Causes
There are hundreds of medical problems that can cause infertility in both
men and women.
Causes of infertility in men include:
- hormone disturbance
- smoking
- overheating of the testicles caused by exercise, hot water, tight
clothing, excessive sitting (truck drivers) and other conditions and
situations
- cancer drugs and radiation therapy
- mumps after puberty
- sexually transmitted diseases
- anatomical abnormalities of the genitals such as undescended testicles
- use of some medications, such as some antihypertensives, some antidepressants,
and male hormones
- genital injury
- prostate surgery
- varicose veins in the testicles
- excessive alcohol
- intercourse problems such as premature withdrawal or poor timing with
their partner's menstrual cycle
- spinal cord injury
- genetic abnormalities
- urinary tract infection
- cystic fibrosis
Some men are more prone than others to infertility problems. These factors
contribute to risk:
- diabetes
- poor nutrition
- smoking (lowers sperm count and reduces erections)
- hot baths
- being very overweight or underweight
Sperm counts are going down in industrialized countries due to unknown
environmental factors.
Types of male infertility include:
- azoospermia - no sperm in the ejaculate
- oligospermia - low concentrations of sperm in the ejaculate
- asthenospermia - sperm are present but can't swim normally
- teratospermia - high proportion of abnormally shaped sperm
- retrograde ejaculation - the tube through which sperm normally
travel is blocked and sperm may end up in the bladder
Causes of infertility in women include:
- age
- chlamydia and other sexually transmitted diseases
- damaged ovaries
- blocked fallopian tubes
- hypothyroidism (a thyroid disorder)
- polycystic ovary syndrome (a collection of symptoms that can affect a woman's
reproductive health and heart health)
- scarring in the uterus
- fibroids (benign smooth muscle tumors of the uterus)
- congenital diseases like cystic fibrosis
- over-exercise (only if it leads to losing menstrual periods)
- anorexia or bulimia
- frequent changes in weight
- damage to the cervix (often from previous births)
Advancing age eventually makes all women infertile. Women in their late
30s and early 40s naturally have a harder time conceiving, even with treatment.
Infertility may seem more common these days because people marry and consider
parenthood later in life. Even though a woman may be in excellent physical shape
and feel great in her late 30s and early 40s, aging has still taken place inside
her ovaries.
Women may be concerned that having used birth control pills and injections
could possibly make them less fertile after they have stopped using them. This
is not true. However, some women may notice that it takes a short while for
their fertility to return after they stop taking birth control pills or injections.
Talk to your doctor or pharmacist about whether this may occur for your method
of birth control and if so, how long this time may be.
Upon examination, between 40% to 50% of infertile women of reproductive
age are found to have past or present endometriosis.
Another cause, which may also cause low sperm counts in men, is hyperprolactinemia.
This is an excess of the hormone prolactin, which normally stimulates
breast milk production in women. High prolactin levels can interfere with ovulation
and menstruation. Stress, marijuana, and hypothyroidism are among the factors
believed to contribute to high prolactin levels.
Some women suffer repeated miscarriages. These miscarriages can further damage
the reproductive system. They're often due to immune problems or a uterus that
is too small or is slightly misshapen. Sometimes the cause is scars or other
unwanted tissue in the fallopian tubes or the uterus.
In a few cases, perfectly healthy couples can't conceive because the tissue
type of the mucous lining in the woman's cervix is deadly to the man's sperm.
The couple may be "incompatible" in reproductive terms. Occasionally,
the man's sperm is unable to penetrate the woman's egg.