What is Age-Related Fertility Decline?
Women are born with a set number of eggs and unlike men, they most likely don’t produce new ones throughout their life. The number of eggs is at its highest before birth, at around 20 weeks of pregnancy, and continues to decrease until about 32 years of age. After this point, the number of eggs declines at a faster rate, especially after 37 years of age.
As more American women focus on their careers and personal goals, the age of having their first child is becoming later. For example, between 1970 and 2002, the first childbirth for women over 30 increased six times. The number of women aged 30 to 34 giving birth to their first child grew by 28% between 2000 and 2014. At the same time, for women over 35, this number increased by 23%. As a result, fertility issues related to age are becoming more common.
It’s therefore important that healthcare professionals advise patients on the decline in fertility associated with age. It’s a crucial part of family planning. Doctors should educate patients about their potential fertility from an early age and refer them for further evaluation if needed. People often overestimate natural fertility and do not consider that delaying childbirth might lead to infertility.
Medical professionals should understand how fertility generally declines with age so they can properly advise their patients before fertility significantly decreases or is completely lost. Testing women for reduced ovarian reserves (number of eggs left) may be recommended for women 35 years or older who have been trying to conceive for 6 months without success. This age could be lower if a woman has a higher risk of reduced ovarian reserves, like having only one ovary, a history of ovarian surgery, exposure to chemotherapy or radiation, or unexplained infertility. For any patient aged 40 or older seeking infertility treatment, it would be appropriate to suggest an evaluation by a specialist in reproductive hormones. It’s important for the healthcare provider to discuss the decreasing chances of getting pregnant for patients in their 30s and 40s, the options for natural and assisted reproduction, and engage in shared decision-making as part of routine family planning counseling.
What Causes Age-Related Fertility Decline?
As women get older, their ability to have children decreases. This is primarily due to a decrease in the number and quality of their eggs. In the past, it was rare for women over 35 to be pregnant, but now it’s common for women of this age to have their first or second child. Unfortunately, fertility decline is a growing issue worldwide and isn’t always easy to solve, even with fertility treatment.
The number of eggs a woman has decreases over time in a process called atresia. For example, women have about 6 to 7 million eggs when they are 20 weeks into their mother’s pregnancy, but this declines to 1 to 2 million when they are born, 300,000 to 500,000 at puberty, 25,000 at age 37, and around 1,000 at age 51. By the age of 51, which is the average age of menopause for American women, the number of eggs has significantly declined. Unfortunately, there isn’t a known way to slow or reverse this decrease during the time leading up to menopause.
The quality of eggs is also key for successful fertility, and this declines with age too. Quality is related to the genetic makeup of the eggs. Unfortunately, as a woman ages, the chances for genetic abnormalities in the eggs, called aneuploidy, increase. This can significantly affect the quality of the eggs and a person’s fertility. In fact, aneuploidy is a common cause of miscarriage and infertility. Aneuploidy can be behind 65% to 75% of early pregnancy failures and roughly 35% of miscarriages that are officially recognised. By the age of 40, the risk of aneuploidy is 10 times higher compared to women younger than 25. The exact reasons why aneuploidy happens are unclear, but it’s likely related to age.
Risk Factors and Frequency for Age-Related Fertility Decline
The ability to have children varies from person to person and can depend on a wide range of factors. However, consistent patterns have emerged indicating that infertility is age-dependent. For instance, Japanese research noted that women aged 24 or younger had the highest chances of conceiving, but these chances decreased with age. Similar results were found in other research done on European women.
As people age, their overall likelihood of conception decreases. This decrease can be attributed to a variety of factors. With aging, people tend to have less sexual activity. Medical conditions and treatments, such as tubal diseases, leiomyomas, endometriosis, surgeries related to the ovaries or tubes, and chemotherapy, can also contribute to reduced fertility.
It is challenging to pinpoint age-based reasons for reduced fertility due to the many contributing factors. However, data from several trials on natural conception and in-vitro fertilization (IVF) suggest that both natural and assisted conception become less likely with increasing age. Therefore, it’s not surprising that 10% to 15% of couples trying to have a baby face fertility issues.
- The ability to have children varies greatly and depends on many factors.
- Age is a significant factor for fertility, with younger women generally having higher fertility rates.
- As age increases, fertility tends to decrease.
- Less sexual activity, health conditions, surgeries, and medical treatments such as chemotherapy also contribute to declining fertility
- Both natural and assisted conception are less successful with increasing age.
- About 10% to 15% of couples report difficulties in conceiving.
Signs and Symptoms of Age-Related Fertility Decline
Knowing whether fertility is decreasing is not straightforward based on medical history or physical checkups alone, except in the case of advancing age. Some women may have changes in their periods, like abnormal bleeding or having fewer periods, but these are usually related to nearing or being in menopause, rather than signifying reduced fertility. However, tests like lab work and ultrasounds can be helpful in investigating potential fertility problems.
Testing for Age-Related Fertility Decline
If you’re a woman over the age of 35 and have been trying to conceive for about six months without success, your doctor might suggest testing for diminished ovarian reserve (or lower-than-normal egg supply). The age at which this test is advised could be lowered if there are factors that increase the risk of having a reduced egg supply. These factors could include having only one ovary, a history of surgery on the ovaries, exposure to treatments like chemotherapy or radiation, and being unable to get pregnant without any clear explanation.
Women who are 40 or older and are having trouble getting pregnant should consider seeing a reproductive endocrinologist, who’s a doctor specializing in fertility issues.
