Last week, we started a discussion on Fertility Preservation. We discussed the meaning, when it is recommended and fertility preserving options in males. This week, we will be concluding with fertility preservation in females and give advice on fertility preserving options for adolescents.
FERTILITY PRESERVATION IN FEMALES
Fertility preserving options in females includes:
- Embryo cryopreservation – Also known as embryo freezing, is the most common and effective way to preserve a female’s fertility. In this method, a medical professional surgically removes eggs from the ovaries. The eggs are then fertilized in a lab with sperm from her partner or a donor in a procedure known as In-vitro fertilization (IVF). The embryos that result are frozen and stored for future use. When the female is ready, the embryo is thawed and implanted into the uterus for maturation and birth. While this is the most common method of female fertility preservation, it is not available to pre-pubescent girls because they do not have mature eggs that can be fertilized. Furthermore, because this procedure needs a two-week period of hormonal stimulation for egg maturation, it is not suitable for female patients with cancers as a result of hormones such as breast or ovarian cancer, or those who cannot postpone cancer treatment. Research studies shows that embryos can survive the freezing and thawing process up to 90% of the time.
- Oocyte cryopreservation – This method is similar to embryo cryopreservation except that unfertilized eggs are frozen without fertilization and stored instead of embryos. In this method, the unfertilized eggs are extracted and frozen to preserve viability for future use. This preservative method is often suggested due to medical reasons, such as cancer in female patients. It is also used for elective fertility preservation in females who are not ready to become pregnant but are concerned about their decline in fertility as they get older. Oocyte cryopreservation is now regarded as a well-established technique for female fertility preservation. However, human eggs do not survive freezing as compared to human embryos.
- Ovarian tissue cryopreservation – Human ovarian tissue cryopreservation has been used successfully around the world to preserve fertility in female cancer patients and other pathologies where the patient is at increased risk of primary ovarian insufficiency. Most importantly, this technique may offer a method for preserving fertility in prepubescent girls. In this method, a portion of the ovary is removed, frozen, and stored until the treatment is completed. After that, the tissue is thawed and re-implanted. Strips of cortical ovarian tissue can also be cryopreserved, but they must be reintroduced into the body to allow the encapsulated immature follicles to mature. Furthermore, ovarian tissue is delicate under hard freezing conditions, and reintroducing it into the body may lead to reintroducing cancerous cells. Although in vitro maturation has been demonstrated experimentally, the technique is not yet clinically available. Cryopreserved ovarian tissue could be used to create oocytes capable of direct in vitro fertilization using this technique. Also, fertility preservation techniques, such as ovarian tissue or oocyte cryopreservation may be used to avoid infertility and birth defects caused by advanced maternal age.
- Gonadal shielding in females – This process is similar to male gonadal shielding. In this method, the amount of radiation exposure the gonads receive is reduced by aiming rays at a small area or covering the pelvic area with a lead shield.
- Ovarian transposition – In this method, a medical professional performs a minor surgery to reposition the ovaries and in some cases, the fallopian tubes in the pelvis so they are not in the radiation field when radiation is delivered to the pelvic area. After treatment, the ovaries are taken back to position in order to conceive. However, ovaries may not always be protected due to scatter radiation.
What can parents do to preserve the fertility of a child?
- Fertility should be discussed with children suffering from cancer as soon as they are old enough to understand it. The parents and child consent is always required before fertility preservation is done for the child.
- If your child has reached puberty, oocyte or sperm cryopreservation may be an option.
- Girls who have cancer before puberty can have their ovarian tissue cryopreserved while in boys who have cancer treatment before puberty, the testicular tissue is surgically removed and frozen. Also, gonadal shielding and ovarian transposition may be used to preserve fertility in children who have not reached puberty.
- Some of these options, such as sperm, oocyte, and embryo cryopreservation, are only available to puberty-aged males and females with mature sperm and eggs.
CONCLUSION
Fertility preservation is an optimal solution for couples or individuals who want to start a family but are not ready to do so. Fertility decreases rapidly as men and women mature. Medical conditions and treatments can also have an impact on fertility. However, female eggs or male sperm can be cryopreserved for future fertility options. It is advised that the earlier fertility is preserved, the greater chances of having children in the future.
