The list of things that can cause infertility seem endless. Nevertheless, one single factor does play a highly significant role in female fertility and infertility - her age.

 

Understanding why and how age affects infertility can help you decide if you want to delay having a child, or if you're already having difficulty with conception, why age is playing a part in your difficulties.

Pregnancy Rates and Age

Pregnancy rates of women at various ages have been studied for years. If you're not aware of the data, you should understand what the evidence says about pregnancy trends in women as they age.

Beginning in your early 30's pregnancy rates begin to decline, taking a sharp turn downward around age 35 and continue downward even faster through 40. Pregnancy occurs less and less after 40, with very few pregnancies recorded after age 45. The difference between couples in their early thirties compared to those at 40 are startling. When a woman is 30, just 7% of couples are infertile; by 40 that number grows to 33% of all couples infertile.

Why does this happen? What factors are contributing to this loss of fertility as a woman ages?

Age Related Declines In Fertility: Egg Quantity & Quantity

Egg quality refers to how able your eggs are to become fertilized. Every woman is born with a certain number of eggs in her ovaries, ready to be released for fertilization and pregnancy in her reproductive years. Egg quantity refers to the number of eggs that you have in your ovaries. At birth women have about 2,000,000 eggs and by puberty just 400,000; some will mature and be released in ovulation, many are lost daily in the process. Even when we are young, only a minority of these total eggs will be of good enough quality for fertilization. That's because for fertilization to occur, the egg must have the proper number of healthy chromosomes in order to develop into an embryo and, eventually, a baby. They also need to be able to combine with sperm in order to produce a child.

The quality of our eggs declines as we age. They become weaker, and less able to form a healthy embryo. They also begin to decrease in number of potential available each month (fewer antral follicles), which leaves fewer and fewer quality eggs available for fertilization. A 40 year-old woman usually has fewer eggs, and eggs of lower quality than a woman who is 20 years old. This is not to say that your eggs are of poor quality just because you're older. Some younger women will have poor quality eggs, just as some older women will have very high quality eggs. On average, however, egg quality does decline with age.

What Happens When Egg Quality & Quantity Declines?

Fewer eggs coupled with a higher percentage of eggs with poor quality can lead to:

• unexplained infertility
• IUI failure
• IVF failure
• repeated miscarriages
• chromosomal abnormalities

Can You Test Egg Quality Or Quantity?

If you are having troubles conceiving there are tests available that can help determine the quantity of eggs you have remaining in your ovaries. This is called ovarian reserve testing and typically involves a Day 3 FSH test. A Day 3 FSH test measures the level of follicle stimulating hormone (FSH) in your blood on day three of your menstrual cycle. When you have many eggs you release less FSH to recruit an egg each month, but as we age, more is needed to recruit an egg for development and ovulation.

The test can offer some insight into how many eggs you have in your ovarian reserve by indicating how much FSH you are releasing to stimulate your ovaries to stimulate an egg to mature each month. When levels are higher than 10, this indicates that you have fewer good eggs to recruit, so your body is releasing more hormone to so that an egg can be matured for release. FSH levels greater than 13 IU/L are generally very unfavorable.

Treating Age Related Infertility

If you are having difficulties getting pregnant, and learn it is due to the aging process, you do have some options.

Fertility drugs can help to increase the number of eggs that your ovaries release every month, which can help increase your chances of releasing a good one and becoming pregnant. There are a wide variety of fertility drugs available, one commonly prescribed medication is clomiphene, which stimulates the development of multiple eggs each month. The stronger injectables (hFSH, gonadotropins) are generally the drugs of first choice for older women, however.

In-vitro fertilization (IVF) may be an option to help retrieve more viable eggs from your ovaries with high doses of injectable medications. In this way, you may be able to maximize the number of embryos possible, giving you the best chance that a healthy one will be created and made available for transfer back into you.