Anatomical location of small bowel atresia independently predicts preterm delivery: A two-center study in southern Japan

Anatomical location of small bowel atresia independently predicts preterm delivery: A two-center study in southern Japan | 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 Anatomical location of small bowel atresia independently predicts preterm delivery: A two-center study in southern Japan Toshio Harumatsu, Yudai Tsuruno, Ayaka Nagano, Koshiro Sugita, and 16 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9492264/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Purpose Small bowel atresia (SBA) presents with variable clinical features depending on anatomical location. We investigated the relationship between atresia location and preterm delivery. Methods We retrospectively reviewed 58 patients who underwent surgery for SBA at two institutions between April 2000 and March 2024. Patients were divided into preterm (< 37 weeks, n = 28) and term (≥ 37 weeks, n = 30) groups. Clinical characteristics, prenatal findings, anatomical location, and surgical outcomes were compared. A logistic regression analysis identified independent predictors of preterm delivery. Results Preterm infants showed lower birth weight (1988 ± 731 g vs. 3062 ± 395 g, p < 0.001) and higher rates of prenatal diagnosis (85.7% vs. 60.0%, p = 0.040), polyhydramnios (42.9% vs. 13.3%, p = 0.018), and bowel dilatation (78.5% vs. 50.0%, p = 0.031). The distance from the ligament of Treitz was shorter in preterm infants (31.6 ± 31.5 cm vs. 103.6 ± 39.9 cm, p < 0.001). Jejunal atresia was more common in preterm infants (71.4% vs. 6.7%; p < 0.001). A strong correlation was observed between birth weight and atresia distance (r = 0.63, p < 0.001). In a multivariable analysis, proximal atresia was an independent predictor of preterm delivery (adjusted OR 0.79 per 10 cm, 95% CI 0.65–0.96, p = 0.018). Conclusion Proximal SBA was independently associated with preterm delivery. Prenatal identification may facilitate appropriate perinatal management and parental counseling. Small bowel atresia Preterm delivery Jejunal atresia Polyhydramnios Prenatal diagnosis Figures Figure 1 Figure 2 Introduction Small bowel atresia presents with variable clinical features depending on the anatomical location. Despite advances in neonatal care, this condition remains associated with significant morbidity, particularly short bowel syndrome and feeding difficulties [ 1 , 2 ]. The anatomical location of intestinal atresia may influence perinatal outcomes, including delivery timing. The currently accepted vascular accident theory, first confirmed by Louw and Barnard, is supported by various clinical presentations, ranging from isolated atresia to extremely rare cases of near-complete jejunoileal absence [ 3 ]. However, the precise relationship between atresia location and gestational age at delivery has not been thoroughly investigated as a continuous variable. Advances in prenatal ultrasonography have improved the diagnostic accuracy of small bowel atresia [ 4 , 5 ]. However, whether these prenatal findings can predict delivery timing and facilitate appropriate perinatal management planning remains unclear. This study aimed to investigate the relationship between the anatomical location of small bowel atresia and preterm delivery and identify independent predictors of preterm birth in this patient population. Materials and methods 1.1. Study design and patient population This was a retrospective observational study of patients with small-bowel atresia who underwent surgical treatment at two institutions (Kagoshima University Hospital and Kagoshima City Hospital) between April 2000 and March 2024. Inclusion criteria were all consecutive patients with surgically confirmed small bowel atresia (jejunal or ileal atresia) during the study period. Patients with duodenal atresia or colonic atresia were not included in this study. There were no other specific exclusion criteria. A total of 58 patients with small-bowel atresia were enrolled. Patients were classified into two groups based on gestational age at delivery: preterm (< 37 weeks, n = 28) and term (≥ 37 weeks, n = 30). The patients were further categorized based on the anatomical location of the atresia relative to the ligament of Treitz. Cases of multiple atresia were classified according to the most proximal atretic site. The mode of delivery was determined by obstetricians based on maternal and fetal indications. Cesarean section was performed for standard obstetric indications including non-reassuring fetal status, breech presentation, and other maternal or fetal complications. The diagnosis of small bowel atresia itself was not considered an absolute indication for cesarean delivery. 1.2. Definition of jejunal and ileal atresia The small bowel is anatomically divided into jejunum and ileum based on the total length of the small intestine [ 6 ]. Jejunal atresia was defined as atresia located within the proximal two-fifths of the total small-bowel length from the ligament of Treitz. Ileal atresia was defined as atresia located in the distal three-fifths of the small bowel. 1.3. Data collection Patient demographics, prenatal findings, delivery characteristics, anatomical characteristics of intestinal atresia, surgical procedures, and short-term outcomes were collected from the medical records. Prenatal findings included the prenatal diagnosis status, gestational age at the diagnosis, polyhydramnios, bowel dilatation on ultrasonography, and fetal ascites. Anatomical characteristics included the distance from the ligament of Treitz to the atresia site and classification as jejunal or ileal atresia. Surgical data included the age at surgery, type of surgical procedure performed (primary anastomosis, stoma creation, or membrane excision), and in-hospital mortality. 1.4. Surgical management All patients underwent surgical intervention for small-bowel atresia. The surgical approach was determined based on the anatomical characteristics of atresia, bowel condition, and overall clinical status. Primary anastomosis was performed when the bowel ends were viable with adequate blood supply and the luminal diameter discrepancy was manageable. Stoma creation was selected in cases of multiple atresia, questionable bowel viability, severe contamination, or extremely low birth weight. Membrane excision was performed for type I atresia with a membranous obstruction. 1.5. Statistical analyses Continuous variables were expressed as the mean ± standard deviation (SD) or median with interquartile range (IQR), as appropriate. Categorical variables are presented as numbers and percentages. Comparisons between the preterm and term groups were performed using the Mann-Whitney U test for continuous variables with non-normal distribution, Student's t-test for normally distributed continuous variables, and Fisher's exact test or chi-square test for categorical variables. Univariable and multivariable logistic regression analyses were performed to identify independent predictors of preterm delivery. Variables with p < 0.1 in the univariate analysis were included in the multivariable model. Results are expressed as odds ratios (ORs) with 95% confidence intervals (CIs). The correlation between the distance from the ligament of Treitz and birth weight was evaluated using the Spearman's rank correlation coefficient. For the dose-response analysis, patients were divided into three gestational age groups: early preterm (< 34 weeks), late preterm (34–36 weeks), and term (≥ 37 weeks). The Kruskal-Wallis test was used for overall comparison among the three groups, followed by post-hoc pairwise comparisons using Dunn's test with Bonferroni correction. All statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), a graphical user interface for R (R Foundation for Statistical Computing, Vienna, Austria). More precisely, it is a modified version of the R commander designed to add statistical functions frequently used in biostatistics [ 7 ]. Statistical significance was set at p < 0.05. All tests were two sided. 1.6. Ethical approval A retrospective chart review and data collection were performed after institutional review board approval was received in accordance with the Ethical Guidelines for Medical and Health Research Involving Human Subjects by the Ministry of Health, Labor, and Welfare of Japan in 2014. This study complied with the 1964 Declaration of Helsinki (revised in 2013) and was approved by the Research Ethics Committee of Kagoshima University Hospital (registration number: 210329). All participants and their parents provided informed consent for registration in this study. Results 2.1. Patient characteristics The clinical characteristics of the preterm and term groups are presented in Table 1. The preterm group had a significantly lower birth weight than the term group (1988 ± 731 g vs. 3062 ± 395 g, p < 0.001). Male sex was significantly less common in the preterm group than in the term group (25.0% vs. 70.0%, p < 0.001). Regarding prenatal findings, prenatal diagnoses were made more frequently in the preterm group than in the term group (85.7% vs. 60.0%, p = 0.040). The gestational age at the diagnosis in patients with a prenatal diagnosis was significantly earlier in the preterm group (29.0 ± 4.1 weeks vs. 32.5 ± 4.1 weeks, p = 0.011). Polyhydramnios was more frequently observed in the preterm group (42.9% vs. 13.3%, p = 0.018). Bowel dilatation on ultrasonography was also detected more frequently in the preterm group (78.5% vs. 50.0%, p = 0.031). There was no significant difference in the incidence of fetal ascites between the two groups (10.7% vs. 6.7%, p = 0.67). Cesarean delivery was performed significantly more frequently in the preterm group than in the term group (46.4% vs. 13.3%, p = 0.009). The incidence of umbilical cord ulcers did not differ between groups (3.6% vs. 3.3%, p = 1.000). 