Early endocrine events in induced pregnancies.

Progesterone (P) and human chorionic gonadotropin (beta-hCG) levels were measured randomly or serially in 141 single clinical intrauterine pregnancies resulting from treatment of infertility. Seventy (group I) were conceived during spontaneous cycles, 36 (group II) with clomiphene citrate, and 35 (group III) with menotropins (hMG). Each group was subdivided into subgroup A (normal pregnancies) and B (pregnancies ending in abortion). Thirteen percent of patients in group I aborted, 19% in group II, and 31% in group III (P less than .05). The overall mean (+/- SD) P level in group IA was 25.8 +/- 10.3 ng/mL and in group IB, 16.6 +/- 9.9 ng/mL (significantly lower, P less than .001); in group IIA the mean P level was 37.8 +/- 21.9 ng/mL and in group IIB, 22.9 +/- 17.9 ng/mL, again significantly lower (P less than .01). In subgroups IB and IIB, 11 of 16 patients showed early abnormal beta-hCG patterns; these findings suggest defective embryonic development and/or deficient corpus luteum function as the cause of abortion. There was no significant difference between mean P in group IIIA (71.1 +/- 43.7 ng/mL) and IIIB (75.7 +/- 55.9 ng/mL). In group IIIB, the mean "peak" P level of 101.1 +/- 73.6 ng/mL was followed by a mean "nadir" of 35.4 +/- 24.8 ng/mL at 6-9 weeks. In group IIIB, 7 of 11 patients showed normal beta-hCG patterns. Three patients with precipitous P decline aborted karyotypically normal fetuses in spite of normally rising beta-hCG levels and the presence of fetal cardiac activity.(ABSTRACT TRUNCATED AT 250 WORDS)