Effect of 1st-trimester loss on restoration of the hypothalamic-pituitary-ovarian axis.

This randomized prospective study was conducted to determine the length of time required for re-establishment of the reproductive axis following a 1st-trimester spontaneous abortion. The spontaneous gonadotropin secretion was significantly depressed during the first menstrual cycle after pregnancy loss, while the estradiol levels had normalized. Provocative testing revealed blunted gonadotropin release in the first menstrual cycle with return to normal during the first menstrual cycle after a spontaneous abortion. Endometrial biopsy specimens were also abnormal during the first menstrual cycle with normal histological characteristics by the second menstrual cycle. Therefore, restoration of the hypothalamic-pituitary- ovarian axis after a 1st-trimester loss is achieved within two menstrual cycles, as determined by return of normal pituitary function.