Association of interpregnancy interval and gestational diabetes mellitus

Objective: To evaluate the association between interpregnancy interval (IPI) and risk for gestational diabetes mellitus (GDM). Methods: We conducted a retrospective cohort study among singleton, non-anomalous, live birth pregnancies of 5,705,812 pregnant individuals in the United States from 2016 to 2018. We examined IPI of 4–<6 months, 6–11 months, 12–17 months, 24–35 months, 36–47 months, 48–59 months, 60–71 months, and ≥72 months in comparison to the reference interval of 18–23 months in relation to risk for GDM. We used logistic regression to evaluate the association between IPI and risk for GDM. Results: There is a significantly increased risk for GDM associated with IPIs of 6–11 months and 12–17 months compared to the reference of 18–23 months (adjusted Odds Ratio [aOR] 1.05, 95% CI: 1.03–1.07; aOR 1.02, 95% CI: 1.01–1.03). The risk for GDM is greater for longer IPIs (36–47 months aOR 1.10, 95% CI: 1.05–1.08; 48–59 months aOR 1.11, 95% CI: 1.09–1.13; 60–71 months aOR 1.14, 95% CI: 1.12–1.16; ≥72 months aOR 1.31, 95% CI: 1.30–1.33). Conclusion: Our findings support the growing evidence that shorter and longer IPI increase the risk of GDM in pregnant individuals. Screening guidelines for detection of GDM may need to be re-evaluated and updated to include longer IPIs (≥36 months) as a risk factor for earlier screening prior to current recommendation of 24 weeks gestational age.