Association of interpregnancy interval and gestational diabetes mellitus

To evaluate the association between interpregnancy interval (IPI) and risk for gestational diabetes mellitus (GDM).

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.

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).

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.