Background: Pre-existing diabetes confers a risk of adverse outcomes in pregnancy[1]. The prevalence of type 1 (T1DM) and type 2 diabetes (T2DM) continues to increase in women of childbearing age[2]. The St. Vincent Declaration (1989) committed to improving outcomes for pregnant women with diabetes. The potential to deliver this aim may be possible as technology evolves, with recent research demonstrating the benefits of hybrid closed-loop systems using continuous subcutaneous insulin infusion (CSII) to improve maternal glycaemic control[3,4].
Objective: To evaluate recent perinatal outcomes of consecutive women with T1DM or T2DM presenting to an endocrine antenatal clinic in a single tertiary centre.
Methods: Retrospective cohort study utilising a standard template for data collection of women who delivered at John Hunter Hospital between January 1st and December 31st 2023.
Results: The cohort consisted of 48 pregnancies, including 22 in women with T2DM [age at conception 31.5(±5.6 SD); duration of diabetes 3.8(±3.8) years; 22.7% Aboriginal or Torres Strait Islander] and 26 in women with T1DM [age at conception 27.6(±4.8); duration of diabetes 13.5(±8.4) years; 19.2% Aboriginal or Torres Strait Islander]. Congenital malformation rates were similar for T2DM (22.7%) and T1DM (23.1%), and these pregnancies had higher preconception HbA1c (9.2% vs. 7.5%, p 0.037). One stillbirth occurred in a mother with T2DM and two mothers with T1DM experienced plurality loss. CGM was utilised frequently in T1DM (88.5%) and commonly in T2DM (45.5%). Ten women with T1DM used CSII. Preterm delivery (<37 weeks gestation) occurred in 18.2% of pregnancies complicated by T2DM and 37.0% for T1DM. Delivery occurred via Caesarean section in 66.7% of T2DM and 77.8% of T1DM including those with history of previous Caesarean section. Neonatal hypoglycaemia (<2.6mmol/L) occurred more commonly in neonates with mothers with T1DM than T2DM (48.1% vs. 14.3%, p 0.015). Babies born to mothers with T1DM were more likely to be large-for-gestational age than those with T2DM (64.0% vs 33.3%, p 0.038).
Conclusion: Adverse perinatal outcomes occurred at similar rates to those reported elsewhere[3], affirming pre-existing diabetes in pregnancy remains high risk. Further progress is required to meet the St. Vincent Declaration. CGM uptake was excellent, which improves safety and perinatal outcomes[5]. Areas highlighted for improvement as outcomes from this audit include: