Maternal outcomes among women with type 1 diabetes in Sweden. A population-based cohort study

• Women with type 1 diabetes face significantly higher risks of pregnancy and birth complications compared to women without type 1 diabetes. • There is a need for targeted research to optimize perinatal care and support for pregnant women with type 1 diabetes. • Additional studies are required to clarify the underlying causes of increased maternal complications among women with type 1 diabetes. Type 1 diabetes (T1D) increases the risk of pregnancy complications due to hyperglycemia and vasculopathy, leading to higher rates of preeclampsia and obstetric interventions. A contemporary reassessment of maternal and obstetric outcomes in women with T1D is needed, considering care for women with T1D in Sweden is inequitable. This study aimed to investigate maternal and obstetric outcomes among women with T1D in Sweden. In this population-based cohort study, data from the Swedish Medical Birth Register were used to compare maternal and obstetric outcomes among women with and without T1D. The study included all primiparous women with singleton births beyond 22 + 0 gestational weeks and a planned vaginal delivery between 2010 and 2022 (N = 558 546). Logistic regression analyses were performed, and results are presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Among the study population, 2749 women had T1D and 555 797 did not. After adjustment, women with T1D had increased odds of preeclampsia (aOR 5.57; 95% CI 5.07–6.16), induction of labor (aOR 6.62; 95% CI 6.11–7.18), cesarean section (aOR 4.71; 95% CI 4.35–5.11), and shoulder dystocia (aOR 11.81; 95% CI 9.20–15.17). Elevated risks were also observed for vacuum extraction, prolonged labor, fetal distress, and postpartum endometritis. Women with T1D face substantially higher risks of pregnancy complications and birth interventions compared with women without T1D. These findings underscore the importance of tailored preconception and perinatal care, as well as targeted interventions to improve maternal and obstetric outcomes in T1D.