Periconceptional use of weight loss products including ephedra and the association with birth defects

Background: : Weight loss products are frequently used by reproductive-aged women and these products may be taken (inadvertently or intentionally) during pregnancy. This study assessed the association between periconceptional use of weight loss products and major structural birth defects.

Methods: : Mothers of infants with birth defects (case infants) and a random sample of livebirths (control infants) born during the period 1998-2003 in 10 states participated in the National Birth Defects Prevention Study. Adjusted ORs (aORs) for the association between self-reported use of weight loss products and 23 categories of birth defects were calculated.

Results: : Mothers of control infants (2.4%) and 2.6% of mothers of case infants reported periconceptional use of weight loss products; 1.2% of mothers of control infants and 1.3% of mothers of case infants reported using an ephedra-containing product. Use of any weight loss product was associated with anencephaly (aOR 2.6; 95% CI: 1.3-5.3), dextro-transposition of the great arteries (aOR 2.1; 95% CI: 1.1-4.3), and aortic stenosis (aOR 3.4; 95% CI: 1.5-7.9). Use of products containing ephedra showed an increased aOR with anencephaly (aOR 2.8; 95% CI: 1.0-7.3), while other weight loss products were associated with dextro-transposition of the great arteries (aOR 1.8; 95% CI: 1.2-2.7), and aortic stenosis (aOR 2.1; 95% CI: 1.3-3.5).

Conclusions: : These results suggest an association between periconceptional use of weight loss products and certain birth defects but the possible mechanism is not clear. This is the first finding of such an association and, because we examined a large number of exposure-outcome associations in a hypothesis-generating analysis, these results might have been due to chance.