Interpregnancy weight change and recurrence of gestational diabetes mellitus: a population-based cohort study

Abstract

Objective: To estimate recurrence risk of gestational diabetes mellitus (GDM) by interpregnancy weight change. Design: Population-based cohort study. Setting and population: Data from the Swedish (1992–2010) and the Norwegian (2006–2014) Medical Birth Registries on 2763 women with GDM in first pregnancy, registered with their first two singleton births and available information on height and weight. Methods: Interpregnancy weight change (BMI in second pregnancy minus BMI in first pregnancy) was categorised in six groups by BMI units. Relative risks (RRs) of GDM recurrence were obtained by general linear models for the binary family and adjusted for confounders. Analyses were stratified by BMI in first pregnancy (<25 and ≥25 kg/m2). Main outcome measure: GDM in second pregnancy. Results: Among overweight/obese women (BMI ≥25), recurrence risk of GDM decreased in women who reduced their BMI by 1–2 units (relative risk [RR] 0.80, 95% CI 0.65–0.99) and >2 units (RR 0.72, 95% CI 0.59–0.89) and increased if BMI increased by ≥4 units (RR 1.26, 95% CI 1.05–1.51) compared wth women with stable BMI (−1 to 1 units). In normal weight women (BMI <25), risk of GDM recurrence increased if BMI increased by 2–4 units (RR 1.32, 95% CI 1.08–1.60) and ≥4 units (RR 1.61, 95% CI 1.28–2.02) compared with women with stable BMI. Conclusion: Interpregnancy weight loss reduced risk of GDM recurrence in overweight/obese women. Weight gain between pregnancies increased recurrence risk for GDM in both normal and overweight/obese women. Our findings highlight the importance of weight management in the interconception window in women with a history of GDM. Tweetable abstract: Interpregnancy weight loss reduces recurrence of gestational diabetes mellitus in overweight/obese women.