2.2. Anatomical characteristics of intestinal atresia The anatomical characteristics stratified by gestational age at delivery are shown in Table 2. The distance from the ligament of Treitz to the atresia site was significantly shorter in the preterm group compared to the term group (mean: 31.6 ± 31.5 cm vs. 103.6 ± 39.9 cm, p < 0.001; median: 18 cm [IQR 5.0–57.5] vs. 100 cm [IQR 80.25–126.5]). Regarding anatomical classification, jejunal atresia was significantly more common in the preterm group (71.4% vs. 6.7%, p < 0.001), while ileal atresia was predominant in the term group (28.6% vs. 93.3%). The Spearman correlation coefficient between the distance from the ligament of Treitz and birth weight was 0.63 ( p < 0.001), indicating a strong positive correlation. As illustrated in Figure 1, proximal atresia was associated with lower birth weight. 2.3. Multivariable analysis for preterm delivery The results of the logistic regression analysis are presented in Table 3. In the univariate analysis, the distance from the ligament of Treitz (per 10 cm increase) was significantly associated with reduced odds of preterm delivery (crude OR 0.78, 95% CI 0.65–0.94; p = 0.009). Polyhydramnios was also associated with increased odds of preterm delivery (crude OR 4.74, 95% CI 1.18–23.74, p = 0.018). In the multivariable analysis adjusted for both variables, the distance from the ligament of Treitz remained an independent predictor of preterm delivery (adjusted OR 0.79, 95% CI 0.65–0.96, p = 0.018). This OR of 0.79 indicates that each 10 cm increase in the distance from the ligament of Treitz is associated with an approximately 21% reduction in the odds of preterm delivery, meaning that proximal atresia substantially elevates preterm birth risk in a dose-dependent manner. However, the association between polyhydramnios and preterm delivery was not significant after adjustment (adjusted OR 1.33, 95% CI 0.19–9.46, p = 0.774). 2.4. Surgical procedures and short-term outcomes Table 4 presents the surgical and clinical outcomes of the patients. The median age at operation did not differ significantly between the groups (1 day [IQR 0–2.25] in the preterm group vs. 1 day [IQR 1–2.0] in the term group, p = 0.310). The distribution of surgical procedures differed significantly between the two groups ( p = 0.0024). Primary anastomosis was performed in 53.6% and 90.0% of the preterm and term groups, respectively. Stoma creation was required in 25.0% and 10.0% of the preterm and term groups, respectively. Membrane excision was performed exclusively in the preterm group (21.4% vs 0%). In-hospital mortality occurred in 2 patients (3.4%) in the preterm group (9.5% vs. 0%, p = 0.229). Both deaths were associated with short bowel syndrome caused by multiple intestinal atresia in one case and intrauterine midgut volvulus in the other. 2.5. Dose-response relationship across gestational age groups Figure 2 illustrates the dose-response relationship by comparing the three gestational age groups. The Kruskal-Wallis test showed significant differences among the three groups ( p < 0.001). A post-hoc analysis using Dunn's test with Bonferroni correction revealed significant differences between the early preterm and term groups ( p < 0.001), and between the late preterm and term groups ( p = 0.005). However, no significant difference was observed between the early and late preterm groups ( p = 0.22). Discussion In the present study, we retrospectively reviewed our two institutions' experiences with patients with small bowel atresia and investigated the relationship between the anatomical location of atresia and preterm delivery to identify independent predictors of preterm birth. The major findings of this study were as follows: (1) the distance from the ligament of Treitz to the atresia site was an independent predictor of preterm delivery in the multivariable analysis; (2) polyhydramnios showed a significant association with preterm delivery in the univariate analysis but became non-significant after adjusting for the atresia location; (3) a dose-response relationship was observed across the three gestational age groups, with progressively shorter distances from the ligament of Treitz in the earlier gestational age groups; (4) a strong positive correlation was found between the distance from the ligament of Treitz and birth weight. This study demonstrated that the anatomical location of small bowel atresia, measured as the distance from the ligament of Treitz, is an independent predictor of preterm delivery. These findings have several important clinical implications. First, prenatal identification of the atresia location could serve as a prognostic marker for the preterm delivery risk, allowing clinicians to implement appropriate monitoring and prepare for premature birth. Second, our results indicate that the relationship between the atresia location and gestational age is continuous rather than categorical, indicating that even small differences in the atresia location may influence the timing of delivery. Our analysis revealed that polyhydramnios was not significant after adjusting for atresia location. This statistical finding suggests that polyhydramnios is not an independent cause of preterm delivery but rather a consequence of proximal obstruction. This distinction is clinically meaningful because it implies that treating polyhydramnios alone may not effectively reduce preterm delivery risk unless underlying mechanical obstruction is addressed. The fundamental driver of preterm birth appears to be the anatomical position of atresia. Nakamura et al. demonstrated that elevated bile acid concentrations in the amniotic fluid (≥10 μmol/L) were strongly associated with umbilical cord ulcers and intrauterine fetal death in intestinal atresia [8]. Recent histological studies have supported this hypothesis. Garg et al. demonstrated that light microscopy failed to detect major abnormalities in the proximal dilated bowel in 84% of jejunoileal atresia cases, contradicting previous reports of extensive histological damage. They concluded that bowel plication rather than massive resection should be preferred, as the dilated bowel retains its structural integrity [9]. The dose-response relationship we observed strengthens the causal inference between proximal atresia and preterm delivery. When patients were stratified into three gestational age groups, the distance from the ligament of Treitz showed a progressive stepwise pattern. This gradient effect supports a biological mechanism rather than a mere association, suggesting that the degree of fetal swallowing impairment increases proportionally with the proximity of the obstruction. Previous studies have documented an association between jejunal atresia and adverse perinatal outcomes. Vecchia et al. reported that jejunal atresia was associated with higher complication rates and poorer long-term outcomes than more distal lesions [1]. Fung et al. found that the distance from the ligament of Treitz was significantly shorter in preterm infants [10]. However, their analysis primarily used categorical comparisons rather than examining distance as a continuous variable in a dose-response analysis. Our study extends these observations by demonstrating a quantitative dose-response relationship using continuous variables, providing more granular prognostic information. Furthermore, our multivariate analysis revealed that polyhydramnios acts as a mediating factor rather than an independent predictor, a distinction not previously reported in the literature. Regarding feeding difficulties, Wang et al. identified several predictors of prolonged time to full enteral nutrition [2], which is relevant because infants with proximal atresia and preterm birth face compounded nutritional risks. Our results have direct implications for prenatal counseling. When a fetal ultrasound examination identifies proximal small-bowel atresia with associated polyhydramnios, obstetricians can estimate preterm delivery risk based on the estimated distance from the ligament of Treitz. This allows for proactive planning, including delivery at tertiary centers with both neonatal intensive care and pediatric surgical expertise. Specifically, prenatal identification of proximal atresia enables consideration of antenatal corticosteroids for fetal lung maturation, enhanced surveillance of amniotic fluid volume and fetal well-being, and early preparation of the neonatal and surgical teams for a complex surgical newborn requiring prompt intervention. Increased fetal surveillance may be warranted in cases of proximal atresia, particularly given the risks highlighted by Nakamura et al. regarding umbilical cord ulceration [8]. The strong correlation between atresia location and birth weight raises the question of whether our findings simply reflect fetal size. However, the distance from the ligament of Treitz remained significant even after adjusting for confounding factors, suggesting that anatomical position exerts an effect independent of fetal size. Biological plausibility supports a causal mechanism whereby proximal obstruction leads to impaired fetal swallowing, which in turn results in polyhydramnios, subsequently causing uterine overdistension, and ultimately triggering preterm labor [11,12]. The combination of proximal atresia and preterm birth may have confounding effects on the long-term outcomes. When combined with a potentially shorter residual bowel length after surgical correction, these patients face elevated risks of short bowel syndrome and intestinal failure. In our series, both deaths occurred in the preterm group and were attributable to short bowel syndrome resulting from multiple intestinal atresia and intrauterine midgut volvuli. As emphasized by Fung et al., bowel length preservation is paramount [10]. Limitations This study had several limitations. First, the retrospective design limits causal inferences. Second, the relatively small sample sizes of the two institutions may limit generalizability. Third, we observed an unexpected higher proportion of female infants in the preterm group (75.0% vs. 30.0%), which contradicts the generally recognized male predominance in preterm births. This finding may reflect the small sample size and possible selection bias in our cohort. The relationship between proximal intestinal atresia and sex distribution has not been previously reported and warrants further investigation in larger studies. Fourth, the long-term outcomes, including neurodevelopmental status, were not evaluated. Future prospective multicenter studies with larger cohorts are needed to validate our findings and to develop clinical prediction models. Finally, the retrospective design precluded systematic distinction between spontaneous and iatrogenic preterm delivery; confounding by obstetric decision-making, such as elective early delivery for maternal or fetal indications unrelated to the atresia itself, cannot be entirely excluded. Future prospective studies should systematically record the indication for delivery to allow for this distinction. Conclusions This study demonstrated that proximal small bowel atresia, measured by the distance from the ligament of Treitz, is an independent predictor of preterm delivery. Polyhydramnios acts as a mediating factor rather than an independent cause. The dose-response relationship observed across gestational age groups strengthens the evidence for causality. Prenatal identification of the atresia location may facilitate appropriate perinatal management and parental counseling, enabling delivery planning at tertiary centers equipped with neonatal intensive care and pediatric surgical expertise. Future prospective studies are warranted to validate these findings and develop clinical prediction models. Declarations Author contributions T.H., A.N., and K.S. wrote the manuscript. S.O. and K.Y. prepared the tables and reviewed the literature. Y.T., Y.T., N.N., and C.K. collected data based on medical records, and A.Y., H.O., T.K., E.H., T.K., M.T., and T.T. provided conceptual advice. S.I. critically reviewed the manuscript and supervised the data-collection process. All authors have reviewed the manuscript. Data availability The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request. Declarations Conflict of interest The authors declare no conflicts of interest in association with the present study. Acknowledgments We thank Mr. Brian Quinn for his comments and assistance with this manuscript. This study was supported by a research grant from The Mother and Child Health Foundation, a research grant from the Kawano Masanori Memorial Public Interest Incorporated Foundation for Promotion of Pediatrics, and Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS: 25K22713, 25K11062, 25K11154, 25K11847, 25K11871, 24K06285, 24K15813, 23K20735, 23K07281, 23K08031, 23K08052, 23K11934). References Dalla Vecchia LK, Grosfeld JL, West KW, Rescorla FJ, Scherer LR, Engum SA (1998) Intestinal atresia and stenosis: a 25-year experience with 277 cases. Arch Surg 133(5):490–496 discussion 496–497 Wang J, Du L, Cai W, Pan W, Yan W (2014) Prolonged feeding difficulties after surgical correction of intestinal atresia: a 13-year experience. J Pediatr Surg 49(11):1593–1597 Tripathy PK, Ray BK, Mohanty HK (2017) Congenital absence of jejunum and ileum: A case report and literature review. Afr J Paediatr Surg 14(3):53–55 Ju H, Feng S, Huang Y (2022) Diagnostic value of the microcolon using ultrasonography in small bowel atresia. BMC Pediatr 22(1):576 Hao J, Zhang Y, Tianyu L, Bo S, Shu F, Feng S, Chao J, Ying H (2019) Preliminary Investigation of the Diagnosis of Neonatal Congenital Small Bowel Atresia by Ultrasound. Biomed Res Int 2019:7097159 Vinit N, Mitanchez D, Lemale J, Garel C, Jouannic JM, Hervieux E, Audry G, Irtan S (2021) How can we improve perinatal care in isolated multiple intestinal atresia? A retrospective study with a 30-year literature review. Arch Pediatr 28(3):226–233 Kanda Y (2013) Investigation of the freely available easy-to-use software 'EZR' for medical statistics. Bone Marrow Transpl 48(3):452–458 Nakamura N, Ozawa K, Wada S, Matsuoka K, Yoshioka T, Sugibayashi R, Sago H (2019) Umbilical Cord Ulcer and Intrauterine Death in Fetal Intestinal Atresia. Fetal Diagn Ther 46(5):313–318 Garg V, Puri A, Sakhuja P (2020) Novel insights into the histology of jejunoileal atresia and its therapeutic implications. J Pediatr Surg 55(12):2630–2634 Fung ACH, Lee MK, Lui MPK, Lip LY, Chung PHY, Wong KKY (2023) Primary anastomosis is the preferred surgical approach for proximal intestinal atresia: a retrospective 20-year analysis. Pediatr Surg Int 39(1):99 Rubio EI, Blask AR, Badillo AT, Bulas DI (2017) Prenatal magnetic resonance and ultrasonographic findings in small-bowel obstruction: imaging clues and postnatal outcomes. Pediatr Radiol 47(4):411–421 John R, D'Antonio F, Khalil A, Bradley S, Giuliani S (2015) Diagnostic Accuracy of Prenatal Ultrasound in Identifying Jejunal and Ileal Atresia. Fetal Diagn Ther 38(2):142–146 Tables Table 1 Patient characteristics and perinatal findings stratified by gestational age at delivery Characteristic Overall (n = 58) Preterm (n = 28) Term (n = 30) p value OR (95% CI) Patient demographics Birth weight (g), mean ± SD 2571 ± 778 1988 ± 731 3062 ± 395 < 0.001 - Male gender, n (%) 28 (48.3) 7 (25.0) 21 (70.0) < 0.001 0.14 (0.03–0.52) Prenatal findings Prenatal diagnosis, n (%) 42 (72.4) 24 (85.7) 18 (60.0) 0.040 3.9 (0.97–19.44) Gestational age at diagnosis (weeks), mean ± SD 31.2 ± 4.5 29.0 ± 4.1 32.5 ± 4.1 0.011 - Polyhydramnios, n (%) 16 (27.6) 12 (42.9) 4 (13.3) 0.018 4.74 (1.18–23.74) Bowel dilatation on ultrasound, n (%) 37 (63.8) 22 (78.5) 15 (50.0) 0.031 3.58 (1.02–14.05) Fetal ascites, n (%) 5 (8.6) 3 (10.7) 2 (6.7) 0.67 1.67 (0.18–21.45) Delivery characteristics Cesarean delivery, n (%) 17 (29.3) 13 (46.4) 4 (13.3) 0.009 5.46 (1.37–27.27) Umbilical cord ulcer, n (%) 2 (3.4) 1 (3.6) 1 (3.3) 1.000 1.07 (0.01–87.12) OR, odds ratio; CI, confidence interval; SD, standard deviation. Table 2 Anatomical characteristics of intestinal atresia and correlation with gestational age at delivery Characteristic Overall (n = 58) Preterm (n = 28) Term (n = 30) p value Location of atresia Distance from Treitz ligament (cm), mean ± SD 67.3 ± 45.2 31.6 ± 31.5 103.6 ± 39.9 < 0.001 Distance from Treitz (cm), median (IQR) 60.0 (9.5-91.75) 18 (5.0-57.5) 100 (80.25–126.5) Anatomical classification Jejunal atresia, n (%) 22 (37.9) 20 (71.4) 2 (6.7) < 0.001 Ileal atresia, n (%) 36 (62.1) 8 (28.6) 28 (93.3) Correlation with birth weight Spearman correlation coefficient (TL distance vs birth weight) r = 0.63 - - < 0.001 *Per 10 cm increase in distance from ligament of Treitz SD, standard deviation; IQR, interquartile range; TL, Treitz ligament. Table 3 Multivariable logistic regression analysis for preterm delivery: parsimonious model accounting for sample size constraints Variable Univariate analysis Multivariable analysis Crude OR 95% CI p value Adjusted OR* 95% CI p value Distance from Treitz ligament (per 10 cm) 0.78 0.65–0.94 0.009 0.79 0.65–0.96 0.018 Polyhydramnios (present vs absent) 4.74 1.18–23.74 0.018 1.33 0.19–9.46 0.774 OR, odds ratio; CI, confidence interval. Table 4 Surgical procedures and short-term outcomes stratified by gestational age at delivery Outcome Overall (n = 58) Preterm < 37 weeks (n = 28) Term ≥ 37 weeks (n = 30) P value Surgical characteristics Age at operation (days), median (IQR) 1 (0–2) 1 (0-2.25) 1 (1–2.0) 0.310 Surgical procedure, n (%) 0.0024 - Primary anastomosis 42 (72.4) 15 (53.6) 27 (90.0) - - Stoma creation 10 (17.2) 7 (25.0) 3 (10.0) - - Membrane excision 6 (10.3) 6 (21.4) 0 (0) - Clinical outcomes In-hospital mortality, n (%) 2 (3.4) 2 (9.5) 0 (0) 0.229 IQR, interquartile Range. Additional Declarations No competing interests reported. Supplementary Files ManuscriptHarumatsuacceptance2026.pdf Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 26 Apr, 2026 Reviewers agreed at journal 26 Apr, 2026 Reviewers invited by journal 24 Apr, 2026 Editor assigned by journal 24 Apr, 2026 Submission checks completed at journal 24 Apr, 2026 First submitted to journal 22 Apr, 2026 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-9492264","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":629780969,"identity":"033f80ea-a185-4d84-929d-0a28e464e82e","order_by":0,"name":"Toshio Harumatsu","email":"","orcid":"","institution":"Department of Pediatric Surgery, Research Field in Medical and Health Sciences, Medical and Dental Area, Research and Education Assembly, Kagoshima 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University","correspondingAuthor":false,"prefix":"","firstName":"Keisuke","middleName":"","lastName":"Yano","suffix":""},{"id":629780995,"identity":"7b19f9a4-5792-4d52-9111-25443078eb70","order_by":9,"name":"Tomonori Kurimoto","email":"","orcid":"","institution":"Kagoshima City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tomonori","middleName":"","lastName":"Kurimoto","suffix":""},{"id":629781002,"identity":"0dabb535-5003-4339-8241-68b0d988eda1","order_by":10,"name":"Asataro Yara","email":"","orcid":"","institution":"Kagoshima City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Asataro","middleName":"","lastName":"Yara","suffix":""},{"id":629781003,"identity":"e05cae0e-dc41-4b22-bbb4-e9f712c4b65c","order_by":11,"name":"Hiroki Otsuka","email":"","orcid":"","institution":"Kagoshima City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hiroki","middleName":"","lastName":"Otsuka","suffix":""},{"id":629781005,"identity":"ee9fed93-8315-4c7a-b449-33e3c5b48a74","order_by":12,"name":"Shun Onishi","email":"","orcid":"","institution":"Department