Longer interpregnancy intervals tied to gestational diabetes risk in later pregnancy

Key takeaways:

• Interpregnancy intervals of 24 months or longer were associated with greater gestational diabetes risk in next pregnancy.
• Short or long intervals and gestational diabetes history were also tied to risk.

Interpregnancy intervals of 24 months or longer were associated with higher risk for gestational diabetes in later pregnancies, independent of maternal age, researchers reported in BMC Pregnancy and Childbirth.

“Studies from Canada and the United States have suggested that a short interpregnancy interval increases the risk of gestational diabetes in the second pregnancy, whereas research from Australia found that a shorter interpregnancy interval had a protective effect on the risk of gestational diabetes,” Yuqing Deng, MD, from the Center of Obstetrics and Gynecology at Peking University Shenzhen Hospital, the Institute of Obstetrics and Gynecology at Shenzhen PKU-HKUST Medical Center and the Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecologic Diseases, China, and colleagues wrote. “Results concerning the association between long interpregnancy interval and gestational diabetes also differ between studies.”

Deng and colleagues conducted a retrospective cohort study with data from 2,392 women with consecutive deliveries from 2013 to 2021 at Peking University Shenzhen Hospital. Researchers stratified the analysis based on age at first pregnancy, BMI and gestational diabetes history.

Researchers observed interpregnancy intervals of less than 12 months (n = 342), 12 to less than 18 months (n = 378), 18 to less than 24 months (n = 403), 24 to less than 36 months (n = 625), 36 to less than 48 months (n = 362), 48 to less than 60 months (n = 191) and 60 months or longer (n = 91). Overall median interpregnancy interval was 24.72 months.

Women with vs. without gestational diabetes in a subsequent pregnancy had longer median interpregnancy intervals (P < .05). Researchers observed a higher risk for gestational diabetes in a subsequent pregnancy for women with interpregnancy intervals of 24 to less than 36 months (adjusted OR = 1.585; 95% CI, 1.021-2.462), 36 to less than 48 months (aOR = 2.381; 95% CI, 1.489-3.809), 48 to less than 60 months (aOR = 2.488; 95% CI, 1.441-4.298) and 60 months or longer (aOR = 2.565; 95% CI, 1.294-5.087) compared with intervals of 18 to less than 24 months.

Mean BMI was not significantly different between women with interpregnancy intervals of less than 24 months and those with intervals of 24 months or longer.

Interpregnancy intervals of 36 months or longer were all associated with increased gestational diabetes risk in a subsequent pregnancy for women younger than 30 years and for those aged at least 30 years with or without gestational diabetes history (P < .05). In addition, interpregnancy intervals of less than 18 months were not significantly associated with gestational diabetes risk in a subsequent pregnancy.

Among women with vs. without a history of gestational diabetes, interpregnancy intervals of 12 to less than 18 months (aOR = 2.619; 95% CI, 1.074-6.386), 24 to less than 36 months (aOR = 3.747; 95% CI, 1.652-8.499), 36 to less than 48 months (aOR = 4.356; 95% CI, 1.724-11.005) and 60 months or longer (aOR = 5.373; 95% CI, 1.078-26.793) were significantly associated with risk for gestational diabetes in a subsequent pregnancy.

“These findings can be utilized by women to make informed decisions about the appropriate length of time between pregnancies in order to minimize the risk of gestational diabetes in subsequent pregnancies,” the researchers wrote.