Firstly, there is no doubt that irrespective of how fertile a woman is, as she ages, her ability to conceive decreases. This is due to time related reduction in the quality of the eggs a woman produces, but also due to a reduction in her ovarian reserve. A reduction in ovarian reserve, generally speaking, means a reduction in the time until a woman becomes menopausal, and a reduction in the number of eggs she will produce during an IVF stimulation cycle.
Whilst it is an imperfect test, and can fluctuate, Anti Mullerian Hormone, (AMH), is a reasonable indicator of ovarian reserve. The baseline quality of a woman’s eggs, and hence her personal “level” of fertility, is mainly predetermined by genetic factors, which obviously can’t be changed. There are a number of factors, in addition to getting older which can adversely affect a woman’s ovarian reserve and AMH level. Lifestyle factors such as smoking, a poor diet, and having a high BMI adversely influence AMH.
Unfortunate situations, such as having endometriosis affecting the ovaries, having surgery for ovarian cysts, or having an ovary removed reduces AMH levels. If a woman has chemotherapy, this significantly reduces ovarian reserve, and a family history of early menopause is also a risk factor.
Some type of fertility preservation, either IVF with embryo freezing, or egg freezing is worth considering if you have any condition or situation which further reduces your ovarian reserve. That might include being at a certain age where there is little prospect, for a number of reasons, of having a baby in the near future.
The exact time for you to choose fertility preservation depends on a range of factors, and needs discussion with your fertility specialist. If you have obvious factors in your history which are likely to accelerate the normal decline in fertility, and ovarian reserve, the sooner you undertake fertility preservation, the better.
So how good is egg freezing for increasing the likelihood of having a baby? Well, it depends on the age at which it is done, and whether any of the above factors are present in a woman’s history. The older the woman, the more eggs she needs to have a good chance of having a baby. There is no guarantee.
For a 40 year old woman, she needs 15 eggs to have a 50% chance of a live birth AND 40 eggs for 80% chance live birth.
For a 37 year old woman, she needs 7 eggs to have a 50% chance of a live birth AND 20 eggs for 80% chance of live birth.
For a 30 year old woman, she needs 4 eggs to have a a 50% chance of live birth AND 12 eggs for 80% chance of live birth.
So, what does a woman who is thinking about fertility preservation do?
Firstly, consider whether you can alter lifestyle factors which adversely affect your fertility.
Next, if you have other risk factors for reduced fertility, consider having an AMH level performed, then speak to one of the Fertility Nurses or Specialists at Ballarat IVF or South West Fertility. You may need to consider egg freezing, but maybe not.