of Pediatric Surgery, Research Field in Medical and Health Sciences, Medical and Dental Area, Research and Education Assembly, Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Shun","middleName":"","lastName":"Onishi","suffix":""},{"id":629781008,"identity":"7875f6c9-1af7-4979-89f8-441edecdc542","order_by":13,"name":"Koji Yamada","email":"","orcid":"","institution":"Department of Pediatric Surgery, Research Field in Medical and Health Sciences, Medical and Dental Area, Research and Education Assembly, Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Koji","middleName":"","lastName":"Yamada","suffix":""},{"id":629781012,"identity":"1790347c-1910-41c5-a71d-87dc638c4254","order_by":14,"name":"Waka Yamada","email":"","orcid":"","institution":"Department of Pediatric Surgery, Research Field in Medical and Health Sciences, Medical and Dental Area, Research and Education Assembly, Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Waka","middleName":"","lastName":"Yamada","suffix":""},{"id":629781013,"identity":"20099500-8687-417b-be95-7b11b85b6c8d","order_by":15,"name":"Eiji Hirakawa","email":"","orcid":"","institution":"Kagoshima City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Eiji","middleName":"","lastName":"Hirakawa","suffix":""},{"id":629781014,"identity":"02f16aaa-cb8a-4f49-ad72-8caa0f072d88","order_by":16,"name":"Takafumi Kawano","email":"","orcid":"","institution":"Department of Pediatric Surgery, Research Field in Medical and Health Sciences, Medical and Dental Area, Research and Education Assembly, Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Takafumi","middleName":"","lastName":"Kawano","suffix":""},{"id":629781015,"identity":"59adba28-7277-4e06-8e78-9aaedc5af9e4","order_by":17,"name":"Motofumi Torikai","email":"","orcid":"","institution":"Kagoshima City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Motofumi","middleName":"","lastName":"Torikai","suffix":""},{"id":629781016,"identity":"5ebb218c-9095-4c2b-9574-b15970580301","order_by":18,"name":"Takuya Tokuhisa","email":"","orcid":"","institution":"Kagoshima City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Takuya","middleName":"","lastName":"Tokuhisa","suffix":""},{"id":629781017,"identity":"eb305a06-a133-44d5-84ef-c7662ea76d4b","order_by":19,"name":"Satoshi Ieiri","email":"data:image/png;base64,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","orcid":"","institution":"Department of Pediatric Surgery, Research Field in Medical and Health Sciences, Medical and Dental Area, Research and Education Assembly, Kagoshima University","correspondingAuthor":true,"prefix":"","firstName":"Satoshi","middleName":"","lastName":"Ieiri","suffix":""}],"badges":[],"createdAt":"2026-04-22 07:12:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9492264/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9492264/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108838584,"identity":"73f999ec-0231-4eee-9376-bbe4dbcd880b","added_by":"auto","created_at":"2026-05-09 00:37:51","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":160010,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCorrelation between birth weight and atresia location\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003er\u003c/em\u003e, Spearman's rank correlation coefficient.\u003c/p\u003e","description":"","filename":"HarumatsuetalFigure1forPSIWOFAPS2025.png","url":"https://assets-eu.researchsquare.com/files/rs-9492264/v1/c72e5f685ac552a6e4bb596d.png"},{"id":108838586,"identity":"c9d0c3e3-77c7-4500-83ec-9d18685a7116","added_by":"auto","created_at":"2026-05-09 00:37:51","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":207460,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDose-response relationship between atresia location and gestational age groups\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"HarumatsuetalFigure2forPSIWOFAPS2025.png","url":"https://assets-eu.researchsquare.com/files/rs-9492264/v1/813b4afd33c9cbbd64f5b0af.png"},{"id":109249239,"identity":"ea15ef94-c791-4d95-bb7f-b3fb0e30c56f","added_by":"auto","created_at":"2026-05-14 08:45:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":538264,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9492264/v1/36ec2a9d-5df8-41c0-a595-3fdbc9e9c22d.pdf"},{"id":108838585,"identity":"f2c99ced-66f3-44df-9e64-4ca6059ac9a2","added_by":"auto","created_at":"2026-05-09 00:37:51","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":326118,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptHarumatsuacceptance2026.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9492264/v1/3fde72304ed032851b48c77e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Anatomical location of small bowel atresia independently predicts preterm delivery: A two-center study in southern Japan","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSmall bowel atresia presents with variable clinical features depending on the anatomical location. Despite advances in neonatal care, this condition remains associated with significant morbidity, particularly short bowel syndrome and feeding difficulties [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe anatomical location of intestinal atresia may influence perinatal outcomes, including delivery timing. The currently accepted vascular accident theory, first confirmed by Louw and Barnard, is supported by various clinical presentations, ranging from isolated atresia to extremely rare cases of near-complete jejunoileal absence [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, the precise relationship between atresia location and gestational age at delivery has not been thoroughly investigated as a continuous variable.\u003c/p\u003e \u003cp\u003eAdvances in prenatal ultrasonography have improved the diagnostic accuracy of small bowel atresia [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, whether these prenatal findings can predict delivery timing and facilitate appropriate perinatal management planning remains unclear.\u003c/p\u003e \u003cp\u003eThis study aimed to investigate the relationship between the anatomical location of small bowel atresia and preterm delivery and identify independent predictors of preterm birth in this patient population.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.1. Study design and patient population\u003c/h2\u003e \u003cp\u003eThis was a retrospective observational study of patients with small-bowel atresia who underwent surgical treatment at two institutions (Kagoshima University Hospital and Kagoshima City Hospital) between April 2000 and March 2024.\u003c/p\u003e \u003cp\u003eInclusion criteria were all consecutive patients with surgically confirmed small bowel atresia (jejunal or ileal atresia) during the study period. Patients with duodenal atresia or colonic atresia were not included in this study. There were no other specific exclusion criteria.\u003c/p\u003e \u003cp\u003eA total of 58 patients with small-bowel atresia were enrolled. Patients were classified into two groups based on gestational age at delivery: preterm (\u0026lt;\u0026thinsp;37 weeks, n\u0026thinsp;=\u0026thinsp;28) and term (\u0026ge;\u0026thinsp;37 weeks, n\u0026thinsp;=\u0026thinsp;30). The patients were further categorized based on the anatomical location of the atresia relative to the ligament of Treitz. Cases of multiple atresia were classified according to the most proximal atretic site.\u003c/p\u003e \u003cp\u003eThe mode of delivery was determined by obstetricians based on maternal and fetal indications. Cesarean section was performed for standard obstetric indications including non-reassuring fetal status, breech presentation, and other maternal or fetal complications. The diagnosis of small bowel atresia itself was not considered an absolute indication for cesarean delivery.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e1.2. Definition of jejunal and ileal atresia\u003c/h2\u003e \u003cp\u003eThe small bowel is anatomically divided into jejunum and ileum based on the total length of the small intestine [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Jejunal atresia was defined as atresia located within the proximal two-fifths of the total small-bowel length from the ligament of Treitz. Ileal atresia was defined as atresia located in the distal three-fifths of the small bowel.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e1.3. Data collection\u003c/h2\u003e \u003cp\u003ePatient demographics, prenatal findings, delivery characteristics, anatomical characteristics of intestinal atresia, surgical procedures, and short-term outcomes were collected from the medical records. Prenatal findings included the prenatal diagnosis status, gestational age at the diagnosis, polyhydramnios, bowel dilatation on ultrasonography, and fetal ascites. Anatomical characteristics included the distance from the ligament of Treitz to the atresia site and classification as jejunal or ileal atresia. Surgical data included the age at surgery, type of surgical procedure performed (primary anastomosis, stoma creation, or membrane excision), and in-hospital mortality.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e1.4. Surgical management\u003c/h2\u003e \u003cp\u003eAll patients underwent surgical intervention for small-bowel atresia. The surgical approach was determined based on the anatomical characteristics of atresia, bowel condition, and overall clinical status. Primary anastomosis was performed when the bowel ends were viable with adequate blood supply and the luminal diameter discrepancy was manageable. Stoma creation was selected in cases of multiple atresia, questionable bowel viability, severe contamination, or extremely low birth weight. Membrane excision was performed for type I atresia with a membranous obstruction.