Preconception Prediabetes in Young Women and Adverse Birth Outcomes: Daily Dose

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On September 25, 2024, we reported on findings from a study published in JAMA Network Open that examined the association of preconception HbA1c levels among adolescents and young adults with risk of gestational diabetes at first live birth.

The study

Researchers conducted a retrospective cohort study using linked birth registry, hospital discharge and NYC Department of Health A1c Registry data from 2009 to 2017 for girls and young women aged 10 to 14 years.

Study inclusion required at least one HbA1c measurement prior to a first pregnancy and no prior record of diabetes or an HbA1c value equal to or greater than 6.5%. For the analysis, an HbA1c value before conception of 5.6% or less was defined as normoglycemia and an HbA1c of of 5.7% to less than 6.5% as prediabetes. The primary outcome was gestational diabetes at first birth.

The findings

The final cohort of 14 302 had a mean age of 22.1 years; 41% self-identified as Hispanic, 29% as Black, 18.1% as White, and 10.6% as Asian. Stratified by age, the majority (93.8%) were aged 20 to 24 years, and 6.2% were between age 10 and 19 years.

Before pregnancy, the researchers reported, more than three-quarters of the women (79.7%) were classified as having normoglycemia and 20.2% had HbA1c in the prediabetes range. After they had adjusted for prepregnancy characteristics, investigators found that the women with preconception prediabetes had an adjusted relative risk (aRR) of 2.21 (95% CI, 1.91 -2.56) for gestational diabetes compared with women who had normoglycemia before pregnancy.

Authors' comment

“Given alarming trends in adolescent obesity and diabetes risk and the high prevalence of unplanned pregnancies in adolescence and young adulthood, our results support expanded preconception screening as a mechanism to intervene on excess cardiometabolic risk earlier in the life course.”

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