It is not uncommon to have trouble becoming pregnant or to experience infertility.

Infertility is defined as not being able to become pregnant, despite trying for one year, in women under age 35, or after six months in women 35 and over.

Pregnancy is the result of a chain of events. A woman must release an egg from one of her ovaries (ovulation). The egg must travel through a fallopian tube toward her uterus. A man's sperm must join with (fertilize) the egg along the way. The fertilized egg must then become attached to the inside of the uterus. While this may seem simple, in fact many things can happen to prevent pregnancy.

Reasons for Infertility

Age

There are many different reasons why a couple might have infertility. One is age-related. Women today are often delaying having children until later in life, when they are in their 30s and 40s.

A couple of factors add to this trend.

Birth control is easy to obtain and use, more women are in the work force, women are marrying at an older age, the divorce rate remains high, and married couples are delaying pregnancy until they are more financially secure. But the older you are, the harder it is to become pregnant. Women generally have some decrease in fertility starting in their early 30s. And while many women in their 30s and 40s have no problems getting pregnant, fertility especially declines after age 35.

As a woman ages, there are normal changes that occur in her ovaries and eggs. All women are born with over a million eggs in their ovaries (all the eggs that they will ever have), but only have about 300,000 left by puberty.

Of these, only about 300 eggs will be ovulated during the reproductive years. Even though menstrual cycles continue to be regular in a woman's 30s and 40s, the eggs that ovulate each month are of poorer quality than those from her 20s. It is harder to get pregnant when the eggs are poorer in quality.

Ovarian reserve is the number and quality of eggs in your ovaries and how well the ovarian follicles respond to hormones in your body. As you approach menopause, your ovaries don't respond as well to your hormones, and in time they may not release an egg each month. A reduced ovarian reserve is natural as a woman ages, but young women might have reduced ovarian reserves due to smoking, a prior surgery on their ovaries, or a family history of early menopause.

Also, as a woman and her eggs age, if she becomes pregnant, there is an increase incidence of pregnancy complications including genetic problems such as having a baby with Down Syndrome. Embryos formed from eggs in older women also are less likely to fully develop, a main reason for miscarriage (early pregnancy loss).

Health Problems

Couples also can have fertility problems because of health problems, in either the woman or the man. Common problems with a woman's reproductive organs, like uterine fibroids, endometriosis, and pelvic inflammatory disease can worsen with age and also affect fertility. These conditions might cause the fallopian tubes to be blocked, so the egg can't travel through the tubes into the uterus.

Some people also have diseases or conditions that affect their hormone levels, which can cause infertility in women and impotence and infertility in men. Polycystic Ovarian Syndrome (PCOS) is one such hormonal condition that affects many women, and is the most common cause of anovulation, or when a woman rarely or never ovulates.

Another hormonal condition that is a common cause of infertility is when a woman has a luteal phase defect (LPD). A luteal phase is the time in the menstrual cycle between ovulation and the start of the next menstrual period. LPD is a failure of the uterine lining to be fully prepared for a fertilized egg to implant there.

This happens either because a woman's body is not producing enough progesterone, or the uterine lining isn't responding to progesterone levels at some point in the menstrual cycle. Since pregnancy depends on a fertilized egg implanting in the uterine lining, LPD can interfere with a woman getting pregnant and with carrying a pregnancy successfully.

Certain lifestyle choices also can have a negative effect on a woman's fertility, such as smoking, alcohol use, weighing much more or much less than an ideal body weight, a lot of strenuous exercise, and having an eating disorder.

Unlike women, some men remain fertile into their 60s and 70s. But as men age, they might begin to have problems with the shape and movement of their sperm, and have a slightly higher risk of sperm gene defects. They also might produce no sperm, or too few sperm.

Lifestyle choices also can affect the number and quality of a man's sperm. Alcohol and drugs can temporarily reduce sperm quality. And researchers are looking at whether environmental toxins, such as pesticides and lead, also may be to blame for some cases of infertility.

Men also can have health problems that affect their sexual and reproductive function. These can include sexually transmitted diseases (STDs), diabetes, surgery on the prostate gland, or a severe testicle injury or problem.

If you or your partner has a problem with sexual function or libido, don't delay seeing your doctor for help.

Treating Infertility

You should talk to your doctor about your fertility if you:

  • are under age 35 and, after a year of frequent sex without birth control, you are having problems getting pregnant, or
  • are age 35 or over and, after six months of frequent sex without birth control, you are having problems getting pregnant, or
  • believe you or your partner might have fertility problems in the future (even before you begin trying to get pregnant).

Your doctor can refer you to a fertility specialist, a doctor who focuses in treating infertility. This doctor can recommend treatments such as drugs, surgery, or assisted reproductive technology. Don't delay seeing your doctor because age also affects the success rates of these treatments.