Background & Aim
Type 2 diabetes mellitus (T2DM) pregnancies carry increased risks of maternal and neonatal adverse outcomes, particularly higher rates of perinatal mortality, stillbirth, congenital anomalies, and hypertensive complications, as well as increased likelihood of caesarean delivery and preterm birth (1). This study aimed to evaluate obstetric and neonatal outcomes and identify predictors of complications in women with T2DM.
Method
A retrospective observational study was conducted at a tertiary obstetric hospital in Brisbane, Australia between January 2021 and December 2024.
Results
193 pregnancies in 169 women were analysed (0.83% of all pregnancies). Mean maternal age was 33.6±5.1 years, pre-pregnancy BMI 33.3±7.2kg/m², and gestational weight gain 13.7±10.4kg. Mean HbA1c was 7.49±2.09%, with most women managed with diet alone (31%) or a single oral hypoglycaemic agent (44%) preconception. BMI was not associated with HbA1c >6.5% (p=0.183), though a significant linear trend was observed (p=0.038). Caesarean delivery occurred in 60% (33% elective, 27% emergency). Maternal complications included preeclampsia (10.4%) and preterm prelabour rupture of membranes (5.2%). Major congenital malformations occurred in 11.4% and fetal/neonatal demise in 6.7%. Mean birthweight was 3179±925g, with 31% large and 12% small for gestational age.
Preconception HbA1c >6.5% was independently associated with congenital anomalies (adjusted OR 5.84, 95% CI 1.62–21.09, p=0.007), but not with birthweight, fetal growth category, preterm birth, or mode of delivery.
Conclusion
Preconception hyperglycaemia was an independent predictor of congenital anomalies, underscoring the importance of optimising glycaemic control prior to pregnancy.