1205-P: Abnormal Fetal Growth and Adverse Neonatal Outcomes in Pregnancies Affected by Both Gestational Diabetes and Hypertensive Disorders of Pregnancy

Objective: We evaluated how the co-occurrence of gestational diabetes (GDM) and hypertensive disorders of pregnancy (HDP) influence fetal growth and neonatal outcomes.

Methods: In a retrospective study of 47720 singleton deliveries from a US medical center, we compared the incidence of appropriate for gestational age birthweight (AGA) in pregnancies affected by GDM alone, HDP alone, or both GDM and HDP (GDM/HDP) to that in pregnancies affected by neither disorder (Control) using generalized estimating equations (covariates: maternal age, parity, BMI, insurance type, race, marital status, and prenatal care site). Secondary outcomes were small for gestational age birthweight (SGA), large for gestational age birthweight (LGA), and a neonatal composite outcome (stillbirth, hypoglycemia, hyperbilirubinemia, respiratory distress, encephalopathy, preterm delivery, neonatal death, NICU admission).

Results: Median [IQR] birthweight (BW) percentile in GDM/HDP (50 [24, 78], N=179) was similar to Control (50 [27, 73], N=35885), while GDM had increased (60 [35, 83], N=1322) and HDP had decreased (43 [18, 71], N=2749) BW percentiles. GDM (OR 0.8, P<0.001), HDP (OR 0.7, P<0.001), and GDM/HDP (OR 0.7, P=0.04) each had decreased odds of AGA. GDM had decreased SGA odds (OR 0.7, P=0.02) and increased LGA odds (OR 1.7, P<0.001). HDP had increased SGA odds (OR 2.0, P<0.001) and no difference in LGA odds (OR 0.99, P=0.914). While unadjusted rates of abnormal growth in GDM/HDP suggested that reduced AGA was due to excess LGA (14.5%) without excess SGA (7.3%), adjusted models suggested that both SGA (OR 1.3, P=0.33) and LGA (OR 1.4, P=0.12) contributed. GDM/HDP conferred the highest risk of neonatal morbidity (OR 3.4, P<0.001 compared to Control).

Conclusion: Although pregnancies with GDM/HDP co-occurrence have a similar median birth weight to unaffected pregnancies, they carry an increased risk of abnormal fetal growth and neonatal morbidity.