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

Egg Vitrification:

Egg/Embryo Formation:

  • Stage 1 and 2 followed by Egg Vitrification
    • COST = approx. R33,000
  • Stage 1-4 followed by Embryo Vitrification
    • COST = approx. R45,000

Cancer & Reproduction:

  • Ovarian failure occurs in a significant percentage of childhood cancer survivors
  • Early menopause occurs in up to 30% if chemotherapy and pelvic radiation is administered
  • Cancer treatment often involves the use of chemotherapy and radiotherapy which could irreversibly damage the function of the ovaries or sperm, so there is often minimal time to preserve fertility once a patient has been diagnosed with cancer. It is therefore important that fertility treatment be initialised as soon as the diagnosis is made
  • Many Oncologists are worried about the use of hormones in women with estrogen-dependent tumours, so treatment needs to be modified depending on the diagnosis
  • Fertility preservation, therefore, requires each patient’s case being monitored as a unique case, taking into account planned treatment, time available, patient’s age, specific disease diagnoses, partner availability, and cost
  • Age and estrogen dependence will also be a consideration

Fertility Preservation:

  • Your Fertility Specialist will ensure ovarian suppression during cancer treatment
  • Ovaries can be elevated out of the pelvis if necessary in cases where pelvic radiation will be taking place; this is a separate surgical procedure that is offered, if needed.

Freezing techniques offered:

  • Embryo Freezing
  • Oocyte or Egg Freezing
  • Ovarian Tissue Freezing
  • Sperm or Testicular Tissue Freezing

Other methods for preservation/restoration of fertility are:

  • Conservative surgery for suitable cancer diagnosis
  • Alternative therapy for certain cancers chemotherapy or radiotherapy can be avoided
  • Egg donation which has success rates of > 60%
  • Embryo donation from previously successful couples in IVF; it is essential to note that couples rarely donate embryos. However, it does happen.
  • Surrogacy
  • Adoption
  • Uterine Transplantation; in cases of uterine cancer, however, this treatment is only available in certain clinics around the world

Conclusion:

  • Egg Freezing is available and allows women to retain the ability to conceive later on in life
  • Women should discuss fertility preservation with their Fertility Specialists as well as with their friends and family when making their decision and spread the word
  • Women in their 30’s should start considering fertility preservation
  • The treatment of cancer in young women should include discussions around fertility preservation

 

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