Higher maternal BMI tied to congenital heart defects risk in infants

Takeaway

• This meta-analysis suggests that increased maternal body mass index (BMI) is associated with an increased risk for congenital heart defects (CHDs) in infants.

Why this matters

• Maternal weight control before the plan to conceive is necessary to reduce the risk for CHDs in infants.

Study design

• 19 (6 cohort; 13 case-control) studies involving 2,416,546 participants met eligibility criteria after a search across PubMed, Embase, and Web of Science databases.
• Funding: The National Natural Science Foundation of China and others.

Key results

• Compared with the mothers with normal weight, the risk for CHDs in infants was higher for overweight (relative risk [RR], 1.08; 95% CI, 1.03-1.13; P=.003; I², 54.5%) and obese (RR, 1.23; 95% CI, 1.17-1.29; P=.005) mothers.
• The risk for CHDs in infants was increased with each 5 kg/m² increase in maternal BMI in the cohort (RR, 1.07; 95% CI, 1.06-1.08) and case-control (RR, 1.07; 95% CI, 1.05-1.09) studies.
• Compared with BMI of 22.05 kg/m², the risk for CHDs in infants was higher for BMI of:
  • 25 kg/m² (RR, 1.03; 95% CI, 1.02-1.04),
  • 30 kg/m² (RR, 1.08; 95% CI, 1.06-1.10),
  • 35 kg/m² (RR, 1.18; 95% CI, 1.16-1.21),
  • 40 kg/m² (RR, 1.36; 95% CI, 1.30-1.42) and
  • 45 kg/m² (RR, 1.42; 95% CI, 1.34-1.50).

Limitations

• Risk of bias.
• Overestimation of the true association between maternal obesity and risk for CHDs in infants.