Poor pregnancy outcome in women with type 1 diabetes is predicted by elevated HbA1c and spikes of high glucose values in the third trimester

Objective: To analyse data from a randomised, controlled study of prandial insulin aspart versus human insulin, both with NPH insulin, in pregnant women with type 1 diabetes for potential factors predicting poor pregnancy outcomes. Research design/method: Post hoc analysis including 91 subjects randomised prior to pregnancy with known outcome in early pregnancy and 259 subjects randomised prior to pregnancy/during pregnancy of <10 weeks' gestation with known late-pregnancy outcomes. Poor early-pregnancy outcomes included fetal loss <22 gestational weeks and/or congenital malformation (n = 18). Poor late-pregnancy outcomes included: composite endpoint including pre-eclampsia, preterm delivery and perinatal death (n = 78); preterm delivery (n = 63); and excessive fetal growth (n = 88). Results: 18 patients experienced a malformed/lost fetus in early pregnancy-none preceded by severe hypoglycaemia. Albuminuria in early pregnancy was a significant predictor of poor late-pregnancy outcome (composite endpoint; p = 0.012). In the third trimester, elevated HbA1c, ≥ 1 plasma glucose (PG) measurement >11 mmol/L (198 mg/dL) and %PG values outside 3.9-7.0 mmol/L (70-126 mg/dL) were significant predictors of poor late-pregnancy outcomes (all p < 0.05). Conclusions: Elevated HbA1c, high glucose spikes and out-of-range %PG in the third trimester, and albuminuria in early pregnancy, are associated with poor late-pregnancy outcomes.