In recent years there has been an increased demand for fertility preservation. Nowadays, the development of advanced techniques in Assisted Reproduction enables the safe cryopreservation and storage of gametes in order to preserve their fertility for future use where and when required.
PRESERVING MALE FERTILITY
Freezing and thawing sperm has very good survival rates for sperm mobility and sperm fertilization. Also, cryopreservation of sperm is not related to the development of congenital or other embryonic abnormalities. The sperm can remain cryopreserved theoretically indefinitely and used in future IVF efforts. In particular, scientifically pregnancy has been recorded using cryopreserved sperm of twenty years (20 years).
Sperm freezing is recommended to:
- Adult men or teenagers who are about to undergo a cancer therapy (surgery, chemotherapy and radiation)
- Adult men or teenagers who are going to undergo any treatment that may affect their reproductive capacity
- Men to be subjected to surgery (prostate or testicular surgery)
- Men with exposure to chemicals, radiation or excessive heat that can cause infertility
- Male patients with previous medical history of oligoasthenospermia
In cases of azoospermia we attempt to retrieve a sperm sample surgically through the epididymis (PESA) or the testicular tissue (TESA)
PRESERVING FEMALE FERTILITY
The most common methods of preserving female fertility are:
Egg Cryopreservation
Keeping fertility through egg freezing is one of the biggest gains in IVF, allowing thousands of women around the world to become mothers when they want it.
As a method, egg cryopreservation is addressed to women:
- Who want to prolong their fertility for the distant future for educational, professional, economic or purely personal reasons
- Who have a family history of premature menopause
- Who have health problems and are about to undergo treatments that cause damage to their ovaries and their eggs (ovarian ablation, chemotherapy or radiation therapy in cases of cancer)
What does the procedure include?
The process of collecting eggs for cryopreservation is the same as for IVF after appropriate ovarian hormone stimulation. The eggs are then evaluated by the embryologists for their quality and maturity, prepared and frozen in liquid nitrogen containers (-196οC). When the woman wishes/can have a child, the eggs are thawed and fertilized in the laboratory and transferred to the womb as an embryos. When drug use is contraindicated, it is possible to collect eggs in a natural cycle or immature egg cells for women with polycystic ovaries.
What is the best age for egg cryopreservation?
The age at which a woman should choose this technique depends on many factors and is mainly related to the reasons why a woman wants to prolong her fertility. If we only assess medical factors, the answer is: the sooner the better. The ideal egg quality is observed in the 18th – 25th year of age.
Is the egg freezing safe?
The egg is the largest human cell and consists mainly of water and when it is cooled it forms crystals that can destroy it. With the vitrification method, however, it is achieved to freeze eggs with the highest survival rates to date.
More specifically, vitrification is the rapid cooling process of eggs using a high concentration of cryoprotectant. The result is a glass-like cell, which is free of crystalline form.
Approximately 95% of the eggs survive thawing, achieving fertilization rates, respectively, of fresh eggs.
Embryo Cryopreservation
The procedure is the same as the egg freezing, with the only difference being that the eggs that are taken are fertilized and frozen one or two days later. In comparison with egg freezing, embryo freezing has better thawing percentage and pregnancy achievement.
As a method embryo cryopreservation is addressed to women:
- Who are subjected to IVF and exhibit inappropriate endometrial function (e.g. with high hormone levels)
- With health problems and who are going to undergo treatments that cause damage to the ovary and may/wish to freeze embryos instead of freezing eggs
