in 23 pregnancies ( group i ) , the coumarin derivative acenocoumarol was discontinued and the patients received 5,000 u of subcutaneous heparin every 12 hours from the 6th to the 12th week of gestation , in 12 pregnancies ( group ii ) , heparin was not substituted for the coumarin derivative until after the 7th week , and in 37 pregnancies , detected after the first trimester ( group iii ) , the coumarin derivative was given throughout gestation .
C0032979
first
C0032961
gestation