A new study has found that women who take oral contraceptives just before or during pregnancy do not have an increased risk of birth defects. Findings from the study are published in BMJ.

Oral contraceptives are >99% effective with perfect use but almost 10% of women who take oral contraceptives become pregnant within their first year. Many women will discontinue oral contraceptive use when planning a pregnancy and become pregnant within a few months. Not much is known, however, about the potential health risks to children from in utero exposure to the hormones in oral contraceptives. 

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Researchers from Harvard T.H. Chan School of Public Health and the Statens Serum Institut in Denmark obtained data collected from multiple Danish health registries between 1997–2011. They evaluated 880,694 live-born infants and the health of these children after a one-year follow-up. Oral contraceptive use was estimated based on the mother’s most recent prescription fill date. 

Of the total women in the study, one-fifth had never used oral contraceptives prior to becoming pregnant and over two-thirds discontinued oral contraceptives at least 3 months prior to becoming pregnant. Study authors reported that 8% had discontinued use within 3 months of becoming pregnant and 1% had used oral contraceptives after becoming pregnant. 

The study found that the prevalence of birth defects was steady across each category of oral contraceptive use even after adjusting for pregnancies that ended as stillbirths or induced abortions. Exposure to oral contraceptives just before or during pregnancy did not appear to be associated with an increased risk of major birth defects, study authors concluded. 

For more information visit bmj.com.