Exposure to Oral Contraceptives Not Tied to Birth Defects
Findings should reassure women and their doctors, researchers say
THURSDAY, Jan. 7, 2016 (HealthDay News) -- Exposure to oral contraception in early pregnancy does not appear to increase the risk of birth defects, according to a study published online Jan. 6 in The BMJ.
Brittany Charlton, Sc.D., an instructor in the department of epidemiology at Harvard's T.H. Chan School of Public Health in Boston, and colleagues used national medical registries to collect data from Denmark from 1997 to 2011 on all live births, birth defects, and mothers' medical conditions. In all, 69 percent of mothers had used oral contraceptives, but stopped more than three months before pregnancy, and 21 percent had never used them. Eight percent of the women had stopped using oral contraceptives within three months of conception, and 1 percent used them after getting pregnant.
Among 880,694 births, 2.5 percent of the babies had a birth defect such as a cleft palate or an arm or leg defect, the researchers found. Specifically, Charlton's team found that for every 1,000 births, 25.1 infants of mothers who never used oral contraceptives had birth defects, as did 25.0 of infants of mothers who had used oral contraceptives more than three months before pregnancy. The rate was 24.9 among mothers who used oral contraceptives within three months of becoming pregnant, and 24.8 among mothers who used oral contraceptives before realizing they were pregnant.
"The prevalence of birth defects was consistent across each of the oral contraceptive groups as well as when we added in pregnancies that ended as stillbirths or induced abortions," Charlton told HealthDay. "Similarly, the results were also consistent even when we broke down the birth defects into different subgroups, like limb defects."