Long-term follow-up of cryopreserved hemi-ovary autografts in ewes: pregnancies, births, and histologic assessment.

OBJECTIVE

To evaluate a 2-year follow-up of cryopreserved hemi-ovary autografts in ewes.

DESIGN

Animal study. SERTTING: University fertility center, Hospices Civils de Lyon; Ecole Nationale Vétérinaire de Lyon, INSERM U 418 Hocaron;pital Debrousse, Lyon; and Hôpital Edouard Herriot, Lyon, France.

PATIENT(S): Grivette ewes.

INTERVENTION(S): Recently we reported four pregnancies and six live births after transplantation of frozen-thawed hemi-ovary in six different ewes. The four remaining ewes were monitored for 2 years. After the last birth, the autografted ovary was removed in each ewe during a final laparotomy. The entire grafted ovary was sliced to estimate the remaining primordial follicle population 2 years after grafting.

MAIN OUTCOME MEASURE(S): Uterine ultrasound scanning was performed to diagnose pregnancy. Histological assessment of the grafted ovary was performed after delivery.

RESULT(S): The four remaining ewes began new gestations. For two of them, this was a second gestation obtained more than 2 years after the autograft. These two ewes delivered male lambs, which died immediately after delivery because of distocia. The lambs were both oversized for gestational age; autopsy found no malformation. A twin pregnancy of a healthy male and a healthy female occurred in May 2002, and a singleton male was born in February 2002. All grafted ovaries showed drastic reduction in follicle population.

CONCLUSION(S): Frozen-thawed ovary autograft allowed recovery of fertility a very long time after the procedure despite a drastic reduction in the total number of follicles.