Fluctuations in anti-factor Xa levels with therapeutic enoxaparin anticoagulation in pregnancy.

OBJECTIVE: The objective of the study was to evaluate anti-factor Xa levels with therapeutic enoxaparin anticoagulation in pregnancy. STUDY DESIGN: A total of 15 pregnant subjects on therapeutic doses of enoxaparin (1 mg/kg +/-20% subcutaneously (s.c.) twice daily (b.i.d.)) were enrolled prospectively in this cross-sectional pilot project. Three blood levels for anti-factor Xa activity were examined: before the enoxaparin dose (trough), 3- to 4-h later (peak) and 8-h later. Anti-factor Xa activity level between 0.5 and 1.2 U/ml was considered therapeutic. RESULT: Mean anti-factor Xa activity levels were: trough 0.45+/-0.18, peak 0.9+/-0.25 and 8-h after dose 0.72+/-0.23 U/ml. All peak levels were therapeutic; 20% (3/15) of the 8 h and 73% (11/15) of the trough levels were sub-therapeutic. CONCLUSION: Trough and 8-h post-dose anti-factor Xa activity levels were sub-therapeutic in a substantial number of patients receiving a b.i.d. regimen of therapeutic enoxaparin.

Unstable angina during pregnancy in two patients with premature coronary atherosclerosis and aortic stenosis in association with familial hypercholesterolemia.

Obstructive atherosclerotic coronary artery disease is uncommon in women during childbearing age, and the occurrence of myocardial ischemia during pregnancy has therefore been anecdotal. Two young patients with premature coronary artery disease in association with familial hypercholestrolemia had unstable angina in the second trimester of pregnancy. Workup revealed coronary artery disease and aortic stenosis. One patient opted for abortion at the twentieth week of gestation, and the other decided to continue pregnancy and was delivered by cesarean at 28 weeks' gestation. Coronary artery bypass grafting was performed after pregnancy in both patients. In addition, one of the patients underwent aortic valve replacement, and other had replacement of the narrowed ascending aorta with uneventful recovery. Our report describes an uncommon presentation of unstable angina during pregnancy in 2 young women with premature coronary artery disease and aortic valvular and supravalvular stenosis as a result of familial hypercholesterolemia. The management of these conditions during pregnancy is influenced by the effects of available therapeutic modalities on both maternal and fetal outcome.