Oral contraceptives and hepatitis. A report from the Boston Collaborative Drug Surveillance Program, Boston University Medical Center.

History of oral-contraceptive use was compared between 68 women with a hospital-discharge diagnosis of acute hepatitis and 1142 women who had been admitted for other reasons to the same hospitals during the same period. The risk of admission to hospital for hepatitis for users of oral contraceptives was estimated to be 3-3 times that for non-users (95% confidence interval, 1-8--6-3). This overall association was almost entirely attributable to a strong association among women under 25 years of age. Among users of oral contraceptives, duration of use tended to be shorter for hepatitis patients than for controls.