Female fertility preservation is a method by which eggs, embryos or ovarian tissue of a female are preserved in a laboratory setting in order to use them during a later stage. This has become increasingly useful when dealing with fertility issues associated with certain illnesses like cancer. Radiotherapy or chemotherapy tend to cause irreversible damage to the ovaries, and thereby the non-fertilized eggs, which results in subfertility. With female fertility preservation, the eggs can be harvested before radiotherapy or chemotherapy is initiated and later on fertilized through IVF and subsequently introduced into the mothers’ uterus.
Egg freezing in female fertility preservation involves freezing the unfertilized eggs in liquid nitrogen. These eggs are collected by administering hormonal stimulation for a period of 10-12 days. Once harvested, the eggs are frozen and stored for use at a later stage.
With embryo freezing, the harvested eggs are fertilized using the male partner’s sperm via IVF. The fertilized embryo is then stored in liquid nitrogen and thawed whenever required.
Ovarian Tissue Freezing
A sample of ovarian tissue is harvested and stored in liquid nitrogen. It’s thawed out when needed and implanted in the female pelvis. After about 9 months, the implanted tissue begins to produce hormones and soon, follicles develop. With this technique, it’s possible to achieve pregnancy naturally rather than resorting to IVF. However, ovarian tissue freezing is still in the experimental stage and is not widely used in the mainstream.
Storage of Frozen Embryos
The harvested eggs are processed and labelled with the preserver’s details. The temperature of the eggs is then brought down to a level below the freezing point. The eggs are subsequently stored in a controlled environment under strict quality assurance guidelines which ensures their complete safety.
Freezing embryos places them into what can be best described as a deep sleep or hibernation state. The cellular activities are slowed down to such an extent that the cells go into stasis. Therefore the cells do not suffer damage due to the freezing as they are basically sleeping and inactive, so to say. The eggs thus stored are not used to perform any tests or research purposes; they are kept in a pristine condition to be used whenever required.
Benefits of Female Fertility Preservation
The reproductive system is severely affected as a result of cancers and subsequent treatment. Exposure to chemotherapy or radiotherapy can either cause subfertility, infertility or lead to mutations in the genes within the unfertilized eggs which can result in foetuses with genetic anomalies.
However, with the advent of female fertility preservation, women undergoing chemotherapy or radiotherapy can preserve their fertility for future needs.
Pregnancy after Fertility Preservation
The preserved eggs are thawed out when needed, fertilized through IVF, and then introduced into the woman’s uterus for implantation to occur. Frozen embryos can be directly placed in the uterus for implantation to proceed. Once implantation occurs, the pregnancy continues as usual. Regular follow-ups with the obstetrician ensure the pregnancy progresses normally.
The process of ovarian tissue sampling and preservation involves placing the ovarian tissue inside the female’s abdominal cavity. This is done with the hope that the ovarian tissue gets stimulated by the reproductive hormones and begins ovulating again. If ovulation takes place successfully, pregnancy can be achieved through timed intercourse or by using techniques like Intra Uterine Insemination (IUI) to fertilize the egg.