Antiphospholipid antibodies in young women with and without oral contraceptive use

The role of thrombophilia in the elevated risk of thromboembolism during oral contraceptive use has been established. We performed a cross-sectional study among young women to survey the occurrence of antiphospholipid antibodies among users and non-users of oral contraceptives. Serum levels of immunoglobulin (Ig)G, IgA and IgM isotypes of anti-beta2-glycoprotein I and anticardiolipin antibodies were measured by validated enzyme-linked immunosorbent assay methods. Combining all types of antiphospholipid antibodies, pill-users had an elevated antibody titre more than twice as frequently as non-users (odds ratio, 2.3; 95% confidence interval, 1.1-5.1). The higher frequency of elevated antibody titre was related most commonly to IgG type anti-beta2-glycoprotein I antibodies. Oral contraceptive use increases the risk of elevated antiphospholipid antibody levels among asymptomatic young women.