Abstract
Objective
The Society for Maternal–Fetal Medicine and American College of Obstetricians and
Gynecologists recommend delivery of gravidae with pregestational diabetes at 36 to
396/7 weeks based on glycemic control and vascular complications. The optimal gestational
age within this wide range is unknown. Our objective was to evaluate the risk of adverse
outcomes with delivery versus expectant management at increasing gestational ages.
Study Design
Retrospective cohort study of gravidae with pregestational diabetes who delivered
a nonanomalous singleton at ≥36 weeks (2012–2022). The primary outcome was composite
neonatal morbidity: hypoglycemia, hyperbilirubinemia, shoulder dystocia, and perinatal
death. Secondary outcomes included composite components, composite severe neonatal
morbidity, large-for-gestational-age, small-for-gestational-age (SGA), NICU admission,
and cesarean. Poisson regression with robust error variance estimated the association
between delivery at 36, 37, and 38 weeks and outcomes, compared with expectant management.
Results
Eight hundred forty-three gravidae met inclusion criteria: 235 (28%) type 1 diabetes
and 602 (71%) type 2 diabetes. Overall, 146 (17%) delivered at 36 weeks, 283 (34%)
at 37 weeks, 217 (26%) at 38 weeks, and 197 (23%) at ≥39 weeks. Compared with expectant
management, delivery at 36 weeks was associated with higher odds of composite morbidity
(adjusted risk ratio: 1.31; 95% confidence interval: 1.11–1.55) as well as hypoglycemia,
hyperbilirubinemia, SGA, and NICU admission. At 37 and 38 weeks, there was no significant
difference in composite morbidity among those delivered versus expectantly managed.
However, delivery at 37 weeks was associated with higher odds of hyperbilirubinemia,
compared with expectant management. No other outcomes differed between delivery versus
expectant management at 37 or 38 weeks. Few associations differed by diabetes type.
Conclusion
Based on these results and supporting literature, elective delivery at 36 weeks should
be avoided unless necessary. Although the data are inconclusive regarding delivery
at 37 weeks, delivery at 38 weeks should be evaluated further for gravidae with pregestational
diabetes. Confirmation in a large, contemporary cohort or a randomized trial is needed.
Key Points
-
Elective delivery of gravidae with diabetes at 36 weeks should be avoided given neonatal
morbidity.
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Delivery of gravidae with diabetes at 37 weeks versus expectant management may increase
morbidity.
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Delivery of gravidae with diabetes at 38 weeks didn't increase morbidity but needs
further study.
Keywords
delivery - diabetes - morbidity - neonatal - pregestational - pregnancy - timing
