In vitro maturation and freezing: functional eggs several years later

Infographic describing the procedure used by doctors. Credits: M. Grynberg et al. 2020

Towards an optimized and less invasive in vitro fertilization procedure

Bibliography:



First birth achieved after fertility preservation using vitrification of in vitro matured oocytes in a woman with breast cancer’ by M Grynberg et al. was published in Annals of Oncology at 00:01 UK time on Wednesday 19th February.



DOI: https://doi.org/10.1016/j.annonc.2020.01.005

In many cases, chemotherapy treatments leave patients sterile or with reproductive disorders. Typically, doctors suggest that patients take eggs before treatment, then ripen them in vitro and freeze them for later use. Until now, no pregnancy had been able to be triggered via this process, the failures being systematic. But as part of a world first woman cured of cancer successfully carried out a pregnancy triggered via a frozen egg several years earlier. A success of a team of French researchers considered it as a real medical breakthrough by the scientific community.A woman made sterile by cancer treatment gave birth after one of her immature eggs was matured, 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 treated with chemotherapy for breast cancer.Before treatment started, doctors removed seven immature eggs from her ovaries and used a technique called in vitro maturation (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.Professor Michaël Grynberg, head of the Department of Reproductive Medicine and Fertility Preservation at the Antoine Béclère University Hospital, near Paris, France, is the first author of the letter.“I saw the 29-year-old patient following her diagnosis of cancer and provided fertility counselling. I offered her the option of egg freezing after IVM and also freezing ovarian tissue. She rejected the second option, which was considered too invasive a couple of days after cancer diagnosis.”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 liquid 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.After five years, the patient had recovered from breast cancer but found the chemotherapy had made her infertile as she had been unable to conceive within a year. Stimulating her ovaries to prompt them to produce more eggs ran the risk that the hormones used could cause the breast cancer to recur, so she and her doctors decided to use her frozen eggs. All six eggs survived the thawing process and they were fertilised using ICSI (intracytoplasmic sperm injection); five fertilised successfully and one embryo was transferred to the patient’s womb. She became pregnant and nine months later she gave birth to a healthy baby boy called Jules on 6 July 2019.Prof Grynberg said: “We were delighted that the patient became pregnant without any difficulty and successfully delivered a healthy baby at term. My team and I trusted that IVM could work when ovarian stimulation was not feasible. Therefore, we have accumulated lots of eggs that have been vitrified following IVM for cancer patients and we expected to be the first team to achieve a live birth this way. We continue offering IVM to our patients in combination with ovarian tissue cryopreservation when ovarian stimulation cannot be considered. This success represents a breakthrough in the field of fertility preservation.”He concluded: “Fertility preservation should always be considered as part of the treatment for young cancer patients. Egg or embryo vitrification after ovarian stimulation is still the most established and efficient option. However, for some patients, ovarian stimulation isn’t feasible due to the need for urgent cancer treatment or some other contraindication. In these situations, freezing ovarian tissue is an option but requires a laparoscopic procedure and, in addition, in some diseases it runs the risk of re-introducing malignant cells when the tissue is transplanted back into the patient.