The recovery of normal plasma progesterone levels in the postpartum female

The return of fertility in postpartum women is gradual. This may be related to ovarian hormonal deficiencies, in particular, inadequate stimulation of the endometrium by progesterone (P). The purpose of this study was to evaluate the recovery of normal luteal function in four postpartum women who were followed for four cycles with serum P, follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and prolactin (PRL) taken three times weekly. PRL decreased immediately after delivery and was at normal levels before the first cyclic increases in serum LH and P. E2 and FSH cyclic changes were identical over the four menstrual cycles. LH peak values rose consistently from the first to the fourth cycle. P increased statistically each subsequent cycle in all parameters studied. These parameters of P were peak levels, days to the peak, duration of the luteal phase, and area under the P curve. The postpartum woman thus seems an excellent model for the study of ovarian hormonal disorders, particularly as they relate to disordered luteal P.