Results
We screened 27,269 patients for eligibility and included 20,907 patients for analysis ( Figure 1 ). The baseline characteristics of the patients included in this study are listed in Table 1 . Of these pregnancies, 18,428 (88.1%) pregnancies were unaffected by either HDP or GDM, 872 (4.1%) were complicated by HDP, and 1715 (8.2%) pregnancies were complicated by GDM. Both HDP and GDM were present in 108 pregnancies (0.5%). Patients in the unaffected group were younger than those in the HDP group and the GDM group. Patients in the unaffected group also had a lower BMI than patients in the HDP, GDM and HDP/GDM groups. Both systolic and diastolic blood pressures were higher in the HDP and HDP/GDM groups than in the unaffected group. Blood glucose levels were higher in the HDP, GDM, and HDP/GDM groups compared to the unaffected group. The GDM and HDP/GDM groups had greater numbers of retrieved oocytes than the unaffected group, while the unaffected and GDM groups had lower proportions of single embryo transfer compared to the HDP group. The majority of women in all groups underwent blastocyst embryo transfer: unaffected (71.4%), HDP (76.8%), GDM (72.0%), and HDP/GDM (75.9%). Figure 1 Flow diagram of participant screening and enrollment. IVF, in vitro fertilization; ICSI, intracytoplasmic sperm injection; PCOS, polycystic ovary syndrome. Figure 1 Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025 Table 1 Basic characteristics of the participants across different groups Table 1 Unaffected HDP alone GDM alone HDP/GDM P value N (%) N=18428 (88.1%) N=872 (4.1%) N=1715 (8.2%) N=108 (0.5%) Age (years) a , b , e 30 (28-33) 31 (28-34) 31 (29-34) 31.5 (28-34.75) <.001 BMI (kg/m²) a , b , c , d , f 22.58 (20.61-25.08) 24.50 (22.10-27.34) 24.03 (21.57-26.64) 26.53 (23.44-28.64) <.001 Gravidity ≥ 1, n (%) * 8743 (47.5%) 400 (45.9%) 829 (48.3%) 52 (48.1%) .698 Parity ≥ 1, n (%) * 4385 (23.8%) 176 (20.2%) 381 (22.2%) 26 (24.1%) .049 Systolic pressure (mmHg) a , c , e , f 114 (106-123) 123 (114-130) 116 (107-124) 120 (112-129) <.001 Diastolic pressure (mmHg) a , b , c , e , f 68 (62-74) 74 (67-80) 69 (63-76) 74 (66-79.75) <.001 Glucose (mmol/L) a , b , c , d , e 5.2 (4.93-5.48) 5.29 (5-5.58) 5.39 (5.08-5.68) 5.425 (5.13-5.69) <.001 Infertility causes, n (%) * <.001 Tubal factors 10403 (56.5%) 471 (54.1%) 965 (56.3%) 68 (63.0%) Endometriosis 588 (3.2%) 18 (2.1%) 49 (2.9%) 2 (1.9%) Uterine factors 93 (0.5%) 8 (0.9%) 11 (0.6%) 0 Male factor b 2812 (15.3%) 110 (12.6%) 218 (12.7%) 7 (6.5%) Other factors 208 (1.1%) 13 (1.5%) 21 (1.2%) 2 (1.9%) Mixed factors a 4311 (23.4%) 250 (28.7%) 449 (26.2%) 29 (26.9%) Number of oocytes retrieved b , c , e 3 (2-4) 3 (2-4) 3 (3-4) 3 (3-4) <.001 Donor sperm, n (%) 1217 (6.6%) 56 (6.4%) 108 (6.3%) 10 (9.3%) .674 Fertilization methods, n (%) .052 IVF 13604 (73.8%) 631 (72.4%) 1288 (75.1) 83 (76.9%) ICSI 4123 (22.4%) 201 (23.1%) 357 (20.8%) 16 (14.8%) Half IVF and half ICSI 701 (3.8%) 40 (4.6%) 70 (4.1%) 9 (8.3%) Endometrial thickness before embryo transfer (mm) a , * 10 (9.0-12.0) 10 (8.5-11.0) 10 (8.5-11.0) 10 (9.0-11.0) <.001 Stage of embryo transferred, n (%) .005 Cleavage-stage embryo a 5265 (28.6%) 202 (23.2%) 480 (28%) 26 (24.1%) Blastocyst embryo a 13163 (71.4%) 670 (76.8%) 1235 (72.0%) 82 (75.9%) Number of embryos transferred, n (%) a , e .005 1 13254 (71.9%) 674 (77.3%) 1231 (71.8%) 82 (75.9%) 2 5174 (28.1%) 198 (22.7%) 484 (28.2%) 26 (24.1%) Year of treatment, n (%) <.001 2015-2016 b , e 6863 (37.2%) 331 (38.0%) 457 (26.6%) 29 (26.9%) 2017-2018 6485 (35.2%) 298 (34.2%) 606 (35.3%) 37 (34.3%) 2019-2021 b , e 5080 (27.6%) 243 (27.9%) 652 (38.0%) 42 (38.9%) GDM, gestational diabetes mellitus; HDP, hypertensive disorders of pregnancy; BMI , body mass index; IVF, in vitro fertilization; ICSI , intracytoplasmic sperm injection. a P<. 