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e1.5. Statistical analyses\u003c/h2\u003e \u003cp\u003eContinuous variables were expressed as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) or median with interquartile range (IQR), as appropriate. Categorical variables are presented as numbers and percentages. Comparisons between the preterm and term groups were performed using the Mann-Whitney U test for continuous variables with non-normal distribution, Student's t-test for normally distributed continuous variables, and Fisher's exact test or chi-square test for categorical variables.\u003c/p\u003e \u003cp\u003eUnivariable and multivariable logistic regression analyses were performed to identify independent predictors of preterm delivery. Variables with \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.1 in the univariate analysis were included in the multivariable model. Results are expressed as odds ratios (ORs) with 95% confidence intervals (CIs). The correlation between the distance from the ligament of Treitz and birth weight was evaluated using the Spearman's rank correlation coefficient.\u003c/p\u003e \u003cp\u003eFor the dose-response analysis, patients were divided into three gestational age groups: early preterm (\u0026lt;\u0026thinsp;34 weeks), late preterm (34\u0026ndash;36 weeks), and term (\u0026ge;\u0026thinsp;37 weeks). The Kruskal-Wallis test was used for overall comparison among the three groups, followed by post-hoc pairwise comparisons using Dunn's test with Bonferroni correction.\u003c/p\u003e \u003cp\u003eAll statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), a graphical user interface for R (R Foundation for Statistical Computing, Vienna, Austria). More precisely, it is a modified version of the R commander designed to add statistical functions frequently used in biostatistics [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Statistical significance was set at \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05. All tests were two sided.\u003c/p\u003e \u003c/div\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003e1.6. Ethical approval\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA retrospective chart review and data collection were performed after institutional review board approval was received in accordance with the Ethical Guidelines for Medical and Health Research Involving Human Subjects by the Ministry of Health, Labor, and Welfare of Japan in 2014. This study complied with the 1964 Declaration of Helsinki (revised in 2013) and was approved by the Research Ethics Committee of Kagoshima University Hospital (registration number: 210329). All participants and their parents provided informed consent for registration in this study.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.1. Patient characteristics\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The clinical characteristics of the preterm and term groups are presented in Table 1. The preterm group had a significantly lower birth weight than the term group (1988 ± 731 g vs. 3062 ± 395 g, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). Male sex was significantly less common in the preterm group than in the term group (25.0% vs. 70.0%, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003eRegarding prenatal findings, prenatal diagnoses were made more frequently in the preterm group than in the term group (85.7% vs. 60.0%, \u003cem\u003ep\u003c/em\u003e = 0.040). The gestational age at the diagnosis in patients with a prenatal diagnosis was significantly earlier in the preterm group (29.0 ± 4.1 weeks vs. 32.5 ± 4.1 weeks, \u003cem\u003ep\u003c/em\u003e = 0.011). Polyhydramnios was more frequently\u0026nbsp;observed in the preterm group (42.9% vs. 13.3%,\u0026nbsp;\u003cem\u003ep\u003c/em\u003e = 0.018). Bowel dilatation on ultrasonography was also detected more frequently in the preterm group (78.5% vs. 50.0%, \u003cem\u003ep\u003c/em\u003e = 0.031). There was no significant difference in\u0026nbsp;the incidence of fetal ascites between the two groups (10.7% vs. 6.7%,\u0026nbsp;\u003cem\u003ep\u003c/em\u003e = 0.67).\u003c/p\u003e\n\u003cp\u003eCesarean delivery was performed significantly more frequently in the preterm group than in the term group (46.4% vs. 13.3%, \u003cem\u003ep\u003c/em\u003e = 0.009). The incidence of umbilical cord ulcers did not differ between groups (3.6% vs. 3.3%, \u003cem\u003ep\u003c/em\u003e = 1.000).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.2. Anatomical characteristics of intestinal atresia\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The anatomical characteristics stratified by gestational age at delivery are shown in Table 2. The distance from the ligament of Treitz to the atresia site was significantly shorter in the preterm group compared to the term group (mean: 31.6 ± 31.5 cm vs. 103.6 ± 39.9 cm, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001; median: 18 cm [IQR 5.0–57.5] vs. 100 cm [IQR 80.25–126.5]).\u003c/p\u003e\n\u003cp\u003eRegarding anatomical classification, jejunal atresia was significantly more common in the preterm group (71.4% vs. 6.7%, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001), while ileal atresia was predominant in the term group (28.6% vs. 93.3%).\u003c/p\u003e\n\u003cp\u003eThe Spearman correlation coefficient between the distance from the ligament of Treitz and birth weight was 0.63 (\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001), indicating a strong positive correlation. As illustrated in Figure 1, proximal atresia was associated with lower birth weight.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.3. Multivariable analysis for preterm delivery\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The results of the logistic regression analysis are presented in Table 3. In the univariate analysis, the distance from the ligament of Treitz (per 10 cm increase) was significantly associated with reduced odds of preterm delivery (crude OR 0.78, 95% CI 0.65–0.94; \u003cem\u003ep\u003c/em\u003e = 0.009). Polyhydramnios was also associated with increased odds of preterm delivery (crude OR 4.74, 95% CI 1.18–23.74, \u003cem\u003ep\u003c/em\u003e = 0.018).\u003c/p\u003e\n\u003cp\u003eIn the multivariable analysis adjusted for both variables, the distance from the ligament of Treitz remained an independent predictor of preterm delivery (adjusted OR 0.79, 95% CI 0.65–0.96, \u003cem\u003ep\u003c/em\u003e = 0.018). This OR of 0.79 indicates that each 10 cm increase in the distance from the ligament of Treitz is associated with an approximately 21% reduction in the odds of preterm delivery, meaning that proximal atresia substantially elevates preterm birth risk in a dose-dependent manner. However, the association between polyhydramnios and preterm delivery was not significant after adjustment (adjusted OR 1.33, 95% CI 0.19–9.46, \u003cem\u003ep\u003c/em\u003e = 0.774).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.4. Surgical procedures and short-term outcomes\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Table 4 presents the surgical and clinical outcomes of the patients. The median age at operation did not differ significantly between the groups (1 day [IQR 0–2.25] in the preterm group vs. 1 day [IQR 1–2.0] in the term group, \u003cem\u003ep\u003c/em\u003e = 0.310).\u003c/p\u003e\n\u003cp\u003eThe distribution of surgical procedures differed significantly between the two groups (\u003cem\u003ep\u003c/em\u003e = 0.0024). Primary anastomosis was performed in 53.6% and 90.0% of the\u0026nbsp;preterm and term groups, respectively. Stoma creation was required in 25.0%\u0026nbsp;and 10.0% of the\u0026nbsp;preterm and term groups, respectively. Membrane excision was performed exclusively in the preterm group (21.4% vs\u0026nbsp;0%).\u003c/p\u003e\n\u003cp\u003eIn-hospital mortality occurred in 2 patients (3.4%) in the preterm group (9.5% vs. 0%, \u003cem\u003ep\u003c/em\u003e = 0.229). Both deaths were associated with short bowel syndrome caused by multiple intestinal atresia in one case and intrauterine midgut volvulus in the other.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.5. Dose-response relationship across gestational age groups\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Figure 2 illustrates the dose-response relationship by comparing the three gestational age groups. The Kruskal-Wallis test showed significant differences among the three groups (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). A post-hoc analysis using Dunn's test with Bonferroni correction revealed significant differences between the early preterm and term groups (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001), and between the late preterm and term groups (\u003cem\u003ep\u003c/em\u003e = 0.005). However, no significant difference was observed between the early and late preterm groups (\u003cem\u003ep\u003c/em\u003e = 0.22).\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn the present study, we retrospectively reviewed our two institutions' experiences with patients with small bowel atresia and investigated the relationship between the anatomical location of atresia and preterm delivery to identify independent predictors of preterm birth. The major findings of this study were as follows: (1) the distance from the ligament of Treitz to the atresia site was an independent predictor of preterm delivery in the multivariable analysis; (2) polyhydramnios showed a significant association with preterm delivery in the univariate analysis but became non-significant after adjusting for the atresia location; (3) a dose-response relationship was observed across\u0026nbsp;the three gestational age groups, with progressively shorter distances from the ligament of Treitz in the earlier gestational age groups; (4)\u0026nbsp;a strong positive correlation was found between the distance from the ligament of Treitz and birth weight.