Egg Vitrification & Oncofertility

By Dr. Olarogun

We were honoured to be a part of the first (and immensely successful) Fertility Show Africa exhibition that took place at Gallagher Estate in Gauteng in March 2020. One of our esteemed Reproductive Medicine Specialists, Dr. Olarogun, was invited to speak at the event as part of their expert panel. Dr Olarogun chose to discuss a fundamental matter of Egg Vitrification & Oncofertility. We decided it was important to share his findings with you.

What is Egg Vitrification and Oncofertility, exactly?

Definitions:

Egg Vitrification is a “flash-freezing” method in which oocytes are immersed directly into liquid nitrogen, cooling them rapidly to minus 196ºC so that they become “glass-like” or “vitrified”, allowing them to be stored for later use. Vitrification is completed nearly instantly, significantly reducing the chance of ice crystals forming and damaging the oocyte. With the vitrification process, preserved oocytes have the same viability as they did at the time of freezing.

Oncofertility is a field of medicine concerned with minimizing the adverse effects of cancer treatment (such as chemotherapy or radiation) on the reproductive system and fertility and with assisting individuals with reproductive impairments resulting from cancer therapy. Oncofertility procedures may include collecting and freezing eggs, sperm, testicular tissue or ovarian tissue before cancer treatment begins or using donor eggs or sperm when impaired fertility follows cancer treatment.

How Does Age Affect Fertility?

Women’s fertility, unfortunately, diminishes with age, which is accelerated from the age of 37
The above is due to a decrease in egg count and the quality of eggs
At birth, there are about 1-2 million eggs. This figure decreases to 200,000 at the onset of puberty

What Are Some Of The Causes Of Fertility Issues in Older Women?

Women are choosing to delay conceiving due to the need for professional achievements, higher education and the need for financial stability, before starting a family
By the age of 45, as many as 99 % of women are infertile
There is a higher rate of miscarriages in older women
The quality and quantity of eggs continue to decrease to a point where pregnancy is no longer possible
It is important to note that this process, is primarily related to ovarian function and not uterine function; so the uterus retains its ability to carry a pregnancy irrespective of age

Pregnancy Rates vs. Age in IVF:

What Is The Process Of Egg Freezing / Vitrification?

Egg Freezing/Vitrification is an established method of fertility preservation
Useful for women who do not want to create embryos; especially those who do not have a partner or do not, at this stage, want to use donor sperm
Freezing eggs has evolved from slow-freezing to vitrification; which is a quicker method, with better success rates
The probability of live births, following egg freezing, is more successful in women under the age of 35
The optimal age for egg freezing is, women between the ages of 30-35
If ten eggs are frozen for women aged between 30-37, the probability of achieving one live birth using the thawed eggs is between 60% -69% respectively

What Are The Important Factors To Consider When Freezing Eggs?

Age:

At the time of the procedure, age is a huge factor with regards to the probability of a successful pregnancy
Although we offer the service to women into their mid 40’s, success rates begin to deteriorate after the age of 42
We use state-of-the-art technology, however, women must have reasonable ovarian reserves to be considered for egg freezing
The expected or predicted child-bearing age must be taken into account, as the longer the interval or expected delay; the more beneficial this is to your Fertility Specialist in terms of planning ahead

Risk of Miscarriages:

Miscarriages later in life are when compared to miscarriage rates of naturally conceived pregnancies, a lot higher

Risk of the Procedure itself:

With Egg Vitrification, research has proven that there is no increased risk of congenital abnormalities or complications with the pregnancy; when compared to other fertility treatments, such as conventional IVF for example
Regrettably, rates of success are relatively low depending on the age of the patient; the older the patient, the lower the egg yield
Success rates are also lower depending on how many eggs are retrieved during the Egg Vitrification procedure; so if only 3-4 eggs are retrieved, the chances of success are not as good as if there are 8-10 egg retrieved

What Is the Step By Step Egg Freezing Process?

The patient will come in for a consultation with one of our Doctors. Included in the consult is:

An ultrasound scan
An ovarian reserve test
Counselling
The patient will start daily Gonadotrophins injections for 10-14 days
Your Doctor will monitor follicle growth with ultrasound, and hormonal assessments will be done every couple of days
Egg retrieval is done with the help of an ultrasound-guided needle under anaesthesia/sedation
Mature oocytes are frozen on the same day, and immature oocytes are checked on the following day and can be frozen if mature by then
There is evidence that if a high number of eggs are frozen, the better the chances are of a live-birth, so often two or more cycles will be done