First-Trimester Fasting Hyperglycemia and Adverse Pregnancy Outcomes

OBJECTIVE: The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study found strong associations between higher levels of maternal glucose at 24–32 weeks, within what is currently considered normoglycemia and adverse pregnancy outcomes. Our aim was to evaluate the associations between first-trimester fasting plasma glucose level and adverse pregnancy outcomes. RESEARCH DESIGN AND METHODS: Charts of all patients who delivered at our hospital between June 2001 and June 2006 were reviewed. Only subjects with singleton pregnancy and a recorded first-trimester fasting glucose level were included. Women with pregestational diabetes, fasting glucose level >105 mg/dl, or delivery <24 weeks were excluded. Fasting glucose levels were analyzed in seven categories, similar to the HAPO study. The main outcomes were development of gestational diabetes mellitus (GDM), large-for-gestational-age (LGA) neonates and/or macrosomia, and primary cesarean section. Multivariate logistic regression analysis was used; significance was <0.05. RESULTS: A total of 6,129 women had a fasting glucose test at median of 9.5 weeks. There were strong, graded associations between fasting glucose level and primary outcomes. The frequency of GDM development increased from 1.0% in the lowest glucose category to 11.7% in the highest (adjusted odds ratio 11.92 [95% CI 5.39–26.37]). The frequency of LGA neonates and/or macrosomia increased from 7.9 to 19.4% (2.82 [1.67–4.76]). Primary cesarean section rate increased from 12.7 to 20.0% (1.94 [1.11–3.41]). CONCLUSIONS: Higher first-trimester fasting glucose levels, within what is currently considered a nondiabetic range, increase the risk of adverse pregnancy outcomes. Early detection and treatment of women at high risk for these complications might improve pregnancy outcome.