Infertility is the inability to become pregnant after 12 months of unprotected intercourse.

Primary infertility is the term used to describe a couple that has never been able to conceive a pregnancy, after at least 1 year of unprotected intercourse.

Secondary infertility describes couples who have previously been pregnant at least once, but have not been able to achieve another pregnancy.

Causes of infertility include a wide range of physical as well as emotional factors. Approximately 30 - 40% of all infertility is due to a "male" factor such as retrograde ejaculation, impotence, hormone deficiency, environmental pollutants, scarring from sexually transmitted disease, or decreased sperm count. Some factors affecting sperm count are heavy marijuana use or use of prescription drugs such as cimetidine, spironolactone, and nitrofurantoin.

A "female" factor -- scarring from sexually transmitted disease or endometriosis, ovulation dysfunction, poor nutrition, hormone imbalance, ovarian cysts, pelvic infection, tumor, or transport system abnormality from the cervix through the fallopian tubes -- is responsible for 40 - 50% of infertility in couples.

The remaining 10 -30% of infertility cases may be caused by contributing factors from both partners, or no cause can be identified.

It is estimated that 10 - 20% of couples will be unable to conceive after 1 year of trying to become pregnant. It is important that pregnancy be attempted for at least 1 year. The chances for pregnancy occurring in healthy couples who are both under the age of 30 and having intercourse regularly is only 25 - 30% per month. A woman's peak fertility occurs in her early 20s. As a woman ages beyond 35 (and particularly after age 40), the likelihood of getting pregnant drops to less than 10% per month.

In addition to age-related factors, increased risk for infertility is associated with the following:

• Multiple sexual partners (increases risk for sexually transmitted diseases)
• Sexually transmitted diseases
• History of PID (pelvic inflammatory disease)
• History of orchitis or epididymitis in men
• Mumps (men)
• Varicocele (men)
• A past medical history that includes DES exposure (men or women)
• Eating disorders (women)
• Anovulatory menstrual cycles
• Endometriosis
• Defects of the uterus (myomas) or cervical obstruction
• Long-term (chronic) disease such as diabetes

• Inability to become pregnant.
• A range of emotional reactions by either or both members of the couple. In general, such reactions are greater among childless couples. Having at least one child tends to soften these painful emotions.

A complete history and physical examination of both partners is essential.

Tests may include:

• Semen analysis -- the specimen is collected after 2 to 3 days of complete abstinence to determine volume and viscosity of semen and sperm count, motility, swimming speed, and shape.
• Measuring basal body temperature -- taking the woman's temperature each morning before arising in an effort to note the 0.4 to 1.0 degree Fahrenheit temperature increase associated with ovulation.
• Monitoring cervical mucus changes throughout the menstrual cycle to note the wet, stretchy, and slippery mucus associated with the ovulatory phase.
• Postcoital testing (PCT) to evaluate sperm-cervical mucus interaction through analysis of cervical mucus collected 2 to 8 hours after the couple has intercourse.
• Measuring serum progesterone (a blood test).
• Biopsying the woman's uterine lining (endometrium).
• Biopsying the man's testicles (rarely done).
• Measuring the amount of luteinizing hormone in urine with home-use kits to predict ovulation and assist with timing of intercourse.
• Progestin challenge when the woman has sporadic or absent ovulation.
• Serum hormonal levels (blood tests) for either or both partners.
• Hysterosalpingography (HSG) -- an x-ray procedure done with contrast dye that looks at the route of sperm from the cervix through the uterus and fallopian tubes.
• Laparoscopy to allow direct visualization of the pelvic cavity.
• Pelvic exam for the woman to determine if there are cysts.

Treatment depends on the cause of infertility. It may involve:

• Simple education and counseling
• Medicines to treat infections or promote ovulation
• Highly sophisticated medical procedures such as in vitro fertilization

It is important for the couple to recognize and discuss the emotional impact that infertility has on them as individuals and together and to seek medical advice from their health care provider.

Many organizations provide informal support and referrals for professional counseling. See infertility - support group.

A cause can be determined for about 85- 90% of infertile couples.

Appropriate therapy (not including advanced techniques such as in vitro fertilization) allows pregnancy to occur in 50 - 60% of previously infertile couples.

Without any treatment intervention, 15 -  20% of couples previously diagnosed as infertile will eventually become pregnant.

Although infertility itself does not cause physical illness, the psychological impact of infertility upon individuals or couples affected by it may be severe. Couples may encounter marital problems, as well as individual depression and anxiety.

Call for an appointment with your health care provider if you are unable to achieve a desired pregnancy.

Because infertility is frequently caused by sexually transmitted diseases, practicing safer sex behaviors may minimize the risk of future infertility. Gonorrhea and chlamydia are the two most frequent causes of STD-related infertility.

STDs are often asymptomatic at first, until PID or salpingitis develops. These inflammatory processes cause scarring of the fallopian tubes and decreased fertility, absolute infertility, or an increased incidence of ectopic pregnancy.

Mumps immunization has been well demonstrated to prevent mumps and its male complication, orchitis. Immunization prevents mumps-related sterility.

Some forms of birth control, such as the intrauterine device (IUD), carry a higher risk for future infertility. However, IUDs are not recommended for women who have not previously had a child.

Women selecting the IUD must be willing to accept the very slight risk of infertility associated with its use. Careful consideration of this risk, weighed with the potential benefits, should be reviewed and discussed with both partners and the health care provider.

Early diagnosis and treatment of endometriosis may decrease the risk of infertility.

Speroff L, Fitz M. Clinical Gynecologic Endocrinology and Infertility. 7th ed. Lippincott Williams & Wilkins; 2004.

Stenchever A. Comprehensive Gynecology. 4th ed. St. Louis, Mo: Mosby; 2001:1204-1206.