An elevated pre-pregnancy HbA1c — which measures average blood glucose concentration — is associated with a higher risk of adverse pregnancy outcomes even in women without known diabetes, according to a new study published recently in PLOS Medicine.
Diabetes mellitus and obesity are both associated with adverse pregnancy outcomes but the relationship between pre-pregnancy A1c and severe maternal morbidity or maternal mortality is unknown.
Overall, the risk of severe maternal morbidity (SMM) or death from 23 weeks gestation to 6 weeks postpartum was 2.2%. For each 0.5% absolute increase in A1c, the relative risk of SMM or death was 1.16 (95% CI 1.14-1.19, p(0.001) after adjusting for maternal age, multifoetal pregnancy, world region of origin, and tobacco/drug dependence.
The authors note that most women do not undergo A1c testing, which may have led to selection bias among the cohort. Additionally, pre-pregnancy body mass index was unknown for 77% of the participants. Therefore, the potential interaction between BMI, A1c and risk of SMM should be investigated further. Still, these findings have implications for pre-pregnancy health screening.