Primary antiphospholipid syndrome in pregnancy: an analysis of outcome in a cohort of 33 women treated with a rigorous protocol.

ABSTRACT Early recurrent miscarriage, placental insufficiency, intrauterine growth restriction (IUGR), and late fetal death all are possible consequences of primary antiphospholipid syndrome (APS). The authors undertook a prospective study of how best to manage APS pregnancies in 33 affected women who were pregnant. Nearly 80% of patients had a history of pregnancy-related morbidity and 36% had had thrombotic events. Four very premature live-born infants had died. One third of women had had three or more consecutive first-trimester miscarriages. A first-trimester ultrasound study was done to confirm viability and for accurate dating. Uterine artery Doppler waveform studies were done at 20 and 24 weeks gestation, and growth scans at monthly intervals starting at 24 to 26 weeks. The timing of delivery was individualized. Induction was recommended at 38 to 40 weeks gestation, although pregnancies were allowed to go beyond this if there were no complications. Operative delivery was done on obstetric indications. Aspirin and low-molecular-weight (LMW) heparin were given until labor began or until the day before planned delivery. Women taking warfarin were admitted 10 to 14 days before planned delivery and converted to either full-dose LMW heparin or intravenous unfractionated heparin up to the time of delivery. LMW heparin was continued after delivery when there was a history of venous thrombosis. The live birth weight in this series was 91%; there were only three failed pregnancies. Mean birth weight was 2853 g, and mean gestational age was 36.7 weeks. Complications included four cases of IUGR (two with concurrent preeclampsia), transient ischemic attacks in five women receiving LMW heparin, and one case of placental abruption. Renal function declined in one patient who had glomerular thrombotic microangiopathy. Lupus anticoagulant was the strongest predictive factor for a thrombotic event in pregnancy. Levels of anticardiolipin antibody were less predictive, but a past thrombotic event was a strong risk factor. A history of IUGR or fetal death predicted IUGR in the current pregnancy. The operative delivery rate in this series was 59%. This study shows that a very high live birth rate is achievable in women with primary APS who have a history of significant pregnancy-related morbidity and/or thrombosis.