It’s important to understand that while these tests can give an idea of how many eggs a woman has left, they can’t tell anything about the quality of the eggs. Moreover, these tests can suggest how the woman may respond to fertility medication. Studies have shown that women with fewer eggs tend to have lower chances of successful pregnancies through technologies that assist reproduction (like in vitro fertilization).
Right now, the best way to estimate the number of eggs a woman has left is by testing her level of a hormone called anti-müllerian hormone (AMH). This hormone is produced by the ovaries and its level tends to be related to the number of eggs a woman has available.
However, bear in mind that AMH levels start to decrease at about age 25 and can vary widely among women of the same age due to factors like ethnicity. Also, AMH levels can change by as much as around 21% based on the time of the menstrual cycle, and there’s no worldwide standard for measuring AMH. These uncertainties can make using AMH levels to assess egg supply in a specific woman less reliable.
Treatment Options for Age-Related Fertility Decline
Doctors specializing in women’s reproductive health have a crucial job in providing advice and connecting patients with fertility specialists. They should coach patients on how to improve their chances of getting pregnant, such as maintaining a healthy weight, lifestyle, and quitting smoking, reducing alcohol consumption. Regardless of whether a patient desires to get pregnant, it’s essential for doctors to educate about fertility issues and planning for a family. It’s also vital to discuss the challenges of getting pregnant naturally or through fertility treatments, especially for women in their 30s and 40s.
Many options exist to preserve a woman’s fertility using modern day freezing techniques. Freezing eggs, often termed “AGE-Banking,” is now a common approach to avoid fertility issues due to aging. After stimulating the ovaries and collecting around 15 eggs, a woman below 35 has around an 85% chance of eventually giving birth. Another, more invasive option, is the freezing of ovarian tissue. But for most women concerned about decreased fertility with age, freezing eggs is usually the top choice. Embryo freezing is less popular because issues over who legally owns the embryos can rise if the couple separates.
Most couples prefer to have a baby that shares their genetic material, but sometimes egg donation might be the best course of action. The risk of chromosomal abnormalities in the fertilized egg increases with the woman’s age. For instance, a woman over 42 years has an 85% risk of abnormality with IVF. To put things into perspective, a woman at 35 needs about five eggs to have a healthy embryo, while a woman over 42 may need 200. Older women also react less to the medication used to stimulate the ovaries. If the egg is from a donor, the success of IVF relies on the age of the donor, not the recipient. Thus, fertility specialists often suggest egg donation for patients who haven’t frozen their eggs, as donor eggs often lead to successful outcomes.
What else can Age-Related Fertility Decline be?
When it comes to understanding age-related infertility, many other underlying causes should also be considered. Even though there are countless reasons a person can become infertile, the main three factors include issues with ovulation, issues with the fallopian tubes, and issues related to male fertility.
Additional factors such as environmental influences, problems with sexual function, genetic abnormalities, premature drop in ovarian function, or unexplained infertility can also contribute towards a decline in fertility as one gets older.
What to expect with Age-Related Fertility Decline
Although there’s no cure for the decline in fertility that comes with age, quick evaluation and referral to a fertility specialist can give patients several treatment options. This is crucial, as a diagnosis of infertility can have emotional impacts. So, the best thing a women’s health doctor can do for older patients wanting to have a baby is to quickly evaluate them and refer them to a specialist.
However, it’s also important to note that fertility treatments can be very expensive and insurance doesn’t always cover the cost. Hence, by discussing family planning and fertility preservation options during routine check-ups when women are younger, there might be an opportunity to delay having children without worrying too much about age-related fertility decline. These decisions can be made together, depending on the individual’s situation.
Possible Complications When Diagnosed with Age-Related Fertility Decline
There are several potential challenges and complications associated with fertility declining with age. One issue could be an inability to conceive. Using assisted reproductive technology can be expensive and has lower success rates, particularly for older women. Additionally, women giving birth at the age of 34 or older face higher risks. These include increased rates of miscarriage, preterm birth, and birth defects, and these risks are amplified after the age of 40. Even if pregnancy is achieved, there are elevated risks of conditions such as high blood pressure during pregnancy, preeclampsia, and gestational diabetes.
Potential complications:
- Inability to conceive
- High costs and low success rates of assisted reproductive technology
- Increased rates of miscarriage, preterm birth, and birth defects for women giving birth at 34 or older, particularly after 40
- Higher risks of high blood pressure during pregnancy, preeclampsia, and gestational diabetes
Preventing Age-Related Fertility Decline
OBGYN doctors play a crucial role in providing advice to patients during their regular check-ups. These doctors discuss different ways to optimize fertility, such as maintaining a healthy weight, adopting a healthy lifestyle, which includes quitting smoking and reducing alcohol consumption. These discussions are equally important for all patients, whether or not they are actively trying to get pregnant. Changes in societal norms today have led to women having fewer children and starting families later in life than previous generations.
However, once diagnosed with infertility, treatment options may not be accessible due to high costs and inadequate insurance coverage. Furthermore, many women have misconceptions about fertility decline with age. They wrongly believe they can control their fertility, as if it remains constant. Even medical professionals, surprisingly, may lack sufficient resources and knowledge in this area. There’s a strong inclination to overestimate the success rates of fertility treatments such as IVF, particularly for older women.
Unfortunately, there aren’t many studies or measures tackling fertility decline with age. Therefore, fertility education should encompass the age-related decline in fertility in both men and women. As women get older, they might need to rely on donated eggs or sperm for fertility treatments. Hence, it’s crucial for doctors to provide fertility advice to all patients considering parenthood someday.
