[Prenatal pharmacology of low molecular weight heparin and pentosan polysulfate]

The aim of prenatal pharmacology is to evaluate the biologic effects to the fetus of a drug taken during pregnancy. Development of a new technic for collection of fetal blood samples in utero under ultrasound guidance allowed, by evaluation of maternal and fetal hemostasis, study of two low molecular weight heparins, PK 10169 (Lovenox) (table I) and CY 216 (Fraxiparine) (tableau II) and of pentosan polysulfate (Hemoclar) (table III). Under the operating conditions applied, the three molecules failed to diffuse across placenta during 2nd and 3rd pregnancy trimesters. This permitted treatment of eleven women at risk for eclampsia or thromboembolism with good clinical results, white confirming absence of circulating heparinemia at birth (umbilical cord blood).