Age and Fertility – Overview
Fertile age is the period during which it is possible to conceive, carry and give birth to a child.
Fertility changes with age. Both women and men become fertile in adolescence after puberty.
For girls, their early reproductive development is characterized by the onset of ovulation and menstruation and for boys, it’s the sperm arched.
How does aging affect fertility for women and men?
The fertility period not only starts but ends differently for men and women. We will cover both since it’s the combination of both parents’ ages that determines the likelihood of pregnancy.
Age of Fertility in Women
The prime years of reproductive age for women start at around 20 years old. Fertility gradually decreases by the age of 30 and steeply decreases after the age of 35.
Although women today are healthier and are looking after themselves better than ever before, improved health later in life can’t compensate for the naturally occurring decline in fertility due to age.
This decline may occur much earlier than most women expect, although this depends on the individual.
Every month a healthy, fertile 30-year-old woman tries to get pregnant, there is approximately a 60% chance of it happening.
From 45 years old and above, a woman’s chance of getting pregnant is less than 5% per cycle, which means that only 5 women out of 100 can be expected to succeed each month.
The average age of menopause is 51.
After menopause, women are no longer fertile. In general, when a woman begins to age, her reproductive potential decreases and may end as early as 5-10 years before menopause.
In modern society, age is becoming a more and more common cause of infertility because, for various reasons, many women wait until the age of 30 or later to start their own families.
These percentages are true for natural conception and for conception using the in vitro fertilization (IVF) method.
Although the media can often convince women and their partners that with IVF they will be able to conceive a child, you need to know that a woman’s age greatly influences the success rates of infertility treatment.
It is important to note that maternal age is also a big factor for developing various chromosomal anomalies, for example, the risk of down’s syndrome is 1 in 1667 for mothers aged 20 and 1 in 250 for those aged 35.
Screening tests and genetic tests are often recommended for older couples trying to conceive.
Reason for fertility decline with age
Why is it so difficult for a woman to get pregnant as she gets older? Some physiological causes explain fertility decline with age
- Eggs’ quality
As women age, they are less likely to become pregnant and more likely to miscarry, as the quality of the eggs deteriorates and the number of remaining eggs decreases. Such changes are most pronounced in women closer to forty years old. For this reason, a woman’s age is the most accurate test of egg quality.
- Loss of “ovarian reserve”
A decrease in the number of follicles containing eggs in the ovaries is called “loss of ovarian reserves.” Women begin to lose ovarian reserves before they become infertile, even before they stop menstruating regularly.
Since women are born with the same set of follicles that they will have throughout their lives, the number of follicles is diminishing gradually with time.
As ovarian reserves decrease, follicles become less and less susceptible to IVF and require more and more stimulation of the egg to mature and ovulate.
- Reproductive tract anomalies
Older age is one of the risk factors for developing diseases like uterine fibroids, and endometriosis, which can be causes of infertility.
Fibroids are most common in women aged 30-40.
Age of fertility and men
In contrast to women, in men, the rate of decline in fertility occurs much later. It is true that with time sperm quality deteriorates, but in general, it does not become a problem until the age of 60.
Men, unlike women, do not experience such sudden or noticeable changes in fertility and sexual activity. These changes become more noticeable only with aging.
Despite these changes, there is no maximum age at which a person can not conceive. As a man ages, his testosterone levels decline gradually, stabilizing around the age of 60.
Most men notice changes in their sex life around the age of 60-65. The decrease in testosterone is the main reason for the changes that occur in men in their sex life.
Causes of fertility decline in men
- Testes tend to become smaller and softer,
- Sperm structure changes
- Sperm motility tends to slow down.
- Aging men often develop illnesses that can adversely affect their reproductive and sexual function for which they should pay a visit to a urologist if they’re planning to conceive.
To sum up
Fertility naturally declines as you age. Even though the time of decline in fertility and the onset of menopause varies significantly in women, this period occurs in the life of every woman.
As a rule, fertility begins to decline around the age of 30 and drops noticeably at the age of 35.
Women who decide to postpone pregnancy until the age of 35 and beyond should be realistic about the chances of success, be aware of the possibilities of conception, and, if necessary, use fertility therapy.
After reviewing all the options and realizing their needs and goals, the woman and her partner will be able to make the best decision.
According to NCBI: “Public awareness of this fact is important as the age-related decline in fecundity leaves the clinician and the couple with limited treatment options.
From a pure fertility aspect, delay in childbearing should be avoided.”
Men’s fertility declines with age too, but not as predictably and it mostly happens at much later ages than for women.