In many cases, chemotherapy treatments leave patients sterile or with reproductive disorders. Classically, doctors suggest that patients take eggs before treatment and then have them mature. in vitro and freeze them for later use. Until now, no pregnancy has been able to be triggered through this process, failures being systematic. But as part of a world first, a woman cured of cancer had successfully completed a pregnancy started with a frozen egg several years earlier. A success of a team of French researchers considered as a real medical breakthrough by the scientific community.
A woman made sterile by cancer treatment gave birth after one of her immature eggs matured, was frozen and – five years later – thawed and fertilized. The study, published in the journal Annals of Oncology describes how the baby was born to a 34-year-old French woman who had been undergoing chemotherapy for breast cancer.
Maturation in vitro and freezing: functional eggs several years later
Before treatment started, doctors removed seven immature eggs from her ovaries and used a technique called maturation. in vitro (IVM) to allow the eggs to develop further in the laboratory. To date, there have been no successful pregnancies in cancer patients with eggs who have undergone IVM and freezing. However, some children were born following an IVM immediately followed by fertilization and transfer to the patient.
Michael Grynberg, head of the Department of Reproductive Medicine and Fertility Preservation at Antoine Beclère University Hospital near Paris, recalled learning about the case of a 29-year-old patient. ” I offered him the opportunity to freeze the eggs after IVM, as well as freeze the ovarian tissue “. The patient rejected the second option as being too invasive just days after the diagnosis of cancer.
Infographic describing the procedure used by doctors. Credits: M. Grynberg et al. 2020
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Cryopreservation of ovarian tissue is an experimental method in which the outer layer of an ovary – which contains immature eggs – is removed from the body and frozen for future use. In the case of the French patient, the ultrasound revealed that there were 17 small bags filled with fluid containing immature eggs in her ovaries. But using hormones to stimulate the ovaries and ripen the eggs would have taken too long and could have made her cancer worse, leaving the recovery of immature eggs and freezing as the best option.
Towards an optimized and less invasive in vitro fertilization procedure
” The freezing technique without stimulation (hormonal) works less well, but in this case, we really had no choice Says Grynberg. After five years, the patient recovered from breast cancer, but was unable to conceive naturally. Chemotherapy had made her sterile. After the age of 40, about 40% of breast cancer patients go through menopause because of their treatment. At 30, the rate is 15 to 20%.
On the same subject: First worldwide case of semi-identical twins identified during pregnancy
Six of the eggs that had been frozen five years earlier survived the thawing process and five were successfully fertilized. One of these fertilized eggs was transferred to the patient’s womb, which gave birth to a healthy baby boy named Jules on July 6, 2019.
” We have shown that this technique, even if it can be improved, allows women in this situation to have children. Says Grynberg. Freezing eggs at this stage also means that they remain the property of the woman, without the complications of using a partner’s sperm to fertilize. ” This advance is particularly important for cancer patients, but it is also a step towards easier and less invasive in vitro fertilization (IVF). “, Conclude the authors.
Sources: Annals of Oncology
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