investigated the possible relationships between routinely tested blood parameters and ROP development, such as a reduced platelet count, and thrombocytopenia has been correlated with severe ROP outcomes (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Our study explored the correlation between the incidence of ROP and HCT2h in extremely preterm infants born before or at 34 weeks of pregnancy. In our study, HCT2h was the earliest blood test parameter that can avoid confounding factors, such as systemic treatment, and is easy to obtain. The incidence of ROP and HCT2h were negatively correlated according to the multiple adjustment model. There was an approximately linear correlation between HCT2h and the incidence of ROP when we looked at HCT2h as a categorical variable. This may be related to the decrease in the oxygen-carrying capacity of the blood caused by low HCT and low hemoglobin(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe results suggest that including early HCT among routinely measured blood parameters may help to identify preterm infants with GA at 28\u0026ndash;34 weeks who may be more prone to ROP well in advance. In this way, we can screen preterm infants at high risk of ROP as early as possible and provide active treatment, thereby reducing the incidence of ROP. The aforementioned statement provides us with novel concepts for the early detection of ROP and for mitigating the risk of ROP through proactive intervention. However, does that mean that if the HCT2 of preterm babies is low, we should administer a blood transfusion. A multicenter randomized trial showed that umbilical cord red blood cell (RBC) transfusion may reduce the severity of ROP in neonates of extreme gestational age (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Moreover, another prospective study compared liberal and restrictive RBC transfusions and demonstrated that no statistically significant differences were observed in ROP incidence between these two groups (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). However, another study has shown that multiple transfusions of RBCs and PLTs are associated with a higher stage of ROP development. (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Previous studies have investigated the potential impact of erythropoietin (EPO) supplementation, iron, or blood transfusions on the development of ROP (\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e), but the results have been inconsistent. Repeated transfusions in preterm infants with anemia of prematurity to replace fetal hemoglobin (HbF) with adult hemoglobin (HbA) are associated with a greater incidence of ROP (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Umbilical cord blood (UCB) contains growth factors and progenitor cells that may affect ROP. Autologous UCB transfusions could reduce the risks associated with heterologous blood products and offer benefits by maintaining physiological HbF levels and potentially XXXimproving postnatal development (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). DDD may be safer or placental transfusion may be performed for preterm babies with a GA between 28 and 32 weeks. However, for extremely preterm infants younger than 28 weeks, delayed cord clamping (DCC) or UCB infusion cannot reduce the incidence of ROP, which may be related to the extremely immature development of these preterm infants.\u003c/p\u003e \u003cp\u003eThe role of HCT2 in ROP is not completely understood. The correlation between low HCT2 and ROP development suggests that blood tests after birth may be predictive of an unfavorable course of ROP and may help to elucidate the pathophysiology of ROP. Early identification of 'at-risk' preterm babies through a simple blood test would also help to identify those babies who are more likely to develop ROP and who need to be monitored more closely, ideally improving the management of this potentially blinding condition. Future multicenter, prospective clinical studies and basic research are required to determine the deeper relationship between low HCT2 and ROP and whether preterm infants with low HCT should receive active transfusion.\u003c/p\u003e \u003cp\u003eThere were certain limitations to this study as well. First, the small sample size of 326 extremely preterm newborns in this study warrants larger sample sizes in future multicenter studies. Second, this study included only American patients. HCT2h is not frequently evaluated in extremely preterm infants in China. When extrapolating the findings of this study to other populations, caution should be exercised. Third, some eligible patients may have been removed from the initial study because this was a secondary analysis of data from a previously published study.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eROP and HCT2h had a negative correlation. A reduced incidence of ROP was linked to a greater level of HCT2h in very preterm infants born at or before 34 weeks of gestation. Further research on this correlation is warranted.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Santa Clara Valley Medical Center\u0026rsquo;s (SCVMC) ethical committee reviewed and approved the studies involving human participants. The participants provided written informed consent to participate in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by the Key Research and Development Plan of Jining City funded by the Jining Science and Technology Bureau (2023YXNS160 and 2023YXNS112), the Cultivation Plan of High-Level Scientific Research Projects at Jining Medical University (JYGC2021FKJ010) and the \u0026quot;Miaopu\u0026quot; Scientific Research Program of the Affiliated Hospital of Jining Medical University (MP-MS-2021-014).