Changes in circulating alphafetoprotein following administration of mifepristone in first trimester pregnancy.

The occurrence of fetomaternal haemorrhage was investigated in 30 women by measuring maternal serum alphafetoprotein (AFP) levels before and after the administration of mifepristone (RU 486) for termination of first trimester pregnancy. A significant rise in AFP levels was seen in 21 women (70%), the increase ranging from 6 to 660% of baseline levels. The apparent frequency of fetomaternal haemorrhage was similar to that reported previously for surgical termination of first trimester pregnancies.