001 for the comparison between the unaffected group and the HDP group b P<. 001 for the comparison between the unaffected group and the GDM group c P <.001 for the comparison between the unaffected group and the HDP/GDMgroup d P <.001 for the comparison between the HDP group and the HDP/GDM group e P<. 001 for the comparison between the HDP and GDM groups f P<. 001 for the comparison between the HDP/GDM and GDM groups ⁎ Gravidity of 4 patients and parity of 4 patients in the unaffected group were missing. *Endometrial thickness of 43 patients in the unaffected group, 7 patients in the GDM group and 1 patient in the HDP group was missing. *Infertility causes of 13 patients in the unaffected group, 2 patients in the GDM group and 2 patients in the HDP group were missing. Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025
Flow diagram of participant screening and enrollment.
IVF, in vitro fertilization; ICSI, intracytoplasmic sperm injection; PCOS, polycystic ovary syndrome.
Basic characteristics of the participants across different groups
GDM, gestational diabetes mellitus; HDP, hypertensive disorders of pregnancy; BMI , body mass index; IVF, in vitro fertilization; ICSI , intracytoplasmic sperm injection.
P<. 001 for the comparison between the unaffected group and the HDP group
P<. 001 for the comparison between the unaffected group and the GDM group
P <.001 for the comparison between the unaffected group and the HDP/GDMgroup
P <.001 for the comparison between the HDP group and the HDP/GDM group
P<. 001 for the comparison between the HDP and GDM groups
P<. 001 for the comparison between the HDP/GDM and GDM groups
Gravidity of 4 patients and parity of 4 patients in the unaffected group were missing.
*Endometrial thickness of 43 patients in the unaffected group, 7 patients in the GDM group and 1 patient in the HDP group was missing.
*Infertility causes of 13 patients in the unaffected group, 2 patients in the GDM group and 2 patients in the HDP group were missing.
Table 2 shows a greater birthweight in the unaffected group than in the HDP group (3430 [3150–3723] g vs . 3200 [2690–3600] g, P<. 001) and the HDP/GDM group (3430 [3150–3723] g vs . 3200 [2650–3615] g, P<. 001). The GDM group had a greater birthweight than both the HDP group (3450 [3120–3800] g vs . 3200 [2690–3600] g, P<. 001) and the HDP/GDM group (3450 [3120–3800] g vs . 3200 [2650–3615] g, P<. 001). We observed increased risks of LGA (28.0 vs . 21.1% and P<. 001), macrosomia (12.9% vs . 9.1% and P<. 001), and low birthweight (4.4% vs . 2.8% and P<. 001) in the GDM group compared to the unaffected group. The HDP and HDP/GDM groups had greater risks of SGA (14.4% vs . 3.6% and P<. 001, and 13.9% vs . 3.6%, P<. 001, respectively) and low birthweight (17.6% vs . 2.8% and P<. 001, and 18.5% vs . 2.8% and P<. 001, respectively) than the unaffected group. Table 2 Pregnancy outcome frequencies by exposure group Table 2 Unaffected N = 18428 HDP alone N = 872 GDM alone N = 1715 HDP/GDM N = 108 P value Neonatal outcomes Neonatal gender * .904 Male 9673/18351 (52.7%) 452/864 (52.3%) 911/1712 (53.2%) 60/108 (55.6%) Female 8678/18351 (47.3%) 412/864 (47.7%) 801/1712 (46.8%) 48/108 (44.4%) Birthweight (g) a,c,e,f,# 3430 (3150-3723) 3200 (2690-3600) 3450 (3120-3800) 3200 (2650-3615) <.001 Size for gestational age # Macrosomia b , e 1662/18268 (9.1%) 66/863 (7.6%) 221/1710 (12.9%) 11/108 (10.2%) <.001 Low birthweight a , b , c , e , f 513/18268 (2.8%) 152/863 (17.6%) 76/1710 (4.4%) 20/108 (18.5%) <.001 AGA a , b , c 13748/18268 (75.3%) 586/863 (67.9%) 1159/1710 (67.8%) 67/108 (62.0%) <.001 LGA b , e 3859/18268 (21.1%) 153/863 (17.7%) 479/1710 (28.0%) 26/108 (24.1%) <.001 SGA a , c , e , f 661/18268 (3.6%) 124/863 (14.4%) 72/1710 (4.2%) 15/108 (13.9%) <.001 Obstetric outcomes Preterm delivery a , b , c , e , f 946/18428 (5.1%) 200/872 (22.9%) 163/1715 (9.5%) 25/108 (23.1%) <.001 Post-term delivery 37/18428 (0.2%) 1/872 (0.1%) 1/1715 (0.1%) 0 (0.0%) .536 LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). a P <.001 for the comparison between the unaffected group and the HDP group. b P<. 