As we age, our bodies change, and our chances for pregnancy shift too. For those planning a family later in life, it’s important to consider the risks, quality, and trends that occur with age. Fertility drops more significantly in women after age 35 than they do with men. In this article, we’ll discuss reasons for reduced fertility, egg quality in older women, and risks associated with aging.
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Fertility Trends With Age
It’s normal (and expected) for fertility to begin decreasing with age; however, other factors come into play. Depending on the woman and her reproductive health, fertility will vary. Despite this, women over 35 years old are medically referred to as “advanced maternal age.”
Chances of Pregnancy
There’s a misconception that fertility ceases when menopause begins; However, fertility often begins to minimize significantly before menopause. In fact, chances of pregnancy will start to drop in a woman’s late twenties and will continue to decline into her thirties. For reference, on any given month with perfect timing of fertilization, a healthy 30-year-old woman has a 20% chance of getting pregnant. By the time a woman turns 40-years-old, her chances drop to 5%. This statistic shows the drastic decline of fertility in a 10-year period.
To understand the trends and chances of pregnancy, one must understand the reproductive system. At birth, a female is born with their maximum amount of eggs. By puberty, there are, on average, 300,000 eggs. The ovaries will house these eggs until menstruation begins, where one egg will be released monthly. This will continue until all of the eggs have been released. On average, a woman will release 300-400 healthy eggs throughout her lifetime.
Reasons of Reduced Fertility
Loss of ovarian reserve, or lack of egg quantity, and minimized egg quality are both to blame for reduced fertility. However, it doesn’t just stop there. Research has shown that as ovarian reserves begin to decrease, follicles may become less responsive to the follicle-stimulating hormone, or FSH. FSH has a vital role in fertility, as it assists eggs in maturing healthily and propels ovulation. Once the eggs stop responding to FSH, there is a lower chance of pregnancy occurring.
The quantity of eggs isn’t the only factor that plays into decreased fertility. In fact, the quality of eggs also decreases with age and results in a more challenging time getting pregnant.
Aneuploidy, a term that refers to irregular eggs that consist of too many or too few chromosomes, begins to occur in older women. A healthy egg should contain 23 chromosomes per egg to complement the 23 chromosomes that sperm holds. This will result in a healthy pregnancy of 46 chromosomes.
Risks of trisomy, which is an extra chromosome in a fertilized egg, jumps to 30% or more for women above age 39. This drastically conflicts the risk of trisomy in a 20-year-old pregnant woman, which is only 2-3%. Though many suggestions of why aneuploidy occurs in women over 35, there hasn’t been a direct understanding of this trend.
Depending on your reproductive health and other factors affecting pregnancy, a doctor may recommend different courses of action. When it comes to pregnancy later on in life, being proactive is a better option than being reactive.
For example, if you imagine that you’ll want to conceive one day, but you aren’t ready for it yet, you may consider freezing your fertilized eggs. This process extracts eggs in your healthiest and most fertile years, where they are tested for viability. If there’s a good chance that the egg will result in a healthy pregnancy, it will be frozen for the process of in-vitro fertilization down the road.
If you didn’t consider egg freezing earlier in life, you can use an embryo or egg donor. This process uses a healthy egg from a more fertile woman and uses sperm to fertilize the egg. With this option, the female patient can still carry and deliver the baby naturally.
The important thing to remember is that there are other options for pregnancy later in life. With medical advancements and supportive doctors, beginning a family is within reach despite reproductive age or associated concerns.
If you’re above age 35 and thinking about conceiving, it’s important to understand the associated risks and trends. Working alongside a practice of medical physicians trained to assist women with fertility concerns will present other options if you are unable to conceive.