Evolution of maternal and neonatal outcomes before and after the adoption of the IADPSG/WHO guidelines in Belgium: A descriptive study of 444,228 pregnancies

To appraise adverse pregnancy outcomes after the adoption of IADPSG/WHO guidelines in Belgium. A retrospective study of the Center for Perinatal Epidemiology registry was conducted. Demographic changes and adverse pregnancy outcomes were compared between a pre- and post-guideline period in women with and without hyperglycemia in pregnancy (HIP). Adjusted odds ratios with a 95% confidence interval (CI) were used to compare maternal and neonatal outcomes controlling for potential confounders (maternal age, body mass index (BMI), hypertension, parity, and multiple births). The prevalence of HIP increased (6.0%–9.2%). In the overall population regardless of glycemic status, gestational weight gain (12.3 ± 5.7 vs 11.9 ± 5.8; p < 0.001), hypertension (0.92; 95% CI, 0.89–0.94; p < 0.001), and neonatal intensive care unit/special care nursery (0.89; 95% CI, 0.87–0.91; p < 0.001) decreased despite increasing maternal age and pre-pregnancy BMI. Emergency cesarean section rates (1.07; 95% CI, 1.05–1.09; p < 0.001) increased, but not in the HIP population (1.02; 95% CI, 0.95–1.10; ns). The overall incidence of preterm birth (1.09; 95% CI, 1.06–1.12; p < 0.001), stillbirth (1.10; 95% CI, 1.01–1.21; p < 0.05), and perinatal mortality (1.10; 95% CI, 1.01–1.19; p < 0.05) increased, except in the HIP population (1.03; 95% CI, 0.95–1.11; ns), (1.04; 95% CI, 0.74–1.47; ns) and (1.09; 95% CI, 0.80–1.49; ns), respectively. The overall incidence of small- for-gestational-age remained unchanged (0.99; 95%CI, 0.97–1.01; ns) regardless of glycemic status. In the HIP population, large-for-gestational age (0.90; 95% CI, 0.84–0.95; p < 0.001) and macrosomia (0.84; 95% CI, 0.78–0.92; p < 0.001) decreased. After the implementation of IADPSG/WHO guidelines, the prevalence of HIP increased by 53.7% and the incidence of major HIP-related pregnancy complications appears to be lower. However, we cannot conclude that the reduction of LGA-macrosomia is due to a better management of diabetes or due to greater recruitment of women with mild HIP associated with a lower risk of obstetrical complications. Pregnancy complications; IADPSG/WHO criteria; Diabetes; Gestational diabetes mellitus; Hyperglycemia in pregnancy; Epidemiology; Prevalence.