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKong Xiaohui designed the study. Yang Ru, Zhang Min, Li Chengshuai, Zhang Rui\u003csup\u003ea\u003c/sup\u003e, Wei Lihua, and Xu Jing collected and analyzed the data. Kong Xiaohui wrote the first draft of the manuscript. Wang Huabin interpreted the results. Ren Xueyun contributed to the refinement of the manuscript. The final manuscript has been read and approved by the authors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Song Dongli (Santa Clara Valley Medical Center) for providing the original data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; information(optional)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWood EH, Chang EY, Beck K, Hadfield BR, Quinn AR, Harper CA. 80 Years of vision: preventing blindness from retinopathy of prematurity. J Perinatol. 2021;41(6):1216\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWoo SJ, Park KH, Lee SY, Ahn SJ, Ahn J, Park KH, et al. The relationship between cord blood cytokine levels and perinatal factors and retinopathy of prematurity: a gestational age-matched case-control study. Invest Ophthalmol Vis Sci. 2013;54(5):3434\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFung C, Cung T, Nelson C, Wang H, Bretz C, Ramshekar A, et al. Retinopathy of prematurity protection conferred by uteroplacental insufficiency through erythropoietin signaling in an experimental Murine Model. Pediatr Res. 2023;94(3):950\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrasad M, Ingolfsland EC, Christiansen SP. Modifiable Risk Factors and Preventative Strategies for Severe Retinopathy of Prematurity. Life. 2023;13(5).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBal S, Ying G-s, Tomlinson L, Binenbaum G. Association of Weight Gain Acceleration With Risk of Retinopathy of Prematurity. JAMA Ophthalmol. 2019;137(11).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlmeida AC, Silva GA, Santini G, Brizido M, Correia M, Coelho C, et al. Correlation between hyperglycemia and glycated albumin with retinopathy of prematurity. Sci Rep. 2021;11(1):22321.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEdwards JM, Edwards LE, Swamy GK, Grotegut CA. Effect of Cord Blood Magnesium Level at Birth on Non-neurologic Neonatal Outcomes. Am J Perinatol. 2019;36(1):3\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHellgren G, Lundgren P, Pivodic A, L\u0026ouml;fqvist C, Nilsson AK, Ley D, et al. Decreased Platelet Counts and Serum Levels of VEGF-A, PDGF-BB, and BDNF in Extremely Preterm Infants Developing Severe ROP. Neonatology. 2021;118(1):18\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRomero-Maldonado S, Montoya-Estrada A, Reyes-Munoz E, Guzman-Grenfell AM, Torres-Ramos YD, Sanchez-Mendez MD, et al. Efficacy of water-based vitamin E solution versus placebo in the prevention of retinopathy of prematurity in very low birth weight infants: A randomized clinical trial. Med (Baltim). 2021;100(31):e26765.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHellstrom A, Nilsson AK, Wackernagel D, Pivodic A, Vanpee M, Sjobom U, et al. Effect of Enteral Lipid Supplement on Severe Retinopathy of Prematurity: A Randomized Clinical Trial. JAMA Pediatr. 2021;175(4):359\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSong D, Jegatheesan P, DeSandre G, Govindaswami B. Duration of Cord Clamping and Neonatal Outcomes in Very Preterm Infants. PLoS ONE. 2015;10(9):e0138829.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarranza-Mendizabal CS, Diaz-Manrique M, Ruiz Mamani PG, White M, Huancahuire-Vega S. Incidence and Risk Factors Associated with Retinopathy of Prematurity in Peru. Clin Ophthalmol. 2021;15:2141\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eParrozzani R, Nacci EB, Bini S, Marchione G, Salvadori S, Nardo D et al. Severe retinopathy of prematurity is associated with early post-natal low platelet count. Sci Rep. 2021;11(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGantz MG, Carlo WA, Finer NN, Rich W, Faix RG, Yoder BA, et al. Achieved oxygen saturations and retinopathy of prematurity in extreme preterms. Arch Dis Child Fetal Neonatal Ed. 2020;105(2):138\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTandon M, Ranjan R, Muralidharan U, Kannan A. Influence of Anaemia on Multifactorial Disease Retinopathy of Prematurity: A Prospective Observational Study. Cureus. 2022.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeofili L, Papacci P, Orlando N, Bianchi M, Pasciuto T, Mozzetta I, et al. BORN study: a multicenter randomized trial investigating cord blood red blood cell transfusions to reduce the severity of retinopathy of prematurity in extremely low gestational age neonates. Trials. 2022;23(1):1010.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee EY, Kim SS, Park GY, Lee SH. Effect of red blood cell transfusion on short-term outcomes in very low birth weight infants. Clin Experimental Pediatr. 2020;63(2):56\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKnee D, Knoop S, Davis AT, Rawson B, DiCarlo A, Olivero R. Outcomes after implementing restrictive blood transfusion criteria in extremely premature infants. J Perinatol. 2019;39(8):1089\u0026ndash;97.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHengartner T, Adams M, Pfister RE, Snyers D, McDougall J, Waldvogel S, et al. Associations between Red Blood Cell and Platelet Transfusions and Retinopathy of Prematurity. Neonatology. 2020;117(5):562\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFauchere JC, Koller BM, Tschopp A, Dame C, Ruegger C, Bucher HU, et al. Safety of Early High-Dose Recombinant Erythropoietin for Neuroprotection in Very Preterm Infants. J Pediatr. 2015;167(1):52\u0026ndash;7. e1-3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDani C, Bertini MFRG, Martelli E, Pezzati M, Rubaltelli FF. The role of blood transfusions and iron intake on retinopathy of prematurity. Early Hum Dev. 2001;62(2001):57\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAher SM, Ohlsson A. Early versus late erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants. Cochrane Database Syst Reviews. 