New hope is on the horizon for women who face sterilization from cancer treatments. A woman in Canada has given birth to the first baby who was created from an egg matured in a laboratory, frozen, thawed, and then fertilized.
The baby girl was born to a woman diagnosed with advanced ovarian disease. Three other members of the 20-person trial group are also pregnant via this technique.
The trial group, whose average age was about 30, had all been diagnosed by ultrasound with polycystic ovarian syndrome (pcos), a fertility threatening hormonal disorder that affects about 10 percent of all women in the child-bearing years.
A total of 296 eggs were collected from the patients, 290 of which were immature. These eggs were then matured in the laboratory for 24-48 hours, frozen for several months and then thawed. 148 of the eggs survived the thawing process and were fertilised by a technique called intra-cytoplasmic sperm injection. 64 embryos were then transferred to the women. In order to boost the chance of pregnancy, they received multiple embryos.
According to Hananel Holzer, who led the team from the McGill Reproductive Center in Montreal, the success of this procedure has progressively increased. 3 of the last 5 patients have become pregnant as a result.
This technique differs from that which is already employed by doctors which envolves ovarian stimulation by hormones to obtain the eggs and fertilise them before freezing. The Canadian team collected hormones from unstimulated ovaries, and fertilisation occurred after the egg had been frozen and thawed.
“Until now, it was not known whether oocytes (human eggs) collected from unstimulated ovaries, matured in vitro and then vitrified could survive thawing, be fertilised successfully and result in a viable pregnancy after embryo transfer,” said Holzer
However, the procedure is still very much in the research phase. It has not yet been proven in cancer patients, it’s biggest potential beneficiaries.
If this procedure continues to be successful, it will be a good alternative to the tissue implantation that is only option for cancer patients who did not have time to have their ovaries stimulated for harvesting. It also provides women infertile with PCOS, who could have potentially fatal overstimulation from the hormone treatments, a chance at motherhood.
Obtaining immature eggs from unstimulated ovaries and coaxing them toward pregnancy, is a major step forward for patients this group.
Also reported at the annual conference of the European Society of Human Reproduction and Embryology (ESHRE)
Scientists in Isreal have been able to obtain and freeze eggs from the ovarian tissue of girls as young as five years old.
Childhood cancers usually result in cure rates of between 70 and 90 percent, but sometimes this comes at the cost of inflicting sterility when the child reaches adult life.
Obstetrician Ariel Revel of the Hadassah University Hospital, Jerusalem, found eggs in the ovarian buds of pre-pubescent girls aged between five and 10 years. The eggs were gently sucked out using a needle, were matured in a lab dish and then frozen, for potential use in the future.