Maternal T1D a risk factor for congenital heart defects in offspring

Babies born to mothers with type 1 diabetes (T1D) are at increased risk of congenital heart defects (CHDs), as shown in a study.

For the study, researchers used data from a birth cohort from Finland consisting of all children born between 2006 and 2016 (n=620,751, 51.0 percent boys) and their mothers. Maternal prepregnancy body mass index (BMI) was categorized as underweight (<18.5 kg/m²), normal (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obese (≥30 kg/m²). Maternal diabetes status was classified as no diabetes, T1D, type 2 or other diabetes, and gestational diabetes.

Isolated CHD was identified in 10,254 children (1.7 percent). Multivariable logistic regression analysis showed that compared with no maternal diabetes, maternal T1D was associated with greater odds of having a child with any CHD (odds ratio [OR], 3.77, 95 percent confidence interval [CI], 3.26–4.36).

The association was observed for six out of nine CHD subgroups, including other septal defects (OR, 3.28, 95 percent CI, 1.55–6.95) and transposition of great arteries (OR, 7.39, 95 percent CI, 3.00–18.21), among others.

Additional data showed that maternal overweight was associated with left ventricular outflow tract obstruction (OR, 1.28, 95 percent CI, 1.10–1.49) and ventricular septal defects (OR, 0.92, 95 percent CI, 0.86–0.98) compared with normal maternal BMI. Maternal obesity also contributed to increased risks of complex defects (OR, 2.70, 95 percent CI, 1.14–6.43) and right outflow tract obstruction (OR, 1.31, 95 percent CI, 1.09–1.58).