Introduction
Age has an effect on fertility. Following puberty, both sexes become reproductive in their twenties. Ovulation and menstruation appear to signal the beginning of a woman’s reproductive years in girls. After menopause, it is widely accepted that women are no longer able to conceive. As women become older, their reproductive capacity diminishes, and by the time they reach the age of menopause, their fertility will have all but vanished.
As many women wait until their 30s to start babies, age-related infertility is becoming more widespread in today’s culture. When it comes to reproduction, greater health in old age is not enough to compensate for the natural drop in fertility that occurs as women become older. As a woman ages, her fertility drops owing to the typical age-related reduction in the amount of eggs remaining in her ovaries. This is vital to understand. Most women don’t expect this drop to occur as quickly as it will.
Menstruation and Ovulation
• Because they ovulate on a monthly basis, women throughout their reproductive years’ experience regular monthly menstrual cycles. Follicles, the fluid-filled spheres in which eggs develop, are known as “oocytes.” A hormone released in the pituitary gland, which is located in the brain, promotes a group of follicles to develop more rapidly on both ovaries at the beginning of each menstrual cycle.
• Follicle-stimulating hormone is the pituitary hormone that stimulates the ovaries (FSH). Follicles normally mature and release an egg (ovulate) just once; the rest progressively cease developing and disintegrate over time. If the egg is fertilised and implanted in the uterine lining, the consequence is pregnancy (endometrium).
• Menstruation sheds the endometrium if a pregnancy is not successful, and the cycle repeats itself. Although irregular ovulation and irregular menstrual cycles are common among females in their adolescent years, by the age of 16 they should have established normal ovulation and regular menstruation.
• Until her late 30s or early 40s, a woman’s cycle will be consistent, lasting 26 to 35 days, but then she may discover that her periods are getting shorter. Eventually, she’ll start skipping her periods because to ovulation issues. The frequency of periods eventually decreases until they are nonexistent. A woman is said to be in menopause if she has gone a full year without having a menstrual cycle.
• Due to typical ageing changes in the ovaries, a woman’s fertility falls as she gets older. A woman’s ovaries contain all the egg-producing follicles she will ever have, unlike males, who continue to generate sperm throughout their lives.
• One million follicles are present at birth. When children reach adolescence, that number drops to around 300,000. Only around 300 of a woman’s surviving follicles at puberty will ovulate during her reproductive years. Most follicles are depleted not by ovulation but rather by atresia, a slow and steady loss.
• If you have regular menstrual cycles, utilise birth control, or are undergoing infertility treatment, atresia might still develop. There is some evidence that women who smoke go through menopause around a year early.
The Aging Female’s Fertility
• When a woman is in her 20s, she is at her most fertile. After the age of 35, fertility begins to wane more noticeably. Each time a 30-year-old woman attempts to get pregnant, she has a 20% chance of conceiving. There will be 20 successful pregnancies out of every 100 30-year-old women who try to get pregnant in a single cycle. Only 5 out of 100 women are predicted to conceive each month beyond the age of 40, therefore the chances of a woman having a baby are slim.
• Menopause is the last time a woman is fertile. Women typically reach menopause around the age of 51, but most are unable to conceive by the time they reach their mid-40s.
• These percentages apply to both naturally occurring conceptions and conceptions resulting from in vitro fertilisation and other forms of reproductive treatment (IVF). In spite of the media’s portrayal of infertility treatments like IVF as having high success rates, a woman’s age has a significant impact on the likelihood of a successful pregnancy.
• Female fertility declines as a result of a decrease in both the quality and number of eggs.
Quality of the Eggs
• The quality of a woman’s eggs declines as the quantity of surviving eggs diminishes, making her less likely to get pregnant and more likely to miscarry. As she nears her 30s, these changes become more pronounced. As a result, the best indicator of the quality of an egg is the woman’s age.
• Aneuploidy, a genetic abnormality, is a significant alteration in egg quality (too many or too few chromosomes in the egg). Normal eggs contain 23 chromosomes upon fertilisation, and a sperm with 23 chromosomes fertilises the egg to produce an embryo with 46 chromosomes.
• More and more of a woman’s eggs contain an abnormally high or low number of chromosomes as she ages. In the event of fertilisation, the embryo will also have an abnormal number or an abnormal number of chromosomes. Most people have heard about Down syndrome, a genetic disease caused by an extra copy of chromosome 21 in an embryo.
• In most cases, embryos with an abnormally high or low number of chromosomes do not lead to pregnancy or miscarriage at all. This explains why older women have a reduced likelihood of getting pregnant and a higher chance of miscarrying.
Counting the number of eggs
• “Loss of ovarian reserve” refers to the ovaries having fewer egg-producing follicles. Before they become infertile or cease having regular cycles, women start losing their ovarian reserve. Women are born with all the follicles they will ever have, therefore the waiting follicular pool is steadily depleted.
• The follicles become less responsive to FSH stimulation as ovarian reserve decreases, requiring greater stimulation to develop and ovulate an egg. It’s possible that at initially, your periods will come closer together, resulting in 21 to 25-day cycles. Over time, the follicles lose their ability to react properly, resulting in erratic, protracted cycles.
• The loss of eggs and the decline in the quality of the remaining eggs are the most common causes of a reduced ovarian reserve. Smoking, a family history of early menopause, and previous ovarian surgery can all lower a woman’s ovarian reserve in her twenties. Even if there are no established risk factors, young women may have a reduced ovarian reserve.
• Although ovarian reserve may be measured using medical tests, none of them has been shown to accurately predict the likelihood of becoming pregnant. A woman’s fertility can’t be determined by these tests, but they can tell if her ovaries have begun to alter with age.
• Getting pregnant is more difficult for women with low ovarian reserve than it is for women in the same age group who have normal ovarian reserve. There is no one test or combination of tests that is 100% correct. Day 2, 3, or 4 of the menstrual cycle is used to collect blood samples for the day-3 FSH, antimüllerian hormone, and oestrogen tests.
• Ovarian reserve is poor when FSH or oestrogen levels are elevated. It is important to note, however, that FSH levels on day 3 may be normal in women with a reduced ovarian reserve. Antral follicle count (AFC) and the clomiphene citrate challenge test (CCCT) are two further assays of ovarian reserve that may be employed.
FAQ
How does age affect the fertility of a woman?
A decline in fertility occurs after the age of 35 due to a decrease in both egg production as well as egg quality. Every month from the time you reach adolescence until you reach menopause, an egg travels from your ovaries to your uterus. You get pregnant once the egg and sperm unite in the womb.
Is there a correlation between age and fertility?
Men and women’s fertility declines as they become older. A woman’s age is the most important element in her ability to conceive and give birth to a healthy kid. In her early 30s, a woman’s fertility begins to decline, and becomes more pronounced beyond the age of 35. Pregnancy problems are more likely to occur in older women.
Why is it harder to get pregnant as you age?
Having fewer eggs, less frequent ovulation, and worse egg quality are all factors that contribute to a normal age-related reduction in fertility. It’s possible that you’ll release fewer eggs each cycle as you become older. In your 30s and 40s, the quality of your eggs may deteriorate.
What is the oldest age a woman can get pregnant naturally?
When it comes to fertility, there is no maximum age at which a woman can conceive naturally. Between the ages of 5 and 10 years before menopause, most women cannot get pregnant. All of your future eggs are in your uterus when you are born.