Diabetes in pregnancy (DIP) is associated with adverse outcomes. We aim to determine gaps in antenatal care and outcomes among women with diabetes or prediabetes to improve care delivery in our cohort.

We performed a retrospective review of women with type 1 diabetes (T1D), type 2 diabetes (T2D), or prediabetes who attended endocrine pregnancy clinic from 1 January 2022 to 31 December 2024. Clinical variables and pregnancy outcomes were collected and compared across diabetes subtypes using Kruskal–Wallis test.

Among 288 pregnancies, median age at ~12 weeks’ gestation was 33 (IQR 30, 36) years and median pre-pregnancy BMI 29.3 (26.0, 34.0) kg/m². Ethnic distribution was Chinese 16.8%, Malay 33.5%, Indian 14.4%, and others 9.5%. Prior smoking was reported in 5.6%; chronic hypertension and prior gestational hypertension/preeclampsia affected 9.1% and 4.2%, respectively. Diabetes subtypes were T1D 5.2% (n=15), T2D 71.5% (n=206), and prediabetes 23.3% (n=67). First-trimester HbA1c was higher in T1D (8.5%) versus T2D (7.1%) and prediabetes (5.7%) (overall p<0.001), with progressive improvement across gestation (second trimester 6.2%, third trimester 6.1% overall; both p<0.001 between groups). Process-of-care indicators showed high folic acid (95.1%) and aspirin (70.1%) use, yet screening gaps persisted: only 68.7% had documented retinopathy assessment. Significant proteinuria occurred in 9.8%. Treatment patterns were diet/lifestyle 19.1%, metformin alone 5.6%, insulin alone 58.7%, and insulin-metformin 16.7%. For insulin users, median pre-pregnancy weight-adjusted dose was 0.6 (0.28–1.02) units/kg, higher in T1D (1.0) than T2D (0.6) or prediabetes (0.4) (p<0.001). Basal regimens were predominantly detemir, with smaller use of glargine or human NPH. Modes of delivery were vaginal delivery 38.3%, elective caesarean section 26.8%, emergency caesarean section 33.6%, and assisted vaginal delivery 1.3%. Median birthweight was 3025 g (IQR 2683, 3375). Adverse outcomes included miscarriage 6.0%, preterm birth 14.1%, pre-labour rupture of membranes 7.4%, neonatal ICU admission 5.2%, neonatal respiratory distress 2.6%, and one stillbirth.

Glycaemic control improved through pregnancy, yet care gaps remain. Optimisation of preconception BMI, early intensification of glycaemic management—especially in T1DM, and close screening gaps (e.g., retinal assessment) are needed to further reduce risk and improve outcomes.