Method of endoscopy in the chimpanzee: relations of ovarian anatomy, endometrial histology and sexual swelling

Endoscopy was performed on adult female chimpanzees at various intervals before and after detumescence of the sexual swelling. The method required inhalation anesthesia, Trendelenberg positioning, abdominal insufflation with CO₂ and a 10 mm photo-endoscope inserted infra-umbilically. Accessory instruments were introduced into each of the lower quadrants. Mechanical ventilation and careful physiologic monitoring were necessary to control cardiac arrhythmias. Before detumescence of the swelling, unovulated follicles were observed. Immediately after detumescence of the swelling began, ovulated follicles or early corpora lutea were present. Secretory endometria and plasma progesterone values in excess of 4.0 mg/ml did not occur until three days after detumescence of the sexual swelling commenced. Endoscopic ovarian visualization offers a means of establishing accurate correlations between ovarian morphology and other parameter in chimpanzee menstrual cycles. The data presented support the interpretation that in this species, ovulation and sexual swelling detumescence are closely related in time.