The role of oral contraceptives as a triggering factor for thrombosis in patients with lupus anticoagulant (LA) and/or anticardiolipin antibodies (ACA) has not yet been established. We describe the cases of three women aged 19, 29 and 48 years who developed venous thrombosis after 16 +/- 3.4 (mean +/- SD) cycles of oral contraceptives. They were all asymptomatic before taking the pill. Two patients subsequently developed venous and/or arterial recurrence of thrombosis. Laboratory studies performed after the diagnosis of thrombosis, showed the presence of LA and elevated levels of ACA (IgG and IgM) in all three patients. None of these patients had autoimmune diseases and therefore appeared to have a primary antiphospholipid antibody syndrome. The three patients belonged to a group of 45 young females who experienced their first thrombotic event while taking the pill. This group had a similar prevalence (8%) for antithrombin deficiency and antiphospholipid antibodies. We surmise that some of the women who developed venous thrombosis while taking the pill might have an undetected primary antiphospholipid syndrome.
PIP: In Italy, the University of Padua Hospital has treated 45 women for venous and/or arterial thrombosis during oral contraceptive (OC) therapy. Among the 38 who had no other risk factors for thrombosis, 8% had antiphospholipid antibodies. 3 patients featured in the cases were asymptomatic before beginning OC use. All 3 had their first thrombotic event during OC use. They developed thrombosis after 16 cycles of OCs. The first case (age 19) developed thrombotic occlusion on the left side of her body, especially her left leg after about 18 cycles of OC use (0.03 mg ethinyl estradiol and 0.075 mg gestodene). One month after beginning oral anticoagulant therapy physicians found antiphospholipid antibodies (i.e., the presence of lupus anticoagulant and increased levels of anticardiolipin antibodies). She later developed other thrombotic events despite anticoagulant therapy. The second case (age 35) first experienced a thrombotic event at the age of 29 after about 18 cycles of a sequential 3-phase combined OC. She was not put on long-term anticoagulant therapy at the time. 2 years later, she again experienced thrombosis in the same leg. She was put on oral anticoagulant therapy until age 33, when she wanted to become pregnant. She was then put on acenocumarol therapy. Her pregnancy ended in miscarriage at 8-10 weeks gestation. She developed thrombosis in the left leg 6 months later. Hospital staff detected antiphospholipid antibodies. Case 3 (age 48) had had 2 full-term, normal pregnancies and no miscarriages. She developed thrombosis in the left leg after 12 cycles of OC use (0.03 mg ethinyl estradiol and 0.075 mg gestodene). She discontinued OC use and began anticoagulant therapy. Laboratory findings indicated antiphospholipid antibodies. All 3 cases had or had had a false positive reading for syphilis. They were diagnosed with primary antiphospholipid syndrome (PAPS). These findings suggest that normal women who develop thrombosis during OC use might have undetected PAPS.