Perinatal Outcomes of Type 1 and Type 2 Diabetes in Pregnancy: A 10-Year Single-Centre Cohort Study

Background/Objectives: Previous studies have examined perinatal outcomes in women with type 1 (T1DM) or type 2 diabetes (T2DM) in pregnancy compared with the general population, but few have directly assessed the impact of T1DM and T2DM on pregnancy outcomes both against each other and the general population. The aim of this study is to compare the perinatal outcomes between women with pre-existing T1DM and T2DM in pregnancy and women without diabetes in pregnancy. Methods: This is a retrospective single-centre cohort study from January 2010 through December 2019, including 2050 singleton pregnancies with T2DM (n = 317), T1DM (n = 92) and controls (n = 1641). Results: Women with T2DM were older (T2DM vs. T1DM, 33.4 vs. 29.7 yrs, p < 0.001), had higher BMI (35.4 vs. 26.8 kg/m2, p < 0.001), and were more likely multiparous (75.4 vs. 55.4%, p < 0.001). T1DM was associated with poorer glycaemic control throughout pregnancy. Infants of mothers with T1DM had increased rates of large for gestational age (45.0 vs. 26.1%, p = 0.005) and neonatal hypoglycaemia (38.0 vs. 20.8%, p < 0.001). The risk of perinatal death was nine-fold higher for T1DM (OR 9.27, p = 0.01) and 13-fold for T2DM (OR 13.5, p < 0.001) compared to controls, with no significant difference between diabetes types. Conclusions: Women with pre-existing diabetes had poorer perinatal outcomes compared to women without diabetes. Women with T2DM compared to T1DM had a similar risk of perinatal death, despite better glycaemic control and shorter duration of diabetes.