Normal pregnancies and live births after autograft of frozen-thawed hemi-ovaries into ewes.

OBJECTIVE To evaluate long-term outcome of autotransplantation of cryopreserved hemi-ovaries into ewes. DESIGN Animal study. SETTING University fertility center, Hospices Civils de Lyon; and Ecole Nationale Vétérinaire de Lyon. PATIENT(S) Grivette ewes. INTERVENTION(S) Six hemi-ovaries from 6 ewes aged 6 to 12 months were frozen with a slow cooling protocol using 2 M of dimethyl sulfoxide as cryoprotectant. After dissection of the medulla, the hemi-ovarian cortex was stored at -196 degrees C in liquid nitrogen. Freezing procedure was performed with a programmable freezer. Semiautomatic seeding was performed before crystallization. Four to 6 weeks after the first laparotomy, the left ovary was removed and the frozen-thawed hemi-ovary was sutured. MAIN OUTCOME MEASURE(S) Mean plasma concentrations of FSH, LH, and progesterone after autotransplantation of frozen-thawed hemi-ovary. Ultrasonography was done to confirm pregnancy. Blood samples were collected weekly to measure FSH, LH, and progesterone. After the first birth, the autografted ovary was removed for histologic examination. RESULT(S) Plasma progesterone concentration increased in a regular manner in all ewes except one 4 weeks after the graft. Concentrations of FSH and LH did not reach the menopausal level. Four pregnancies occurred, from which 6 lambs were born. The first delivery of a normal lamb occurred after 135 days of gestation; the lamb died immediately after birth. The second delivery of two normal lambs occurred after 130 days of gestation. A caesarean section was performed on the third pregnant ewe the 110th days of gestation because the ewe had a vaginal prolapsus. The two normal lambs and the ewe died after surgery. The fourth birth of a normal lamb occurred after 132 days of gestation. Histologic examination of the grafted frozen-thawed ovary showed a regressing corpus luteum and few primordial and antral follicles. CONCLUSION(S) These four pregnancies in a ewe model may indicate that women who undergo preservation of their ovaries before chemotherapy or radiotherapy can have successful pregnancy.