Abstract 2067: Clinical Study on Anticoagulation in Pregnant Women with Mechanical Heart Valves
Background: It is a challenge for women, who have received mechanical valve replacement, to become pregnant, to maintain pregnancy, and to deliver a healthy baby without any complications. In this study, we analyzed maternal and fetal effects of anticoagulants in pregnant women with mechanical heart valves.
Patients and Methods: From January 1980 to March 2005, fifty-nine pregnancies from 55 women with mechanical heart valves were followed up. Mean age at valve replacement was 22.7 years (range: 13~ 37 years), and mean age at pregnancy was 30.4 years (24 ~39 years). Forty patients (44 pregnancies) had taken Warfarin before recognizing their pregnancy, and 14 patients had planned pregnancy and had taken subcutaneous (SQ) heparin before pregnancy (HT). Among 40 patients (44 pregnancies), 22 patients (22 pregnancies) were changed to heparin as soon as they recognized their pregnancy (WH), and the other 20 patients (22 pregnancies) maintained Warfarin during pregnancy (WT). For patients who had planned pregnancy, heparin was administered by SQ injection as 12 hour intervals and aptt was checked 12 hours after each injection to achieve an aPTT range 2~3 times normal value. One patient did not take any anticoagulants throughout the pregnancy.
Results: Among fifty-nine pregnancies, 36 live birth deliveries (61%), and 23 fetal losses (39%) developed. In planned HT group (n=14), all patients delivered live births, and WH group delivered 18 live births (82%). In WT group, only 3 live births were delivered. Nineteen and 4 fetal losses occurred in WT and WH groups, respectively. Fetal complications developed in 5 babies (whole body petechiae;1, low birth weight or growth retardation;3, fetal distress;1). Maternal complications included whole body petechiae (1), bleeding during delivery (1), retroperitoneal hematoma (1), valve thrombosis (2), and osteoporosis (1).
Conclusions: We consider, that in the absence of a major complication, it is safer for both the mother and the fetus to maintain aPTT of 2 ~3 times normal adjusting the dose of SQ heparin as an optimal anticoagulant in pregnant women with a mechanical heart valve.