Maternal obesity and infant heart defects.
OBJECTIVE
This study determined whether obese women have an increased risk of cardiovascular defects in their offspring compared with average weight women.


METHODS
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.


CONCLUSIONS
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.
Cedergren
Marie I
MI
Division of Obstetrics and Gynaecology, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden. marie.cedergren@lio.se
Källén
Bengt A J
BA
D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D007231:Infant, Newborn; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D009767:Obesity, Morbid / Q000150:complications; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology