Effects of luteectomy and progesterone replacement therapy in early pregnant patients

The effect of luteectomy on the subsequent course of early pregnancy has been further investigated. In patients undergoing tubal ligation, comparisons have been made among those subjected to luteectomy and those receiving progesterone substitution therapy together with luteectomy. Patients exposed to only tubal ligation showed no significant differences from normal pregnant patients in plasma estradiol-17β and progesterone levels and in intrauterine pressure and oxytocin response. In luteectomized patients whose estradiol-17β and progesterone levels decreased markedly and continuously, intrauterine pressure and oxytocin response evolved after operation and abortion occurred. In those patients failing to show a continuous decline in plasma progesterone, only a partial evolution of intrauterine pressure and oxytocin response was evident, and clinical progress proceeded only to incipient abortion. Luteectomized patients treated with progesterone exhibited elevated progesterone and only a slight and transient decline in estradiol-17β levels and no evolution of intrauterine pressure and oxytocin response; normal pregnancy was sustained. Five patients of the 24 studied possessed “corpora accessoria” which were also removed. It is concluded that the evolution of intrauterine pressure and oxytocin response culminating in abortion can be provoked during early pregnancy by luteectomy-induced progesterone withdrawal which only occurs prior to an advanced luteoplacental shift in the site of progesterone synthesis. Progesterone substitution therapy prevented the consequences ascribed to luteectomy.