Effect of interpregnancy interval on the risk of gestational diabetes mellitus during a second pregnancy

Abstract

Purpose This study aimed to analyze the effect of interpregnancy interval (IPI) on the risk of gestational diabetes mellitus (GDM) in the Chinese population. Methods Female participants who had consecutive singleton deliveries in Peking University Shenzhen Hospital from 2013 to 2021 were selected for this retrospective cohort study. They were divided into GDM and non-GDM groups according to whether GDM was a complication in the second pregnancy. IPI and other possible GDM risk factors in the second pregnancy were assayed by univariate and multivariate logistic regression analysis. Results A total of 2,392 female participants were enrolled. The IPI of the GDM group was significantly greater than that of the non-GDM group (P < 0.05). Compared with the 18–23 months IPI category, participants with longer IPIs (24–35 months, 36–47 months, 48–59 months, and ≥60 months) had a higher risk of GDM (aOR:1.590, 2.390, 2.493, and 2.581; 95% CI: 1.026–2.464, 1.498–3.814, 1.447–4.297, and 1.303–5.109, respectively). The GDM risk was not significantly changed in participants with shorter IPIs (12–17 months, 18–23 months; P﹥0.05). A model consisting of IPI, maternal age, body mass index, and previous GDM manifested the best discrimination for GDM in the second pregnancy [AUC = 0.758 (95% CI: 0.728–0.788), P < 0.001]. For participants aged <35 years or without previous GDM, the risk of GDM significantly increased when the IPI was ≥36 months. The minimum IPI for a significant increase in GDM risk was 24–35 months in the participants with previous GDM. Conclusions An IPI longer than 24 months was associated with an increased GDM risk. The risk of GDM in a second pregnancy for women with previous GDM was more significantly affected by the IPI.