Fetal Risk Summary
Danaparoid is a low molecular weight heparinoid extracted from porcine mucosa. It has an average molecular weight of about 5500 (1). Reproduction studies in pregnant rats and rabbits have found no evidence of impaired fertility or fetal harm (1).
A 1991 report described the use of a low molecular weight heparinoid (Org-10172) in a woman at about 11 weeks’ gestation with lupus anticoagulant and a history of heparin-induced thrombocytopenia (2). She was initially treated with aspirin, prednisone, and the heparinoid at 750 U SC every 12 hours, then increased to 1500 Units every 12 hours. At 25 weeks’ gestation, the dose was increased to 1250 Units SC every 8 hours because of a suspected subclinical thrombotic event. Severe thrombocytopenia was diagnosed 4 days later and the heparinoid and aspirin discontinued and warfarin begun. Because of progressive growth retardation and increasing fetal distress, a cesarean section was performed at 28 weeks’ gestation with delivery of a 510-g male infant, who died of prematurity complications 2 days later. Approximately 30% of the placenta was found to be infarcted. This was the probable cause of the growth retardation, not the drugs.
Three other case reports involving four outcomes (one set of twins) have described the use of danaparoid in pregnancies complicated by heparin-induced thrombocytopenia (3,4 and 5). In each case, the platelet count normalized after initiation of danaparoid. No fetal or newborn complications attributable to danaparoid were noted, and there was no evidence of anti-Factor Xa activity in the cord blood samples.
Breast Feeding Summary
No reports describing the use of danaparoid during lactation or breast feeding have been located. Danaparoid has an average molecular weight of about 5500 and, as such, should not be expected to be excreted into human milk. Because the drug would be inactivated in the gastrointestinal tract, the risk to a nursing infant from ingestion of danaparoid from milk appears to be negligible.
- Product information. Orgaran. Organon, 1997.
- van Besien K, Hoffman R, Golichowski A. Pregnancy associated with lupus anticoagulant and heparin induced thrombocytopenia: management with a low molecular weight heparinoid. Thromb Res 1991;62:239.
- Henny ChP, ten Cate H, ten Cate JW, Prummel MF, Peters M, Buller HR. Thrombosis prophylaxis in an AT III deficient pregnant woman: application of a low molecular weight heparinoid. Thromb Haemost 1986;55:301.
- Greinacher A, Eckhardt Th, MuBmann J, Mueller-Eckhardt C. Pregnancy complicated by heparin associated thrombocytopenia: management by a prospectively in vitro selected heparinoid (ORG 10172). Thromb Res 1993;71:1236.
- Gill J, Kovacs MJ. Successful use of danaparoid in treatment of heparin-induced thrombocytopenia during twin pregnancy. Obstet Gynecol 1997;90:64850.