001 for the comparison between the unaffected group and the GDM group. c P<. 001 for the comparison between the unaffected group and the HDP/GDM group. d P <.001 for the comparison between the HDP group and the HDP/GDM group. e P<. 001 for the comparison between the HDP and GDM groups. f P<. 001 for the comparison between the HDP/GDM and GDM groups. ⁎ Seventy-six patients in the unaffected group, 3 patients in the GDM group, and 8 patients in the HDP group delivered death babies or whose information was missing, and the gender of these babies was not analyzed. # There were 160 patients in the unaffected group, 5 patients in the GDM group, and 9 patients in the HDP group delivered death babies or whose information was missing, and the birthweight of these babies was not analyzed. Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025
Pregnancy outcome frequencies by exposure group
LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive).
P <.001 for the comparison between the unaffected group and the HDP group.
P<. 001 for the comparison between the unaffected group and the GDM group.
P<. 001 for the comparison between the unaffected group and the HDP/GDM group.
d P <.001 for the comparison between the HDP group and the HDP/GDM group.
P<. 001 for the comparison between the HDP and GDM groups.
P<. 001 for the comparison between the HDP/GDM and GDM groups.
Seventy-six patients in the unaffected group, 3 patients in the GDM group, and 8 patients in the HDP group delivered death babies or whose information was missing, and the gender of these babies was not analyzed.
There were 160 patients in the unaffected group, 5 patients in the GDM group, and 9 patients in the HDP group delivered death babies or whose information was missing, and the birthweight of these babies was not analyzed.
The rates of AGA in each exposure group are presented in Table 3 . According to the unadjusted analyses, each of the 3 exposure groups had a lower rate of AGA birthweight than the unaffected groups (HDP: OR: 0.70; 95% CI: [0.60–0.81]; P<. 001; GDM: OR: 0.69; 95% CI: [0.62–0.77]; P<. 001; HDP/GDM: OR: 0.54; 95% CI: [0.36–0.79]; P=. 002). Table 3 Logistic regression analyses of neonatal outcomes. Table 3 Outcome Exposure Unadjusted Adjusted OR (95% CI) P- value aOR (95% CI) P value AGA Unaffected Reference Reference HDP alone 0.70 (0.60,0.81) <.001 0.79 (0.68,0.92) .002 GDM alone 0.69 (0.62,0.77) <.001 0.77 (0.69,0.86) <.001 HDP/GDM 0.54 (0.36,0.79) .002 0.68 (0.46,1.01) .058 SGA Unaffected Reference Reference HDP alone 4.47 (3.64,5.49) <.001 5.67 (4.56,7.04) <.001 GDM alone 1.17 (0.91,1.50) .213 1.34 (1.04,1.72) .023 HDP/GDM 4.29 (2.47,7.45) <.001 6.37 (3.63,11.18) <.001 LGA Unaffected Reference Reference HDP alone 0.80 (0.67,0.96) .017 0.65 (0.54,0.78) <.001 GDM alone 1.45 (1.30,1.62) <.001 1.24 (1.11,1.39) <.001 HDP/GDM 1.18 (0.76,1.84) .455 0.83 (0.53,1.31) .433 Macrosomia Unaffected Reference Reference HDP alone 0.82 (0.64,1.06) .147 0.65 (0.50,0.85) .002 GDM alone 1.48 (1.27,1.72) <.001 1.24 (1.06,1.45) .005 HDP/GDM 1.13 (0.60,2.11) .696 0.76 (0.40,1.44) .416 Low birthweight Unaffected Reference Reference HDP alone 7.39 (6.08,9.00) <.001 7.37 (6.00,9.06) <.001 GDM alone 1.61 (1.25,2.05) <.001 1.55 (1.20,1.99) <.001 HDP/GDM 7.86 (4.80,12.88) <.001 7.77 (4.70,12.84) <.001 LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval. The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred, glucose level, and year of treatment. Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025
Logistic regression analyses of neonatal outcomes.
LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval.
The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred, glucose level, and year of treatment.
In the adjusted analyses, compared with unaffected pregnancies, we observed lower adjusted odds of giving birth to an AGA infant in pregnancies complicated by HDP (aOR: 0.79; 95% CI: [0.68–0.92]; P=. 002) and GDM (aOR: 0.77; 95% CI: [0.69–0.86]; P<. 001) ( Table 3 ). Similarly, the adjusted odds of delivering an AGA infant were reduced for HDP/GDM pregnancies (aOR: 0.68; 95% CI: [0.46–1.01]; P=. 058).
The incidence rates of LGA and SGA in each exposure group are given in Table 2 and Figure 2 . The results examining these birthweight outcomes in the adjusted models are given in Table 3 . Figure 2 SGA and LGA incidence by different exposure group. GDM, gestational diabetes mellitus alone; HDP, hypertensive disorders of pregnancy alone; LGA, large for gestational age; SGA, small for gestational age. Figure 2 Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025
SGA and LGA incidence by different exposure group.
GDM, gestational diabetes mellitus alone; HDP, hypertensive disorders of pregnancy alone; LGA, large for gestational age; SGA, small for gestational age.
According to the unadjusted analyses, HDP pregnancies had a greater risk of SGA than unaffected pregnancies (OR: 4.47; 95% CI: [3.64–5.49]; P<. 001), and this difference was significant in the adjusted analyses (aOR: 5.67; 95% CI: [4.56–7.04]; P<. 001). Both unadjusted and adjusted analyses showed that the risk of low birth weight was greater in the HDP group than in the unaffected group (OR: 7.39; 95% CI: [6.08–9.00]; P<. 001; aOR: 7.37; 95% CI: [6.00–9.06]; P<. 001). HDP was associated with a lower risk of delivering an LGA infant according to the unadjusted (OR: 0.80; 95% CI: [0.67–0.96]; P=. 017) and adjusted (aOR: 0.65; 95% CI: [0.54–0.78]; P<. 001) models ( Table 3 ).
Compared with unaffected pregnancies, GDM-affected pregnancies had greater risks of SGA (aOR: 1.34; 95% CI: [1.04–1.72]; P=. 023) and low birthweight (OR: 1.61; 95% CI: [1.25–2.05]; P<. 001; aOR: 1.55; 95% CI: [1.20–1.99]; P<. 001). GDM-affected pregnancies had a greater risk of LGA in both the unadjusted (OR: 1.45; 95% CI: [1.30–1.62]; P<. 001) and adjusted (aOR: 1.24; 95% CI: [1.11–1.39]; P<. 001) analyses. In addition, women with GDM had a greater risk of macrosomia than the unaffected group in both the unadjusted (OR: 1.48; 95% CI: [1.27–1.72]; P<. 001) and adjusted (aOR: 1.24; 95% CI: [1.06–1.45]; P=. 005) analyses.
Compared with unaffected pregnancies, HDP/GDM-affected pregnancies had a greater risk of SGA (OR: 4.29; 95% CI: [2.47–7.45]; P<. 001) but not LGA (OR: 1.18; 95% CI: [0.76–1.84]; P=. 455) according to unadjusted analyses. After adjustment, the HDP/GDM group had a greater risk of SGA than the unaffected group (aOR: 6.37; 95% CI: [3.63–11.18]; P<. 001), whereas the HDP/GDM group had a similar risk of LGA compared to the unaffected group (aOR: 0.83; 95% CI: [0.53–1.31]; P=. 433). We also observed a greater risk of low birthweight in the HDP/GDM group than in the unaffected group (aOR: 7.77; 95% CI: [4.70–12.84]; P<. 001).
