Hormone analytical and carrier protein alternations following administration of mifepristone (RU 486) for termination of early pregnancy

Outpatient terminations were performed on 50 biochemically confirmed pregnancies of 33 to 43 days amenorrhea with a single oral dose of 600 mg of mifepristone (RU 486). 37 women were randomly assigned to an additional endocrine investigation, comprising serum levels of beta hCG, progesterone (P), estradiol (E2), cortisol (C), sexual hormone binding globulin (SHBG), and cortisol binding globulin (CBG) on days 0 and 7 prior to and following the drug administration. Of these 37 patients, 30 experienced a complete expulsion of the uterine contents, 28 until day 7, 2 subjects on day 9 and 10, respectively. The remaining 7 women either showed an unaffected pregnancy or the symptoms of incomplete abortion, which made a surgical intervention necessary. In the successfully treated cases the levels of beta hCG, P and E2 decreased significantly, the nonresponders showed unchanged or even increasing hormone values. No significant changes of cortisol concentrations were found in the group of nonresponders, while the successful cases exhibited a slight elevation probably due to the abortion-associated processes. No considerable therapy-dependent differences were observed in the levels of SHBG. A small but significant decrease in the mean CBG value could be calculated in the group of responders.