\u003c/p\u003e\n\u003cp\u003eThis study demonstrated that the anatomical location of small bowel atresia, measured as the distance from the ligament of Treitz, is an independent predictor of preterm delivery. These findings have several important clinical implications. First, prenatal identification of the atresia location could serve as a prognostic marker for the preterm delivery risk, allowing clinicians to implement appropriate monitoring and prepare for premature birth. Second, our results indicate that the relationship between the atresia location and gestational age is continuous rather than categorical, indicating that even small differences in the atresia location may influence the timing of delivery.\u003c/p\u003e\n\u003cp\u003eOur analysis revealed that polyhydramnios was not significant after adjusting for atresia location. This statistical finding suggests that polyhydramnios is not an independent cause of preterm delivery but rather a consequence of proximal obstruction. This distinction is clinically meaningful because it implies that treating polyhydramnios alone may not effectively reduce preterm delivery risk unless underlying mechanical obstruction is addressed. The fundamental driver of preterm birth appears to be the anatomical position of atresia. \u0026nbsp;Nakamura et al. demonstrated that elevated bile acid concentrations in the amniotic fluid (≥10 μmol/L) were strongly associated with umbilical cord ulcers and intrauterine fetal death in intestinal atresia [8]. Recent histological studies have supported this hypothesis. Garg et al. demonstrated that light microscopy failed to detect major abnormalities in the proximal dilated bowel in 84% of jejunoileal atresia cases, contradicting previous reports of extensive histological damage. They concluded that bowel plication rather than massive resection should be preferred, as the dilated bowel retains its structural integrity [9].\u003c/p\u003e\n\u003cp\u003eThe dose-response relationship we observed strengthens the causal inference between proximal atresia and preterm delivery. When patients were stratified into three gestational age groups, the distance from the ligament of Treitz showed a progressive stepwise pattern. This gradient effect supports a biological mechanism rather than a mere association, suggesting that the degree of fetal swallowing impairment increases proportionally with the proximity of the obstruction.\u003c/p\u003e\n\u003cp\u003ePrevious studies have documented an association between jejunal atresia and adverse perinatal outcomes. Vecchia et al. reported that jejunal atresia was associated with higher complication rates and poorer long-term outcomes than more distal lesions [1]. Fung et al. found that the distance from the ligament of Treitz was significantly shorter in preterm infants [10]. However, their analysis primarily used categorical comparisons rather than examining distance as a continuous variable in a dose-response analysis.\u003c/p\u003e\n\u003cp\u003eOur study extends these observations by demonstrating a quantitative dose-response relationship using continuous variables, providing more granular prognostic information. Furthermore, our multivariate analysis revealed that polyhydramnios acts as a mediating factor rather than an independent predictor, a distinction not previously reported in the literature. Regarding feeding difficulties, Wang et al. identified several predictors of prolonged time to full enteral nutrition [2], which is relevant because infants with proximal atresia and preterm birth face compounded nutritional risks.\u003c/p\u003e\n\u003cp\u003eOur results have direct implications for prenatal counseling. When a fetal ultrasound examination identifies proximal small-bowel atresia with associated polyhydramnios, obstetricians can estimate preterm delivery risk based on the estimated distance from the ligament of Treitz. This allows for proactive planning, including delivery at tertiary centers with both neonatal intensive care and pediatric surgical expertise. Specifically, prenatal identification of proximal atresia enables consideration of antenatal corticosteroids for fetal lung maturation, enhanced surveillance of amniotic fluid volume and fetal well-being, and early preparation of the neonatal and surgical teams for a complex surgical newborn requiring prompt intervention. Increased fetal surveillance may be warranted in cases of proximal atresia, particularly given the risks highlighted by Nakamura et al. regarding umbilical cord ulceration [8].\u003c/p\u003e\n\u003cp\u003eThe strong correlation between atresia location and birth weight raises the question of whether our findings simply reflect fetal size. However, the distance from the ligament of Treitz remained significant even after adjusting for confounding factors, suggesting that anatomical position exerts an effect independent of fetal size. Biological plausibility supports a causal mechanism whereby proximal obstruction leads to impaired fetal swallowing, which in turn results in polyhydramnios, subsequently causing uterine overdistension, and ultimately triggering preterm labor [11,12].\u003c/p\u003e\n\u003cp\u003eThe combination of proximal atresia and preterm birth may have confounding effects on the long-term outcomes. When combined with a potentially shorter residual bowel length after surgical correction, these patients face elevated risks of short bowel syndrome and intestinal failure. In our series, both deaths occurred in the preterm group and were attributable to short bowel syndrome resulting from multiple intestinal atresia and intrauterine midgut volvuli. As emphasized by Fung et al., bowel length preservation is paramount [10].\u003c/p\u003e"},{"header":"Limitations","content":"\u003cp\u003eThis study had several limitations. First, the retrospective design limits causal inferences. Second, the relatively small sample sizes of the two institutions may limit generalizability. Third, we observed an unexpected higher proportion of female infants in the preterm group (75.0% vs. 30.0%), which contradicts the generally recognized male predominance in preterm births. This finding may reflect the small sample size and possible selection bias in our cohort. The relationship between proximal intestinal atresia and sex distribution has not been previously reported and warrants further investigation in larger studies. Fourth, the long-term outcomes, including neurodevelopmental status, were not evaluated. Future prospective multicenter studies with larger cohorts are needed to validate our findings and to develop clinical prediction models. Finally, the retrospective design precluded systematic distinction between spontaneous and iatrogenic preterm delivery; confounding by obstetric decision-making, such as elective early delivery for maternal or fetal indications unrelated to the atresia itself, cannot be entirely excluded. Future prospective studies should systematically record the indication for delivery to allow for this distinction.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThis study demonstrated that proximal small bowel atresia, measured by the distance from the ligament of Treitz, is an independent predictor of preterm delivery. Polyhydramnios acts as a mediating factor rather than an independent cause. The dose-response relationship observed across gestational age groups strengthens the evidence for causality. Prenatal identification of the atresia location may facilitate appropriate perinatal management and parental counseling, enabling delivery planning at tertiary centers equipped with neonatal intensive care and pediatric surgical expertise. Future prospective studies are warranted to validate these findings and develop clinical prediction models.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eT.H., A.N., and K.S. wrote the manuscript. S.O. and K.Y. prepared the tables and reviewed the literature. Y.T., Y.T., N.N., and C.K. collected data based on medical records, and A.Y., H.O., T.K., E.H., T.K., M.T., and T.T. provided conceptual advice. S.I. critically reviewed the manuscript and supervised the data-collection process. All authors have reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflicts of interest in association with the present study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Mr. Brian Quinn for his comments and assistance with this manuscript. This study was supported by a research grant from The Mother and Child Health Foundation, a research grant from the Kawano Masanori Memorial Public Interest Incorporated Foundation for Promotion of Pediatrics, and Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS: 25K22713, 25K11062, 25K11154, 25K11847, 25K11871, 24K06285, 24K15813, 23K20735, 23K07281,\u0026nbsp;23K08031, 23K08052, 23K11934).