As illustrated in Table 4 , pregnancies affected by HDP (aOR: 4.85; 95% CI: [4.06–5.79]; P<. 001), GDM (aOR: 1.76; 95% CI: [1.47–2.11]; P<. 001), and HDP/GDM (aOR: 4.61; 95% CI: [2.91–7.29]; P<. 001) were associated with greater odds of preterm delivery than unaffected pregnancies. In contrast, HDP-,GDM-, and HDP/GDM-affected pregnancies were not associated with increased odds of post-term delivery (HDP: aOR: 0.52; 95% CI: [0.07–3.88]; P=. 528; GDM: aOR: 0.28; 95% CI: [0.03–2.11]; P=. 221; HDP/GDM: aOR: 0.00; 95% CI: [0.00]; P=. 997). In addition, pregnancies affected by HDP (aOR: 4.75; 95% CI: [3.74–6.01]; P<. 001),GDM (aOR: 1.22; 95% CI: [1.09–1.37]; P<. 001), and HDP/GDM (aOR: 3.64; 95% CI: [1.93–6.85]; P<. 001) were associated with greater odds of cesarean section than were unaffected pregnancies. When analyses were restricted to AGA infants ( Table 4 ), the results were similar to those in the whole population. Table 4 Logistic regression analyses of perinatal outcomes Table 4 All infants Outcome Exposure Unadjusted Adjusted OR (95% CI) P- value aOR (95% CI) P value Preterm delivery Unaffected Reference Reference HDP alone 5.50 (4.63,6.52) <.001 4.85 (4.06,5.79) <.001 GDM alone 1.94 (1.63,2.31) <.001 1.76 (1.47,2.11) <.001 HDP/GDM 5.56 (3.54,8.74) <.001 4.61 (2.91,7.29) <.001 Post-term delivery Unaffected Reference Reference HDP alone 0.57 (0.07,4.16) .58 0.52 (0.07,3.88) .528 GDM alone 0.29 (0.04,2.11) .22 0.28 (0.03,2.11) .221 HDP/GDM 0.00 (0.00) .99 0.00 (0.00) .997 Cesarean section Unaffected Reference Reference HDP alone 5.66 (4.48,7.15) <.001 4.75 (3.74,6.01) <.001 GDM alone 1.43 (1.28,1.59) <.001 1.22 (1.09,1.37) <.001 HDP/GDM 4.97 (2.66,9.29) <.001 3.64 (1.93,6.85) <.001 AGA infants alone Outcome Exposure Unadjusted Adjusted OR (95% CI) P- value aOR (95% CI) P value Preterm delivery Unaffected Reference Reference HDP alone 4.26 (3.42,5.31) <.001 3.47 (2.76,4.36) <.001 GDM alone 1.81 (1.46,2.25) <.001 1.64 (1.32,2.05) <.001 HDP/GDM 3.98 (2.12,7.47) <.001 2.89 (1.53,5.49) .001 Postterm delivery Unaffected Reference Reference HDP alone 0.97 (0.13,7.23) .982 0.88 (0.11,6.72) .907 GDM alone 0.49 (0.06,3.65) .490 0.53 (0.07,4.01) .543 HDP/GDM 0.00 (0.00) .998 0.00 (0.00) .997 Cesarean section Unaffected Reference Reference HDP alone 5.47 (4.19,7.15) <.001 4.59 (3.50,6.03) <.001 GDM alone 1.25 (1.10,1.42) <.001 1.12 (0.98,1.28) .086 HDP/GDM 3.62 (1.85,7.11) <.001 2.65 (1.33,5.26) .005 LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval. The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred,glucose level and year of treatment. Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025
Logistic regression analyses of perinatal outcomes
LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval.
The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred,glucose level and year of treatment.
To compare potential risks of fresh versus frozen embro transfer, we conducted subanalyses among the 4 groups, as shown in Table 5 , Table 6 . Women with HDP who underwent fresh embryo transfer had significantly greater risks of SGA (aOR: 6.32; 95% CI: [4.45–8.97]; P<. 001) and low birthweight (aOR: 7.65; 95% CI: [5.35–10.93]; P<. 001). Similarly, those who underwent frozen embryo transfer also had increased risk of SGA (aOR: 5.60; 95% CI: [4.23–7.41]; P<. 001) and low birthweight (aOR: 7.57; 95% CI: [5.86–9.78]; P<. 