An estimated 12% of couples in the U.S. struggle with infertility. Learn the basics here – and the most common contributing factors in women.
What is infertility?
Considered a disease of the reproductive system, infertility is defined as the inability to achieve pregnancy after 12 months or more of regular, unprotected sex (or after 6 months if the woman is older than 35).
To best understand infertility, it can be helpful to begin by outlining what is necessary for fertility. In order to conceive, three things are required:
– Sperm. A man must have healthy sperm production and have no functional problems with the delivery of sperm.
– Ovulation. A woman’s ovaries must be able to release an egg.
– Open fallopian tube. A woman must have one fallopian tube open and able to capture the egg and allow sperm to travel from the uterus to the tube, where fertilization occurs.
Infertility is often viewed as a “woman’s problem,” despite the fact that it is equally common in men. According to the U.S. Department of Health and Human Services’ Office on Women’s Health, about one third of infertility cases are caused by a female factor, another one third are caused by a male factor, and the remaining cases are due to a combination of male and female factors or by unknown problems.
What causes infertility in women?
In women, infertility is often influenced by normal age-related changes in the ovaries. A woman is born with all of the eggs she will ever have, and her body will typically use (or ovulate) its best eggs earlier in life. As she ages, both egg count and egg quality decrease. Those remaining are more likely to have hard shells that keep sperm from penetrating, or genetic defects that cause abnormalities in the fertilized eggs, some of which cause miscarriage. Infertility in women can also be tied to problems with ovulation – without ovulation, there are no eggs released to be fertilized. Problems with ovulation may be due to polycystic ovary syndrome (PCOS), a hormonal disorder, or primary ovarian insufficiency (POI), when a woman’s ovaries have premature aging (meaning they stop producing normal amounts of estrogen and releasing eggs regularly) before she reaches age 40. Other risk factors for infertility in women include obesity, blocked fallopian tubes (which can be due to pelvic inflammatory disease or endometriosis), and physical problems with the uterus including fibroids, which are benign muscle tumors, and scar tissue.