2020;2020:2.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePellegrino C, Papacci P, Beccia F, Serrao F, Cantone GV, Cannetti G et al. Differences in Cerebral Tissue Oxygenation in Preterm Neonates Receiving Adult or Cord Blood Red Blood Cell Transfusions. JAMA Netw Open. 2023;6(11).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlaser K, H\u0026auml;rtel C, Dammann O, Herting E, Andres O, Speer CP, et al. Erythrocyte transfusions are associated with retinopathy of prematurity in extremely low gestational age newborns. Acta Paediatr. 2023;112(12):2507\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTorrejon-Rodriguez L, Pinilla-Gonzalez A, Lara Cant\u0026oacute;n I, Albiach-Delgado A, Cascant-Vilaplana MM, Cernada M et al. Effect of autologous umbilical cord blood transfusion in the development of retinopathy of prematurity: randomized clinical trial \u0026ndash; study protocol. Front Pead. 2023;11.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Hematocrit, Retinopathy of prematurity, Premature infant, Retrospective study","lastPublishedDoi":"10.21203/rs.3.rs-4141695/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4141695/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e \u003cp\u003eOur study investigated the association between hematocrit in the first two hours (HCT2h) of life and retinopathy of prematurity (ROP).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eData were obtained from an observational study of the DRYAD database. The study was conducted at the Santa Clara Valley Medical Center (SCVMC). Data on preterm babies whose gestational age (GA) was \u0026lt;\u0026thinsp;34 weeks were collected prospectively from January 2008 to February 2014. Logistic regression was applied to explore the association between HCT2h and ROP.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 326 very preterm infants born at or earlier than 34 weeks were included. The incidence of any ROP was 23.9%, and the incidence of severe ROP was 4.6%. The HCT2h, birth weight, GA, Apgar1 min, and Apgar5 min of any ROP group were significantly lower than those of preterm babies without ROP (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Sex differences, the rate of multiples, and delivery mode between the two groups were not statistically significant (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). We classified HCT2h into three levels, and after multivariate logistic regression, we found that high HCT2h remained a significant protective factor against ROP (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Through subgroup analysis, we observed that among preterm infants with a GA of 28 weeks or more, there was a significant inverse association between a 1% increase in HCT2h and a 17% reduction in the occurrence of ROP.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eWe found that a greater HCT2h was associated with a lower incidence of ROP among preterm infants born between 28 and 34 weeks of gestation.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eThis was a retrospective study and the data were from the DRYAD database. Santa Clara Valley Medical Center\u0026rsquo;s (SCVMC) ethical committee reviewed and approved the studies involving human participants. The participants provided their written informed consent to participate in this study. We did not perform any extra interventions.\u003c/p\u003e","manuscriptTitle":"Association between Hematocrit in the First Two Hours of Life and Retinopathy during Prematurity: A Retrospective Study from DRYAD","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-29 19:08:16","doi":"10.21203/rs.3.rs-4141695/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-10-09T09:21:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-09-10T14:55:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"180587170332839588641944006782516036976","date":"2024-08-20T08:30:31+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-25T16:07:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"88210841293129092273390004955190619309","date":"2024-07-25T07:07:16+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-21T12:37:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"310297269213473575210605086973251014131","date":"2024-07-18T19:37:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"189230475262579950549709468339022698256","date":"2024-07-18T19:28:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"254142633818233924298219214874210412530","date":"2024-07-14T06:32:23+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-05T07:20:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-06-18T12:52:34+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-03-26T17:04:27+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-03-26T06:56:59+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pediatrics","date":"2024-03-21T07:53:23+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a3e14a58-5cac-4249-964e-b955b2898419","owner":[],"postedDate":"March 29th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-03-10T19:48:00+00:00","versionOfRecord":{"articleIdentity":"rs-4141695","link":"https://doi.org/10.1186/s12887-025-05533-8","journal":{"identity":"bmc-pediatrics","isVorOnly":false,"title":"BMC Pediatrics"},"publishedOn":"2025-03-08 15:58:41","publishedOnDateReadable":"March 8th, 2025"},"versionCreatedAt":"2024-03-29 19:08:16","video":"","vorDoi":"10.1186/s12887-025-05533-8","vorDoiUrl":"https://doi.org/10.1186/s12887-025-05533-8","workflowStages":[]},"version":"v1","identity":"rs-4141695","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4141695","identity":"rs-4141695","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}