Objective: Type 1 diabetes mellitus (DM) is associated with a threefold to fivefold increased risk for stillbirth during pregnancy. The objective of the present study was to identify factors associated with prelabor urgent cesarean delivery for fetal compromise in women with type 1 DM.
Methods: We performed a nested case-control study within a prospective cohort of single pregnancies in women with type 1 DM managed with standardized protocols regarding treatment of diabetes and prenatal care. Twice-weekly home antenatal surveillance including nonstress test was initiated at 32 weeks of gestation and continued until planned delivery at 38-39 weeks of gestation. We identified factors associated with urgent cesarean delivery for an abnormal nonstress test. The calculated total sample size was 416 pregnancies. Independent factors and adjusted odds ratio (OR) were identified by logistic regression.
Results: Among 479 pregnancies, the rate of urgent cesarean delivery for an abnormal nonstress test was 4%. A hemoglobin A1C (Hb A1C) level at delivery of 6.4% or higher occurred in 34% of the pregnancies and was independently associated with urgent cesarean delivery (2% compared with 8%, P=.003, OR 4.16, 95% confidence interval 1.40-12.32). In the multivariable analysis, lack of preconception care and occurrence of gestational hypertension or preeclampsia were not associated with urgent cesarean delivery. The rate of stillbirth was 2 per 1,000.
Conclusion: In women with type 1 DM, an Hb A1C level at delivery of 6.4% or higher was associated with prelabor urgent cesarean delivery. This suggests that tight glycemic control throughout pregnancy might reduce the risk of late fetal compromise.
Level of evidence: III.