There has been a lot of information in the media regarding Egg freezing for women who don’t want to have a baby at the moment, or for those without a partner. Much of this information suggests that all women should freeze eggs, and the sooner, the better. So, what are the facts associated with this important issue?
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.
In the November edition of the Australian & New Zealand Journal of Obstetrics & Gynaecology, two articles were published regarding the Ethics of the restriction of access of women with a high BMI to Assisted Reproduction. The Royal Australian College of O&G, in its policies, says that having a BMI over 35 should be a complete barrier to having IVF. The Fertility Specialists at Ballarat IVF and South West Fertility do not support this position.
One of the articles argued that it is unethical to restrict access to services on the basis of BMI, and that all women should be provided with Fertility treatments, irrespective of their BMI. The second article looked at the topic from a different perspective. That is, from the view that women should be assisted to lose weight, and be made aware of the challenges, and relative risks involved with fertility treatment and pregnancy with a high BMI prior to embarking on assisted reproduction.
Strong arguments in favour of each position were presented. Looking at the factors in each argument which were agreed upon, of which there were many, the main ones were as follows:
1. Women who are of high BMI usually struggle to lose weight. There are a number of ways to tackle this important health issue, and some are more preferable to some women than others.
2. The more conservative the approach to weight loss taken, for example dietary modification, the slower it occurs. More radical approaches, such as gastric bypass surgery result in rapid weight loss, but do carry important risks in themselves, as well as the ideal (but not essential) requirement that a steady state of body weight be maintained for a period of time before trying for a pregnancy.
3. There are additional, well defined additional risks for women who undergo fertility treatments, and subsequently become pregnant, which include lower success rates for conception, and higher rates of adverse outcome in pregnancy, such as caesarean section, pregnancy loss, and pre-eclampsia
4. Despite these additional risks, the vast majority of women with a high BMI have an excellent outcome to their pregnancy, and in fact have better success rates for conception with Assisted Reproduction, when compared to other groups of women having Assisted reproduction. For example, a 35 year old woman with a BMI of 40 has a much higher likelihood of conceiving and having a healthy baby with IVF compared to a 42 year old woman with a BMI of 25.
So how do The Fertility Specialists at Ballarat IVF and South West Fertility provide advice to women of high BMI who wish to conceive?
As is the case with all of our patients, we take a personalized approach.
After undertaking a careful health assessment to exclude pre existing conditions, such as Hypertension, Diabetes, Kidney disease and heart problems, we work with our patients to formulate a treatment plan. The younger a woman is, and the higher her BMI, the more likely we are to advise dietary measures, or sometimes weight reduction surgery. Weight loss, even if 5%, has been shown to increase the chances of spontaneous pregnancy. Many women who are overweight have PCOS, so we work with you to treat this. The older a woman is, the less BMI influences her chances of conception. Above the age of 38, changing your BMI has virtually no positive effect on your chances of conception.
So, when caring for women, say over 36 with elevated BMI, much of the benefits of reducing BMI are centered on reducing the procedure based risks of IVF, if it is needed, and the pregnancy related risks.
Finally, after providing information regarding risks, and benefits, of all treatment options, including progression directly to IVF, we listen to, and will respect our patients plans and wishes for having a baby.
All the best