[Oral contraceptives and elective surgery. Strategies in Norwegian hospitals, thromboembolic complications and perioperative conception].

It is widely accepted that treatment with combined oral contraceptives may increase the risk of venous thromboembolism perioperatively. Serious adverse effects such as allergic reactions or bleeding may result from thromboprophylaxis, while stopping the pill may lead to unwanted pregnancy. The objectives of this study were to examine how women on oral contraceptives were treated in Norwegian hospitals in relation to elective surgery, the number of spontaneously reported adverse drug reactions related to thromboprophylaxis, the number of diagnoses of venous thrombo-embolism combined with elective surgery in Norwegian hospitals, and the pregnancy rate in the perioperative pill-free period in this group of women. The study showed that Norwegian hospitals treated women on oral contraceptives in accordance with widely accepted guidelines. No serious adverse drug reactions related to thromboprophylaxis were found, and the frequency of venous thromboembolism in relation to elective surgery seemed to be remarkably small. The pregnancy rate in a perioperative pill-free period appeared to be low, since the women resumed contraception relatively soon after their first postoperative menstrual cycle. It is concluded that the procedures applied in Norwegian hospitals in 1989-90 were safe for this group of patients.