Infertility

Definition

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

Alternative Names

Causes

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

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

Causes of infertility include a wide range of physical and emotional factors. About 30 - 40% of all infertility is due to a "male" factor such as:

• Decreased sperm count
• Environmental pollutants
• Hormone deficiency
• Impotence
• Retrograde ejaculation
• Scarring from sexually transmitted disease

Some factors that affect sperm count are:

• Heavy marijuana use
• Use of prescription drugs such as cimetidine, spironolactone, and nitrofurantoin

"Female" factor causes include:

• Abnormal egg transport from the cervix through the fallopian tubes (causes 40 - 50% of infertility in couples)
• Hormone imbalance
• Ovarian cysts
• Pelvic infection
• Poor nutrition
• Problem with ovulation
• Scarring from sexually transmitted disease or endometriosis
• Tumor

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

About 10 - 20% of couples will be unable to conceive after 1 year of trying to become pregnant. It is important that you try to get pregnant for at least 1 year.

The chances for a pregnancy in healthy couples who are both under the age of 30 and having sex regularly is only 25 - 30% per month. A woman's peak fertility occurs in her early 20s. As a woman ages beyond 35 (and especially after age 40), the likelihood of getting pregnant drops to less than 10% per month.

In addition to age-related factors, other infertility risks include:

• Anovulatory menstrual cycles
• Autoimmune disorders, such as antiphospholipid syndrome (APS)
• Clotting disorders (thrombophilia)
• Defects of the uterus (myomas) or blockage of the cervix
• Eating disorders (women)
• Endometriosis
• Exposure to the drug diethylstilbestrol (DES)
• History of orchitis or epididymitis in men
• Long-term (chronic) disease such as diabetes
• Pelvic inflammatory disease (PID)
• Many sexual partners
• Mumps (men)
• Sexually transmitted diseases
• Varicocele (men)

References

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.