Infertility affects men and women of all ages, however, age itself is an important contributing factor. Both males and females become fertile during their teens following puberty. While fertility decreases over the years, the speed and decline vary for men vs. women.
Understanding how age affects your fertility is a helpful part of your family planning and knowing when it is time to see a fertility specialist.
Women’s fertility decreases more quickly over time than men because women have a limited quantity of eggs that will eventually run out. Age also affects the quality of eggs over time which increases the chance of miscarriage and birth defects.
Egg Quantity
The amount of eggs a woman has is called Ovarian Reserve. As women age, that reserve decreases each month as unfertilized eggs are released through the menstrual cycle. Ovarian reserve is most often affected by age and natural egg loss, but can be reduced sooner due to lifestyle factors such as smoking and excessive alcohol use.
Egg Quality
As a woman ages, a larger portion of ovulated eggs contain less than or more than the normal number of 23 chromosomes. This is called Aneuploidy and results in lower pregnancy rates, higher miscarriage rates and higher rates of chromosomal diseases, such as Down Syndrome.
The most fertile window for a woman is during her 20s with a gradual decline during her 30s and the fertile window closing before menopause. Even though the average age of menopause is around age 50, most women are unable to have a successful pregnancy in their mid-40s. This applies to natural conception and conception through infertility treatments. Certain fertility conditions, such as endometriosis and conditions of the uterus, such as uterine fibroids and polyps, tend to be more common or more severe as women get older.
Research shows that men’s sperm quality decreases over time as well, resulting in decreased fertility, increased risk of miscarriage, and a slight increase in certain chronic illnesses in offspring. While sperm quality does decrease over time, it typically does not become a problem for men until their 60s. As men age, they experience fertility changes and changes in their sexual function including softer and smaller testes, a decline in sperm shape (morphology) and movement (motility), development of medical conditions, development of erectile dysfunction, or decreased libido which could be associated with low testosterone level.
Over the years, the average age of men and women at their first birth has increased by 5 years, and has increased fertility challenges. Though the reasons for delaying conception may vary, understanding your life goals in relation to how age affects your fertility will help you with family planning. Advances in reproduction technologies allow fertility preservation for couples who are wanting to delay their efforts to conceive. For more information, click below.