Oral anticoagulation therapy during pregnancy in patients with mechanical mitral valves: a prospective study

Reports on phenindione toxicity have limited its use as an oral anticoagula nt. Our aim was to evaluate its risks in pregnant women. Thirty-one pregnan cies in 29 women with mitral ( aortic) St. Jude mechanical valves were foll owed-up prospectively. Eighteen patients received phenindione. Eleven patie nts (37.9%) received in addition to phenindione 225 mg dipyridamole, which was given in three doses. The target INR was 2.5-3.5 in the former and 2-2. 5 in the latter treatment. A fortnight before delivery, intravenous heparin otherapy was substituted. There were no maternal complications, apart from a single postpartum hemorrhage (3.2%). After the deliveries the results wer e: 26 mature babies (83.9%), 3 premature babies (9.7%) and 2 cases of still birth (6.4%). Outcome was dose related; being 57.2 +/- 20.9 mg/day for matu re babies and 82.5 +/- 11.2 mg/day for prematures and stillbirths (P = 0.01 6). Phenindione provided safe and effective anticoagulation during pregnanc y. A larger study is necessary to confirm the relationship between the dosa ge and outcome. (C) 2001 The International Society for Cardiovascular Surge ry. Published by Elsevier Science Ltd. All rights reserved.