Corpus luteum activity in tubal pregnancy.

Corpus luteum activity was monitored in 20 women undergoing nonsurgical management of ectopic pregnancy with methotrexate and citrovorum factor (N = 15) or observation (N = 5). The functional integrity of the corpus luteum was assessed by measuring progesterone and 17-hydroxyprogesterone. Trophoblastic viability was assessed by measuring the immunoreactive beta subunit of human chorionic gonadotropin. Ten of 15 methotrexate-treated patients demonstrated initial progesterone levels above 1.0 ng/mL, declining to levels below 1.0 ng/mL after treatment. Five of 15 methotrexate-treated patients and all five managed by observation alone demonstrated progesterone and 17-hydroxyprogesterone values below 1.0 ng/mL both initially and throughout the surveillance period, leading to resolution, indicating previous death of the corpus luteum. We conclude the following regarding ectopic pregnancy: 1) Corpus luteum function declines early in the biologic history of some gestations while persisting in others, and 2) corpus luteum function varies from active to inactive independent of serum levels of immunoreactive beta-human chorionic gonadotropin.