First ovulation after childbirth: the effect of breast-feeding.

Abstract The first postpartum ovulation was diagnosed by means of endometrial biopsy, basal body temperature, vaginal cytology, and cervical mucus in a group of 200 women. The date in which the first postpartum ovulation and the first menstrual flow occurred was analyzed against the nursing status. One hundred and seventy women underwent a natural evolution of nursing; 24 of them ovulated while on full nursing; 49, while on partial nursing; and 97, when nursing had been discontinued. In 30 women, nursing was artificially suspended immediately after delivery. No women ovulated before the thirty-sixth postpartum day in the entire study group. The intensity and length of nursing affected the date in which the first postpartum ovulation occurred. The first postpartum menstruation was ovulatory in 78 per cent of the patients. Twelve pregnancies started with the first postpartum ovulation. Our data indicate that besides the re-establishment of ovulation other factors could be involved in the recovery of fertility after childbirth.