Fertility changes with age.
Both males and females become fertile in their teens following puberty.
For girls, the beginning of their reproductive years is marked by the onset of ovulation and menstruation. It is commonly understood that after menopause women are no longer able to become pregnant. Generally, reproductive potential decreases as women get older, and fertility can be expected to end 5 to 10 years before menopause.
In today’s society, age-related infertility is becoming more common because, for a variety of reasons, many women wait until their 30s to begin their families. Even though women today are healthier and taking better care of themselves than ever before, improved health in later life does not offset the natural age-related decline in fertility. It is important to understand that fertility declines as a woman ages due to the normal age-related decrease in the number of eggs that remain in her ovaries. This decline may take place much sooner than most women expect.
It’s a biological fact that as women and men age, their potential to have children decreases, although the exact time when this starts to happen can vary among individuals.
We all know someone who had a healthy baby in their late 30s or early 40s. But of all people who try for a baby at a later age, many will not have the baby they hoped to have.
Across a population, women younger than 35 and men younger than 40 have a better chance of having a child than people who are older.
AGE AND SPERM
Men younger than 40 have a better chance of fathering a child than those older than 40. The quality of the sperm men produce seems to decline as they get older.
Most men make millions of new sperm every day, but men older than 40 have fewer healthy sperm than younger men. The amount of semen and sperm motility decrease continually between ages of 20 and 80.