Four spontaneous pregnancies and three live births following subcutaneous transplantation of frozen banked ovarian tissue: what is the explanation?

OBJECTIVE

To report the long-term follow-up of an experimental heterotopic ovarian transplantation with frozen-thawed ovarian tissue.

DESIGN

Long-term follow-up of an experimental surgery; case report.

SETTING

Academic reproductive medicine center.

PATIENT(S): A 28-year-old cancer survivor with previous Hodgkin disease and relapse.

INTERVENTION(S): Laparoscopic oophorectomy for ovarian cryopreservation before preconditioning chemotherapy for hematologic stem cell transplantation. Ovarian tissue thawing and subcutaneous heterotopic ovarian transplantation in the lower abdominal wall 2½ years after the hematologic stem cell transplantation.

MAIN OUTCOME MEASURE(S): Resumption of ovarian function after transplantation, recovery of fertility, and pregnancy outcome.

RESULT(S): Follicle development was observed in the graft 2 months after transplantation, and a P value of 14 ng/mL indicated ovulation. The patient conceived spontaneously four times within 5 years and delivered three children. The in situ ovary remained atrophic but showed occasional follicle activity contemporaneously with the graft.

CONCLUSION(S): The mechanism behind spontaneous restoration of fertility with consecutive viable pregnancies after a heterotopic ovarian transplantation needs to be explored. Further laboratory and clinical research will be needed to explore the true origin of pregnancies after ovarian transplantations.