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr clear=\"all\"\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDalla Vecchia LK, Grosfeld JL, West KW, Rescorla FJ, Scherer LR, Engum SA (1998) Intestinal atresia and stenosis: a 25-year experience with 277 cases. Arch Surg 133(5):490\u0026ndash;496 discussion 496\u0026ndash;497\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang J, Du L, Cai W, Pan W, Yan W (2014) Prolonged feeding difficulties after surgical correction of intestinal atresia: a 13-year experience. J Pediatr Surg 49(11):1593\u0026ndash;1597\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTripathy PK, Ray BK, Mohanty HK (2017) Congenital absence of jejunum and ileum: A case report and literature review. Afr J Paediatr Surg 14(3):53\u0026ndash;55\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJu H, Feng S, Huang Y (2022) Diagnostic value of the microcolon using ultrasonography in small bowel atresia. BMC Pediatr 22(1):576\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHao J, Zhang Y, Tianyu L, Bo S, Shu F, Feng S, Chao J, Ying H (2019) Preliminary Investigation of the Diagnosis of Neonatal Congenital Small Bowel Atresia by Ultrasound. Biomed Res Int 2019:7097159\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVinit N, Mitanchez D, Lemale J, Garel C, Jouannic JM, Hervieux E, Audry G, Irtan S (2021) How can we improve perinatal care in isolated multiple intestinal atresia? A retrospective study with a 30-year literature review. Arch Pediatr 28(3):226\u0026ndash;233\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKanda Y (2013) Investigation of the freely available easy-to-use software 'EZR' for medical statistics. Bone Marrow Transpl 48(3):452\u0026ndash;458\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNakamura N, Ozawa K, Wada S, Matsuoka K, Yoshioka T, Sugibayashi R, Sago H (2019) Umbilical Cord Ulcer and Intrauterine Death in Fetal Intestinal Atresia. Fetal Diagn Ther 46(5):313\u0026ndash;318\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarg V, Puri A, Sakhuja P (2020) Novel insights into the histology of jejunoileal atresia and its therapeutic implications. J Pediatr Surg 55(12):2630\u0026ndash;2634\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFung ACH, Lee MK, Lui MPK, Lip LY, Chung PHY, Wong KKY (2023) Primary anastomosis is the preferred surgical approach for proximal intestinal atresia: a retrospective 20-year analysis. Pediatr Surg Int 39(1):99\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRubio EI, Blask AR, Badillo AT, Bulas DI (2017) Prenatal magnetic resonance and ultrasonographic findings in small-bowel obstruction: imaging clues and postnatal outcomes. Pediatr Radiol 47(4):411\u0026ndash;421\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohn R, D'Antonio F, Khalil A, Bradley S, Giuliani S (2015) Diagnostic Accuracy of Prenatal Ultrasound in Identifying Jejunal and Ileal Atresia. Fetal Diagn Ther 38(2):142\u0026ndash;146\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":" \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 \u003cdiv class=\"SimplePara\"\u003ePatient characteristics and perinatal findings stratified by gestational age at delivery\u003c/div\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=\"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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCharacteristic\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eOverall (n\u0026thinsp;=\u0026thinsp;58)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003ePreterm (n\u0026thinsp;=\u0026thinsp;28)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eTerm (n\u0026thinsp;=\u0026thinsp;30)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003ep\u003c/span\u003e value\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003eOR (95% CI)\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003ePatient demographics\u003c/div\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\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eBirth weight (g), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e2571\u0026thinsp;\u0026plusmn;\u0026thinsp;778\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e1988\u0026thinsp;\u0026plusmn;\u0026thinsp;731\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e3062\u0026thinsp;\u0026plusmn;\u0026thinsp;395\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026lt;\u0026thinsp;0.001\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eMale gender, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e28 (48.3)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e7 (25.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e21 (70.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026lt;\u0026thinsp;0.001\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.14 (0.03\u0026ndash;0.52)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003ePrenatal findings\u003c/span\u003e\u003c/div\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003ePrenatal diagnosis, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e42 (72.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e24 (85.7)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e18 (60.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.040\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e3.9 (0.97\u0026ndash;19.44)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eGestational age at diagnosis (weeks), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e31.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e29.0\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e32.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.011\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003e-\u003c/span\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003ePolyhydramnios, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e16 (27.6)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e12 (42.9)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e4 (13.3)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.018\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e4.74 (1.18\u0026ndash;23.74)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eBowel dilatation on ultrasound, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e37 (63.8)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e22 (78.5)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e15 (50.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.031\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e3.58 (1.02\u0026ndash;14.05)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eFetal ascites, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e5 (8.6)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e3 (10.7)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e2 (6.7)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.67\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e1.67 (0.18\u0026ndash;21.45)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003eDelivery characteristics\u003c/span\u003e\u003c/div\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCesarean delivery, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e17 (29.3)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e13 (46.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e4 (13.3)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.009\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e5.46 (1.37\u0026ndash;27.27)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eUmbilical cord ulcer, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e2 (3.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e1 (3.6)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e1 (3.3)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e1.000\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e1.07 (0.01\u0026ndash;87.12)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eOR, odds ratio; CI, confidence interval; SD, standard deviation.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\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 \u003cdiv class=\"SimplePara\"\u003eAnatomical characteristics of intestinal atresia and correlation with gestational age at delivery\u003c/div\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=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCharacteristic\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eOverall (n\u0026thinsp;=\u0026thinsp;58)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003ePreterm (n\u0026thinsp;=\u0026thinsp;28)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eTerm (n\u0026thinsp;=\u0026thinsp;30)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003ep\u003c/span\u003e value\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eLocation of atresia\u003c/div\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\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eDistance from Treitz ligament (cm), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e67.3\u0026thinsp;\u0026plusmn;\u0026thinsp;45.2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e31.6\u0026thinsp;\u0026plusmn;\u0026thinsp;31.5\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e103.6\u0026thinsp;\u0026plusmn;\u0026thinsp;39.9\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026lt;\u0026thinsp;0.001\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eDistance from Treitz (cm), median (IQR)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e60.0 (9.5-91.75)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e18 (5.0-57.5)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e100 (80.25\u0026ndash;126.5)\u003c/div\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 \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003eAnatomical classification\u003c/span\u003e\u003c/div\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eJejunal atresia, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e22 (37.9)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e20 (71.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e2 (6.7)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026lt;\u0026thinsp;0.001\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eIleal atresia, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e36 (62.1)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e8 (28.6)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e28 (93.3)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003eCorrelation with birth weight\u003c/span\u003e\u003c/div\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eSpearman correlation coefficient\u003c/div\u003e \u003cdiv class=\"SimplePara\"\u003e(TL distance vs birth weight)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003er\u0026thinsp;=\u0026thinsp;0.63\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u0026lt;\u0026thinsp;0.001\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*Per 10 cm increase in distance from ligament of Treitz\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eSD, standard deviation; IQR, interquartile range; TL, Treitz ligament.