Association of early pregnancy HbA1c levels with perinatal and postpartum outcomes in type 2 diabetes

Aims: Many pregnancies are unexpected. We therefore assessed the impact of an early pregnancy HbA1c above or below non-pregnant targets on perinatal outcomes and HbA1c trajectories throughout pregnancy and 12 months postpartum among individuals with type 2 diabetes. Methods: We conducted a retrospective cohort study of pregnant individuals with type 2 diabetes. Outcomes and HbA1c trajectories were compared among those who had an HbA1c <7% vs.  7% at <20 weeks’ gestation. Data were analyzed using logistic regression for perinatal outcomes and linear mixed models to assess trajectories of HbA1c during pregnancy and the postpartum period. Results: HbA1c was <7% in 128/281 (46%) and ≥7% in 153/281 (54%) individuals. HbA1c  7% was associated with risk for preterm birth (aOR 2.3, 95% CI 1.3-4.0), cesarean delivery (aOR 1.7, 95% CI 1.1-2.9), and neonatal intensive care admission (aOR 2.9, 95% CI 1.7-4.9). HbA1c values decreased during pregnancy in both groups but returned to early pregnancy values by the postpartum period. Conclusions: Adverse perinatal outcomes are high among individuals with type 2 diabetes mellitus regardless of early pregnancy glucose levels, and strategies are needed to improve maternal glucose levels in the postpartum period.

Publication History

Received: 10 June 2025

Accepted after revision: 13 August 2025

Accepted Manuscript online:
14 August 2025