Morphologically normal: transplanted ovary yields embryo.(News)

Researchers have created the first morphologically normal human embryo using an egg obtained from ovarian tissue that was transplanted heterotopically.

Although the embryo was subsequently transferred to the patient's uterus, the procedure did not result in pregnancy, said Dr. Kutluk Oktay and his associates at the Center for Reproductive Medicine and Infertility of New York Presbyterian Hospital-Weill Cornell Medical Center, New York.

Although the procedure is still experimental, the creation of a morphologically normal embryo from transplanted ovarian tissue represents a major step forward in the preservation of fertility for cancer patients, Dr. Oktay told this newspaper.

The patient in this case report was a 36-year-old breast cancer survivor who had one ovary removed and frozen at age 30 when her disease was diagnosed. Subsequent chemotherapy put her cancer in remission but also rendered her remaining ovary sterile.

Six years after the patient's ovary was removed, Dr. Oktay's team replaced her cryopreserved ovarian tissue, inserting it under the skin of her abdomen. The ovarian tissue began functioning about three months after the procedure. Follicles could be palpated beneath the skin and visualized on ultrasound, while estradiol concentrations rose and FSH levels fell.

Oocytes were then retrieved every month for 8 months, usually after ovarian stimulation. In total, 20 oocytes were retrieved, 8 of which were suitable for in vitro fertilization (IVF). The majority of these 8 oocytes were used in intracytoplasmic sperm injection (ICSI) procedures (Lancet 363 [9412]:837-40, 2004).

Dr. Oktay ...