Abstract
OBJECTIVE: To evaluate the impact of pregestational diabetes on duration of active labour (DAL) in induced and spontaneous labour and to compare caesarean section (CS) rates and indications between women with and without diabetes. DESIGN: A population-based cohort study. SETTING: Sweden. POPULATION: 243 537 nulliparous women, registered in the Swedish Pregnancy Register, who delivered a singleton fetus at ≥ 34(+0) gestational weeks + days between 2014 and 2020. Women with gestational diabetes mellitus were excluded. METHODS: DAL was compared between women with pregestational diabetes and those without diabetes using Kaplan-Meier survival analysis and Cox regression analysis. MAIN OUTCOME MEASURES: DAL. Rates and indications for CS. RESULTS: Women with pregestational diabetes had longer active labour and a reduced chance of vaginal delivery at a given time-point compared to women without diabetes, adjusted hazard ratio 0.65 (95% CI: 0.60-0.70, p < 0.001). Among those with spontaneous labour, median DAL in diabetic vs. non-diabetic women was 9.60 h versus 8.75 h, difference 0.85 h (95% CI 0.20-1.50), p < 0.001. Corresponding numbers for induced labours were 8.92 h versus 7.20 h, difference 1.72 h (95% CI 0.94-2.49), p < 0.001. Elective and emergency CS rates were higher in women with pregestational diabetes than non-diabetic women (7.4% and 29.4% vs. 2.6% and 7.1% respectively), with suspected macrosomia (50.4%) and fetal distress (31.9%) being the most common indications for CS among women with pregestational diabetes. CONCLUSIONS: The prolonged labour duration in women with pregestational diabetes highlights the importance of the labour ward staff's support and patience in managing diabetic parturients, potentially allowing more time before diagnosing labour dystocia. Extended labour duration may also influence women's birth experience.