Overweight and obese women who take oral contraceptives are 60 percent to 70 percent more likely to get pregnant while on the birth-control pill, respectively, than women of lower weight, according to new findings from Fred Hutchinson Cancer Research Center that will be published in the January issue of Obstetrics & Gynecology.
The study, led by epidemiologist Victoria Holt, Ph.D., M.P.H., a member of Fred Hutchinson's Public Health Sciences Division, is the largest case-control study of its kind to examine the link between body-mass index and oral-contraceptive failure. The research was conducted in collaboration with Delia Scholes, Ph.D., a senior investigator at the Center for Health Studies at Group Health Cooperative in Seattle.