Maternal obesity and infant heart defects

Obes Res. 2003 Sep;11(9):1065-71. doi: 10.1038/oby.2003.146.


Objective: This study determined whether obese women have an increased risk of cardiovascular defects in their offspring compared with average weight women.

Research methods and procedures: In a case-control study, prospectively collected information was obtained from Swedish medical health registers. The study included 6,801 women who had infants with a cardiovascular defect and, as controls, all delivered women (N = 812,457) during the study period (1992 to 2001). Infants with chromosomal anomalies or whose mothers had pre-existing diabetes were excluded. Obesity was defined as BMI >29 kg/m(2), and morbid obesity was defined as BMI >35 kg/m(2). Comparisons were made with average weight women (BMI = 19.8 to 26 kg/m(2)).

Results: In the group of obese mothers, there was an increased risk for cardiovascular defects compared with the average weight mothers [adjusted odds ratio (OR) = 1.18; 95% CI, 1.09 to 1.27], which was slightly more pronounced for the severe types of cardiovascular defects (adjusted OR = 1.23; 95% CI, 1.05 to 1.44). With morbid obesity, the OR for cardiovascular defects was 1.40 (95% CI, 1.22 to 1.64), and for severe cardiovascular defects, the OR was 1.69 (95% CI, 1.27 to 2.26). There was an increased risk for all specific defects studied among the obese women, but only ventricular septal defects and atrial septal defects reached statistical significance.

Discussion: In this sample, a positive association was found between maternal obesity in early pregnancy and congenital heart defects in the offspring. A suggested explanation is undetected type 2 diabetes in early pregnancy, but other explanations may exist.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Case-Control Studies
  • Confidence Intervals
  • Female
  • Heart Defects, Congenital / epidemiology
  • Heart Defects, Congenital / etiology*
  • Humans
  • Infant, Newborn
  • Middle Aged
  • Obesity / complications*
  • Obesity / epidemiology
  • Obesity, Morbid / complications
  • Odds Ratio
  • Parity
  • Pregnancy
  • Pregnancy Complications* / epidemiology
  • Pregnancy Outcome
  • Prevalence
  • Prospective Studies
  • Risk Factors
  • Sweden / epidemiology