001) than those unaffected pregnancies. Table 5 Neonatal and perinatal outcomes by different exposures for fresh embryo transfer Table 5 Outcome Exposure Fresh embryo Unadjusted Adjusted OR (95% CI) P- value aOR (95% CI) P value AGA Unaffected Reference Reference HDP alone 0.50 (0.39,0.65) <.001 0.59 (0.45,0.76) <.001 GDM alone 0.73 (0.61,0.87) <.001 0.82 (0.68,0.98) .031 HDP/GDM 0.28 (0.14,0.57) <.001 0.36 (0.18,0.74) .006 SGA Unaffected Reference Reference HDP alone 4.46 (3.21,6.19) <.001 6.32 (4.45,8.97) <.001 GDM alone 0.74 (0.48,1.14) .184 0.83 (0.53,1.29) .419 HDP/GDM 3.77 (1.44,9.86) .007 6.07 (2.25,16.38) <.001 LGA Unaffected Reference Reference HDP alone 1.07 (0.79,1.44) .636 0.81 (0.60,1.11) .198 GDM alone 1.50 (1.25,1.81) <.001 1.29 (1.07,1.56) .008 HDP/GDM 2.44 (1.19,5.01) .015 1.63 (0.78,3.41) .187 Macrosomia Unaffected Reference Reference HDP alone 1.15 (0.76,1.72) .497 0.88 (0.58,1.34) .566 GDM alone 1.44 (1.12,1.85) .004 1.27 (0.98,1.64) .066 HDP/GDM 2.42 (0.99,5.90) .052 1.73 (0.69,4.29) .235 Low birthweight Unaffected Reference Reference HDP alone 6.53 (4.67,9.14) <.001 7.65 (5.35,10.93) <.001 GDM alone 1.14 (0.74,1.75) .537 1.17 (0.75,1.81) .471 HDP/GDM 9.96 (4.42,22.41) <.001 11.46 (4.91,26.71) <.001 Preterm delivery Unaffected Reference Reference HDP alone 5.28 (3.90,7.15) <.001 4.76 (3.47,6.53) <.001 GDM alone 1.76 (1.31,2.37) <.001 1.67 (1.23,2.25) <.001 HDP/GDM 5.26 (2.26,12.25) <.001 4.51 (1.91,10.63) <.001 Post-term delivery Unaffected Reference Reference HDP alone 0.00 (0.00,0.00) .995 0.00 (0.00,0.00) .995 GDM alone 1.23 (0.15,9.74) .843 1.36 (0.16,11.23) .773 HDP/GDM 0.00 (0.00,0.00) .998 0.00 (0.00,0.00) .998 Cesarean section Unaffected Reference Reference HDP alone 5.07 (3.49,7.35) <.001 4.12 (2.82,6.02) <.001 GDM alone 1.42 (1.20,1.69) <.001 1.26 (1.05,1.50) .012 HDP/GDM 9.89 (2.36,41.42) .002 7.38 (1.74,31.23) .007 LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval. The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred,glucose level and year of treatment. Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth. Am J Obstet Gynecol 2025 Table 6 Neonatal and perinatal outcomes by different exposures for frozen embryo transfer Table 6 Outcome Exposure Frozen embryo Unadjusted Adjusted OR (95% CI) P- value aOR (95% CI) P value AGA Unaffected Reference Reference HDP alone 0.81 (0.67,0.97) .029 0.92 (0.76,1.11) .417 GDM alone 0.66 (0.58,0.76) <.001 0.74 (0.64,0.85) <.001 HDP/GDM 0.72 (0.44,1.17) .187 0.90 (0.55,1.47) .682 SGA Unaffected Reference Reference HDP alone 4.81 (3.68,6.28) <.001 5.60 (4.23,7.41) <.001 GDM alone 1.60 (1.17,2.18) .003 1.87 (1.37,2.57) <.001 HDP/GDM 5.00 (2.55,9.82) <.001 6.95 (3.49,13.83) <.001 LGA Unaffected Reference Reference HDP alone 0.68 (0.55,0.86) .001 0.57 (0.45,0.72) <.001 GDM alone 1.41 (1.23,1.63) <.001 1.22 (1.05,1.41) .007 HDP/GDM 0.79 (0.44,1.42) .450 0.58 (0.32,1.05) .073 Macrosomia Unaffected Reference Reference HDP alone 0.68 (0.49,0.95) .026 0.54 (0.39,0.77) <.001 GDM alone 1.50 (1.24,1.81) <.001 1.24 (1.02,1.51) .026 HDP/GDM 0.68 (0.27,1.69) .411 0.46 (0.18,1.15) .097 Low birthweight Unaffected Reference Reference HDP alone 8.14 (6.38,10.38) <.001 7.57 (5.86,9.78) <.001 GDM alone 1.98 (1.46,2.69) <.001 1.83 (1.34,2.50) <.001 HDP/GDM 7.22 (3.85,13.52) <.001 6.53 (3.44,12.39) <.001 Preterm delivery Unaffected Reference Reference HDP alone 5.58 (4.53,6.86) <.001 4.93 (3.97,6.12) <.001 GDM alone 2.04 (1.64,2.54) <.001 1.81 (1.45,2.27) <.001 HDP/GDM 5.67 (3.32,9.68) <.001 4.68 (2.71,8.09) <.001 Post-term delivery Unaffected Reference Reference HDP alone 0.67 (0.09,4.95) .697 0.60 (0.08,4.54) .627 GDM alone 0.00 (0.00,0.00) .990 0.00 (0.00,0.00) .990 HDP/GDM 0.00 (0.00,0.00) .997 0.00 (0.00,0.00) .997 Cesarean section Unaffected Reference Reference HDP alone 5.91 (4.38,7.99) <.001 5.22 (3.85,7.07) <.001 GDM alone 1.42 (1.23,1.64) <.001 1.20 (1.04,1.40) .011 HDP/GDM 3.78 (1.88,7.59) <.001 2.84 (1.40,5.77) .004 LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval. The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred, glucose level and year of treatment. Su. Hypertensive disorders of pregnancy and gestational diabetes mellitus affect fetal growth\. Am J Obstet Gynecol 2025
Neonatal and perinatal outcomes by different exposures for fresh embryo transfer
LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval.
