“Given that progesterone is a key hormone in pregnancy, the use of progestin-containing OCPs before pregnancy could influence fetal respiratory and immune development,” explained study first author Dana B. Hancock, PhD. “In 1997, researchers postulated that a mother’s OCP use may increase the risk of asthma in the child. Since then, a few studies have supported evidence for this hypothesis but data are limited and inconclusive.”
In the Norwegian Mother and Child Cohort Study, Hancock and colleagues looked at associations between the type of OCP used by the mother before pregnancy and lower respiratory tract infections in 60,225 children followed to 6 months old, lower respiratory tract infections and wheezing in 42,520 children followed to 18 months old and asthma in 24,472 children followed to 36 months old.
The use of estrogen-progestin combined pills before pregnancy was not associated with lower respiratory tract infections, wheezing or asthma in the children followed in the study. Progestin-only pill use in the year before pregnancy had a small positive association with wheezing in children at 6 to 8 months but the researchers noted that very few women used this type of pill.
“We found that use of the combined pill, taken by most women who use OCPs, was not associated with adverse respiratory outcomes in the offspring. This should provide reassurance to the vast majority of women using OCPs during their childbearing years. The small association with the much less commonly used progestin-only pill may not reflect cause and effect but does suggest that researchers look at these two types of pills separately in the future,” said Stephanie J. London, MD, DrPH, principal investigator at the National Institute of Environmental Health Sciences and senior author of the study.
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- This study was presented during the 2011 Annual Meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI) on March 18-22 in San Francisco. However, it does not necessarily reflect the policies or the opinions of the AAAAI.
- A link to all abstracts presented at the Annual Meeting is available at www.annualmeeting.aaaai.org
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Note to media: See abstract 662