Trying To Conceive At The Age Of 35 And Beyond
Trying To Conceive At The Age Of 35 And Beyond
MIDDLE age has never been accepted as one of the best times to conceive but experience shows that it is quite possible to achieve successful pregnancies either through natural or assisted fertility treatment procedures up to the age of 35 and even beyond. There are many available options to chose from, but In-vitro-fertilization (IVF) appears to be proving most popular.
Once you have become familiar with the available procedures, it is important to know that pregnancy and birth rates for women over 40 years of age who undergo IVF and other assisted reproductive techniques are generally lower than those for younger women. This is not to imply however that an older woman cannot achieve pregnancy with this procedure. It is more appropriate to say that the likelihood of successful pregnancy for such woman is lower compared to a younger woman who is less than 35 years of age. Many primary factors are responsible for this outcome and we shall address each of these in turn.
One of the reproductive factors specific to older women who are trying to conceive is the quality of eggs which declines with advancing age. It is believed that one of the most common reasons that women over the age of 40 years have a lower success rate following IVF is related to aging of the woman’s eggs. Generally in women less than 35 years of age, approximately four out of every five eggs that are produced are healthy and have the potential to be fertilized. At 45 however, the reverse is usually the case with many of a woman’s egg being defective. This has been attributed to the effect of age on the chromosomes. The most rapid decline in egg quality occurs after the age of 40 years. Because egg quality declines dramatically with age, it is common to transfer a greater number of embryos to the uterus of an older woman in the hope of offsetting embryo quality problems. This generally does not increase the risk of multiple births.
The next factor has to do with the fact that women aged 35 and over are more resistant to stimulation with fertility medications. It is like this: the older a woman becomes, the closer she gets to the change of life (best known as the menopause) and the more resistant her ovaries become to hormones that stimulate ovulation. It is for this reason that women over the age of 40 commonly experience abnormal ovulation. It also explains why older women find it more difficult to conceive naturally. Added to this is the development of increasing resistance to fertility hormones, making it much more difficult for the production of multiple follicles. This is important because the ability to induce the development of multiple follicles is essential for harvesting multiple eggs for IVF.
With today’s technology, it is possible to assess the sensitivity of a woman’s ovaries to fertility drugs by measuring the follicle stimulating hormone (FSH) and estradiol blood levels in a cycle preceding an IVF cycle. The levels of these parameters help to determine the most ideal dosage and regimen of fertility drugs necessary to achieve an optimal response. What gives indication of an optimal response is the result in production of the maximum number of follicles containing eggs in the ovary. Unfortunately, advanced age affects the potential for egg production (even with the use of fertility drugs) in any given cycle. When fewer eggs are available for retrieval, fewer embryos can be transferred back into a woman’s uterus. Transferring fewer embryos can impact the likelihood of a successful outcome (pregnancy).
Another factor is that older women are more predisposed to miscarriage and birth defects. With advanced age comes an increased incidence of chromosomal deformities in a woman’s eggs. We have established that a woman is producing fewer and fewer eggs as she ages, but it is also significant to note that the quality of those eggs deteriorate as well. These chromosomally defective eggs, when fertilized naturally or through IVF, are much less likely to implant properly or be successfully carried to term. Miscarriage is often the result. It is quite rare that these aberrant fertilized eggs implant successfully and the fetus carried to term, however the result may be a baby with a birth defect such as Down’s syndrome.
There are other risk factors to conceiving in addition to age. Just like in younger counterparts, women above 35 may have other risk factors for infertility including pelvic disease, endometriosis or uterine fibroids. Unfortunately, these are conditions which may further compromise the ability to achieve pregnancy either naturally or with IVF, in addition to declining egg quantity and quality.
Even as much as we have talked about the effect of advancing age on a woman’s fertility, it is significant to note that sperm quality still matters. To be exact, sperm quality is a major factor which influences the likelihood that eggs will be successfully fertilized. Accordingly, poor sperm function will negatively influence the number of embryos that are available for transfer to the uterus. The bottom line is that while sperm quality is independent of the woman’s age, it is nevertheless very important.
Cost of treatment
Cost of treatment also cannot be overlooked. By all standards, the cost of IVF treatment is likely to be greater for older women probably women because reduced success rates and higher miscarriage rates in these women inevitably require more IVF cycles. This burden is usually borne by the infertile couple as there are no immediately available health plans for the reimbursement of the cost of IVF or related procedures.
Although success rates for ART using donor eggs with those for ART using a woman’s own eggs among women of different ages indicate that the likelihood of a fertilized egg implanting is related to the age of the woman who produces the egg, it becomes obvious that the rate for cycles using embryos from a woman’s own eggs declines steadily with age. In addition, a woman’s chances of success using ART (with her own eggs) decrease at every stage of ART as her age increases.
Age-related causes of infertility are not always insurmountable. Just because a woman is over 40 does not mean she cannot conceive, however all the above factors need to be weighed carefully prior to proceeding with the IVF cycle. This is where the services of an experienced reproductive endocrinologist are invaluable to provide a guided pathway to parenthood. For those who decline to proceed with IVF or have repeated unsuccessful attempts, the option of third party parenting is always available