Does spacing pregnancies help women with gestational diabetes?

Women with a history of gestational diabetes were 50 percent more likely to have a short interval between pregnancies compared to women without the condition, suggests a new study.

“The proportion of short interpregnancy intervals – 18 months or shorter spacing between a live birth and the beginning of the next pregnancy – was higher in women with a history of gestational diabetes vs those without gestational diabetes, and this reached statistical significance [56.4 percent vs 43.6 percent; p<0.001],” reported lead researcher Dr Ronald Anguzu from the Medical College of Wisconsin, Milwaukee, Wisconsin, US at ADA Virtual 2020. [ADA 2020, abstract 192-OR]

Anguzu said intervals of 18 months or less between pregnancies are linked to adverse outcomes which included spontaneous abortion, preterm birth, and low birth weight.

Intervening to prolong these intervals might provide an opportunity for pre-conception counselling, in addition to screening and management of type 2 diabetes (T2D), he proposed.

Problem with undiagnosed diabetes

Anguzu said promoting education and strategies for birth spacing in this high-risk group is crucial given that conception in the setting of undiagnosed and uncontrolled diabetes carries significant health risks to both the mother and her baby.

Although gestational diabetes is usually temporary and goes away after the baby is born, Dr Mary Loeken, chair of the ADA Scientific Sessions Planning Subcommittee on Pregnancy and Reproductive Health, and associate professor at Harvard Medical School, Boston, Massachusetts, US, said most women who had gestational diabetes are at high risk of progressing to T2D.

“Entering pregnancy with T2D poses increased risks for the mother and foetus, including the possibility of congenital malformations,” she warned. “Hence, counselling these women to space their pregnancies may improve their health and that of their foetus in subsequent pregnancies.”

Maternal age, BMI: Is there a link?

Anguzu looked at data from 28,000 women aged 18–44 years from the US National Survey on Family Growth Data Sets from 2011–2017 and found a history of gestational diabetes in 9.9 percent of the participants.

These women had a higher mean maternal age vs those without a history of gestational diabetes (36.3 vs 34.3 years; p<0.001). Mean BMI in those with gestational diabetes was also greater vs those without a history ((31.3 kg/m² vs 27.9 kg/m²).

The odds ratio of having short interpregnancy intervals if the women had a history of gestational diabetes was 1.43 (95 percent confidence interval [CI], 1.22–1.66) vs those without gestational diabetes.

The association remained strong despite adjusting for confounding factors such as maternal age, BMI, race/ethnicity, marital status, education, family income, contraception use, and history of sexually transmitted infections (adjusted odds ratio, 1.49,  95 percent CI, 1.26–1.76).

“The implication is that perinatal complications may be reduced by lowering the number of short interpregnancy intervals in this population through effective contraception,” concluded Anguzu.