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\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 \u003cdiv class=\"SimplePara\"\u003eMultivariable logistic regression analysis for preterm delivery: parsimonious model accounting for sample size constraints\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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 \u003cdiv align=\"char\" char=\".\" 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=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cdiv class=\"SimplePara\"\u003eVariable\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eUnivariate analysis\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eMultivariable analysis\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eCrude OR\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e95% CI\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003ep\u003c/span\u003e value\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eAdjusted OR*\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e95% CI\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003ep\u003c/span\u003e value\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eDistance from Treitz ligament (per 10 cm)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.78\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.65\u0026ndash;0.94\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.009\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.79\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.65\u0026ndash;0.96\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.018\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003ePolyhydramnios (present vs absent)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e4.74\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e1.18\u0026ndash;23.74\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.018\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e1.33\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.19\u0026ndash;9.46\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.774\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eOR, odds ratio; CI, confidence interval.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\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 \u003cdiv class=\"SimplePara\"\u003eSurgical procedures and short-term outcomes stratified by gestational age at delivery\u003c/div\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 \u003cdiv class=\"SimplePara\"\u003eOutcome\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eOverall\u003c/div\u003e \u003cdiv class=\"SimplePara\"\u003e(n\u0026thinsp;=\u0026thinsp;58)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003ePreterm\u0026thinsp;\u0026lt;\u0026thinsp;37 weeks (n\u0026thinsp;=\u0026thinsp;28)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eTerm\u0026thinsp;\u0026ge;\u0026thinsp;37 weeks (n\u0026thinsp;=\u0026thinsp;30)\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Italic\" class=\"Italic\" name=\"Emphasis\"\u003eP\u003c/span\u003e value\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eSurgical characteristics\u003c/div\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\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eAge at operation (days), median (IQR)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e1 (0\u0026ndash;2)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e1 (0-2.25)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e1 (1\u0026ndash;2.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.310\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003eSurgical procedure, n (%)\u003c/span\u003e\u003c/div\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 \u003cdiv class=\"SimplePara\"\u003e0.0024\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e- Primary anastomosis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e42 (72.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e15 (53.6)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e27 (90.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e- Stoma creation\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e10 (17.2)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e7 (25.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e3 (10.0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e- Membrane excision\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e6 (10.3)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e6 (21.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e0 (0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e-\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e\u003cspan type=\"Bold\" class=\"Bold\" name=\"Emphasis\"\u003eClinical outcomes\u003c/span\u003e\u003c/div\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 \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eIn-hospital mortality, n (%)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e2 (3.4)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e2 (9.5)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003e0 (0)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.229\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eIQR, interquartile Range.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\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":"pediatric-surgery-international","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pesi","sideBox":"Learn more about [Pediatric Surgery International](http://link.springer.com/journal/383)","snPcode":"383","submissionUrl":"https://submission.nature.com/new-submission/383/3","title":"Pediatric Surgery International","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Small bowel atresia, Preterm delivery, Jejunal atresia, Polyhydramnios, Prenatal diagnosis","lastPublishedDoi":"10.21203/rs.3.rs-9492264/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9492264/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003ePurpose\u003c/b\u003e\u003c/p\u003e \u003cp\u003eSmall bowel atresia (SBA) presents with variable clinical features depending on anatomical location. We investigated the relationship between atresia location and preterm delivery.\u003c/p\u003e\u003cp\u003e\u003cb\u003eMethods\u003c/b\u003e\u003c/p\u003e \u003cp\u003e We retrospectively reviewed 58 patients who underwent surgery for SBA at two institutions between April 2000 and March 2024. Patients were divided into preterm (\u0026lt;\u0026thinsp;37 weeks, n\u0026thinsp;=\u0026thinsp;28) and term (\u0026ge;\u0026thinsp;37 weeks, n\u0026thinsp;=\u0026thinsp;30) groups. Clinical characteristics, prenatal findings, anatomical location, and surgical outcomes were compared. A logistic regression analysis identified independent predictors of preterm delivery.\u003c/p\u003e\u003cp\u003e\u003cb\u003eResults\u003c/b\u003e\u003c/p\u003e \u003cp\u003ePreterm infants showed lower birth weight (1988\u0026thinsp;\u0026plusmn;\u0026thinsp;731 g vs. 3062\u0026thinsp;\u0026plusmn;\u0026thinsp;395 g, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and higher rates of prenatal diagnosis (85.7% vs. 60.0%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.040), polyhydramnios (42.9% vs. 13.3%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.018), and bowel dilatation (78.5% vs. 50.0%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.031). The distance from the ligament of Treitz was shorter in preterm infants (31.6\u0026thinsp;\u0026plusmn;\u0026thinsp;31.5 cm vs. 103.6\u0026thinsp;\u0026plusmn;\u0026thinsp;39.9 cm, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Jejunal atresia was more common in preterm infants (71.4% vs. 6.7%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). A strong correlation was observed between birth weight and atresia distance (r\u0026thinsp;=\u0026thinsp;0.63, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In a multivariable analysis, proximal atresia was an independent predictor of preterm delivery (adjusted OR 0.79 per 10 cm, 95% CI 0.65\u0026ndash;0.96, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.018).\u003c/p\u003e\u003cp\u003e\u003cb\u003eConclusion\u003c/b\u003e\u003c/p\u003e \u003cp\u003eProximal SBA was independently associated with preterm delivery. Prenatal identification may facilitate appropriate perinatal management and parental counseling.\u003c/p\u003e","manuscriptTitle":"Anatomical location of small bowel atresia independently predicts preterm delivery: A two-center study in southern Japan","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-09 00:37:47","doi":"10.21203/rs.3.rs-9492264/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-04-26T15:16:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"340165079514415562491512844803786995236","date":"2026-04-26T15:15:34+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-24T14:37:14+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-24T14:36:32+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-24T06:31:10+00:00","index":"","fulltext":""},{"type":"submitted","content":"Pediatric Surgery International","date":"2026-04-22T06:52:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"pediatric-surgery-international","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pesi","sideBox":"Learn more about [Pediatric Surgery International](http://link.springer.com/journal/383)","snPcode":"383","submissionUrl":"https://submission.nature.com/new-submission/383/3","title":"Pediatric Surgery International","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"69b337b1-eb5a-49e4-b6a0-7405a85544ef","owner":[],"postedDate":"May 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-09T00:37:47+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-09 00:37:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9492264","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9492264","identity":"rs-9492264","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}