The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred,glucose level and year of treatment.
Neonatal and perinatal outcomes by different exposures for frozen embryo transfer
LGA, large for gestational age and defined as the birthweight percentile over 90% for gestational age; SGA, small for gestational age and defined as the birthweight percentile under 10% for gestational age; AGA, appropriate for gestational age and defined as the birthweight percentile between 90% and 10% for gestational age (inclusive). aOR, adjusted odds ratio; CI, confidence interval.
The aOR and 95% CI were obtained via binary logistic regression analyses. Analyses were adjusted for age, BMI, systolic pressure, diastolic pressure, infertility cause, number of oocytes retrieved, endometrial thickness before embryo transfer, stage of embryo transferred, number of embryos transferred, glucose level and year of treatment.
Compared to unaffected pregnancies, those with GDM who underwent fresh embryo transfer (aOR: 1.29; 95% CI: [1.07–1.56]; P=. 008) or frozen embryo transfer (aOR: 1.22; 95% CI: [1.05–1.41]; P=. 007) had a greater risk of LGA. Women with GDM who underwent frozen embryo transfer had increased risks of macrosomia (aOR: 1.24; 95% CI: [1.02–1.51]; P=. 026), low birth weight (aOR: 1.83; 95% CI: [1.34–2.50]; P<. 001), and SGA (aOR: 1.87; 95% CI: [1.37–2.57]; P<. 001) compared to unaffected pregnancies. In contrast, women with GDM who underwent fresh embryo transfer did not have an increased risk of macrosomia (aOR: 1.27; 95% CI: [0.98–1.64]; P=. 066), low birth weight (aOR: 1.17; 95% CI: [0.75–1.81]; P=. 471), or SGA (aOR: 0.83; 95% CI: [0.53–1.29]; P=. 419).
We also found that women who underwent either fresh or frozen embryo transfers and had pregnancies affected by HDP/GDM had greater risks of SGA, low birthweight, preterm delivery, and cesarean section compared to unaffected pregnancies. Additionally, pregnancies affected by either HDP alone or GDM alone had greater risks of preterm delivery and cesarean section compared to unaffected pregnancies.
Discussion
In this study we found several key associations between HDP, GDM, and risk of adverse pregnancy outcomes among women who successfully underwent conventional IVF. Pregnancies affected by HDP alone have greater risks of SGA, low birthweight, preterm delivery, and cesarean section than unaffected pregnancies. Pregnant women affected by GDM alone have greater risk of SGA, low birthweight, LGA, macrosomia, preterm delivery, and cesarean section compared to unaffected pregnant women. The comorbidity of HDP and GDM causes greater risk of SGA, low birthweight, preterm delivery, and cesarean section compared to unaffected pregnancies. A sub-analysis of fresh embryo and frozen embryo transfer among the four exposure groups found that, regardless of whether women underwent frozen or fresh embryo transfer, compared with the unaffected pregnancies, the risks associated with HDP and HDP/GDM co-morbidity remained similar.
Several studies have shown that GDM is associated with a greater risk of preeclampsia, cesarean delivery, preterm birth, macrosomia, LGA, shoulder dystocia, hypoglycemia, and jaundice in newborns. 23 , 24 , 25 , 26 Our results align with these studies, supporting the relationship between GDM and LGA, macrosomia, cesarean delivery, and preterm delivery. Interestingly, we found that GDM was also a risk factor for SGA and low birthweight infants, which has not been reported previously and may be a risk specific to IVF pregnancies.
Some studies have reported that HDP increases the risk of low birthweight, SGA, preterm birth, cesarean section and NICU admission. 10 , 27 , 28 Our results align with these studies, supporting an association between HDP alone and SGA, low birthweight, cesarean delivery, and preterm delivery in IVF pregnancies.
