Spontaneous conceptions and live birth after heterotopic ovarian transplantation: is there a germline stem cell connection?

Ovarian cryopreservation and transplantation is an emerging technology to preserve fertility in women and children undergoing cancer treatment. Recent reports of live births after orthotopic transplantation raised hopes for the future success of this procedure. However, doubts remained whether the reported pregnancies were as a result of resumed function in the remaining ovary. We recently performed an autologous heterotopic ovarian transplantation in a 32-year-old Hodgkin lymphoma survivor who was menopausal for 2.5 years as a result of a preconditioning chemotherapy given before a hematopoietic stem cell transplant. Subsequent to the transplantation, the patient conceived twice within 3 months and delivered a healthy female child at 40 weeks of gestation. The occurrence of spontaneous pregnancies after heterotopic ovarian transplantation highlights the need for caution when interpreting the source of pregnancies in recipients with intact ovaries. On the other hand, the temporal relationship between the ovarian transplant and the spontaneous resumption of ovarian function and pregnancies in previously menopausal women is intriguing, especially in the light of recent reports of germ cell renewal and migration from the bone marrow to the ovary in rodents.