Previous data on the impact of HDP/GDM comorbidity on birthweight outcomes of pregnancies is limited and inconsistent. A study conducted in 2017 that compared birthweight outcomes between pregnancies affected by GDM and those with both HDP and GDM in China indicated that pregnancies complicated by HDP/GDM were associated with a higher risk of LGA infants compared to those solely affected by GDM. 29 Onuoha et al. reported that pregnancies concurrently affected by HDP/GDM have a greater risk of neonatal morbidity, 30 whereas the relative risks of LGA and SGA were not significantly different between HDP/GDM pregnancies and unaffected pregnancies. In contrast, our findings highlight that the rates of SGA, low birthweight, cesarean delivery, and preterm delivery are greater in HDP/GDM pregnancies than in unaffected pregnancies. Our findings imply that, in HDP/GDM comorbidity, the LGA risk usually associated with GDM is not present due to HDP’s SGA influence taking precedence. The specific underlying mechanisms driving this relationship warrant further exploration. Most existing studies of the effects of GDM or HDP on fetal growth have focused on the general pregnant population, confirming associations between GDM and LGA, HDP and SGA, and the co-occurrence of HDP and GDM affecting fetal growth and neonatal outcomes. 10 , 11 , 30 While our study largely supports previous findings, contradictions between our results and others may be due to differences between IVF and normal pregnancy cohorts. Notably, although HDP, GDM, and HDP/GDM have similar effects on perinatal and neonatal outcomes in naturally conceived and IVF women, previous studies have shown that IVF itself can impact perinatal and neonatal outcomes. 31 While this study focused specifically on the effects of HDP, GDM, and HDP/GDM on perinatal and neonatal outcomes within the IVF population, it cannot be concluded that IVF alone 32 does not independently affect perinatal outcomes due to our limited sample size. Further large-scale cohort studies and mechanistic investigations are needed to clarify the specific contributions of HDP, GDM, and IVF to fetal growth and perinatal outcomes in both IVF and naturally conceived populations.
Currently, it remains unclear whether the differences in pregnancy outcomes among women undergoing IVF, including those associated with HDP and GDM, are due to infertility-related maternal factors, ART practices, or both. Many studies have investigated the effects of ART on neonatal and perinatal outcomes. A meta-analysis by Rogue et al. revealed that, compared with fresh embryo transfer, frozen embryo transfer is associated with a greater rate of low birth weight and preeclampsia. 31 However, some studies have reported no differences in birth weight between fresh and cryopreserved embryo transfers, 33 making the effects of fresh embryo transfer versus frozen embryo transfer on birth weight controversial. We found that regardless of whether women underwent frozen or fresh embryo transfers, pregnancies affected by HDP/GDM had greater risks of SGA, low birthweight, preterm delivery, and cesarean section, suggesting slowed or delayed growth when compared to unaffected pregnancies. HDP pregnancies that involved either fresh or frozen embryo transfer had a greater risk of SGA and low birthweight compared to unaffected pregnancies. GDM pregnancies with either fresh or frozen embryo transfer occurred had a greater risk of LGA, and GDM pregnancies with frozen embryo transfer had increased risk of macrosomia, low birthweight, and SGA compared to unaffected pregnancies. The exact contribution of HDP and GDM, as well as the type of embryo transfer (frozen or fresh), to the observed effects on neonatal weight and perinatal outcomes need to be further investigated.
A strength of our study is its large sample size and data integrity, which enabled us to thoroughly investigate the risks of neonatal weight and perinatal outcomes. Additionally, we excluded patients with pregestational diabetes, chronic hypertension, and maternal age>40 years, which are potential confounders for fetal growth and perinatal outcomes, 34 , 35 thus minimizing their impact of these confounders on our results. Furthermore, this is the first study to examine the effects of HDP/GDM on neonatal weight and perinatal outcomes in the IVF population. However, this study also has several limitations. First, it was conducted at a single academic medical center and affiliated community sites, potentially limiting its generalizability. Second, the dataset used for analyses was derived from clinical rather than research data; which may have introduced unmeasured confounding. For instance, information on several factors known to influence fetal growth—such as fetal anomalies, smoking status 36 and glucose control status 37 —was unavailable, partly due to the reliance on telephone follow-up. Moreover, given the limitations of retrospective clinical data and the need to enhance the robustness of the findings, further prospective studies are warranted. Further investigations should be performed to identify the mechanisms and pathways contributing to birth weight and perinatal outcomes in IVF pregnancies affected by HDP and GDM.