Reproductive Aged Population Affected: 9%
About 5.3 million people in the U.S. suffer from infertility, affecting men and women equally. The average couple attempting conception has about a 20% chance of conceiving per menstrual cycle. This means that it is unlikely that a pregnancy will result after the first or even second month of trying. However, 95% of couples do conceive within 13 months. The minority who do not become pregnant after a year's time still have a good chance — only about a quarter of these will never conceive. Indeed, the average "infertile" couple will experience a pregnancy, whether or not they seek out infertility testing and treatment.
|Chances of Pregnancy by Day of Intercourse
day zero is ovulation
Factors Affecting Reproductive Performance
Why it May be Difficult to Get Pregnant
Age of the Woman: Beginning her late thirties a woman may take longer to conceive, due in part to decreasing sexual activity and the cumulative effects of medical and gynecological problems.
Both of the line graphs are for women with normal reproductive function, after having unprotected intercourse for one year.
Source: Management of the Infertile Woman by Helen A. Carcio and The Fertility Sourcebook by M. Sara Rosenthal.
Age of the Man: Although sperm remain potent even in old age, older men are more likely to experience problems with sexual function and also a decreased frequency of sexual activity.
Frequency of Intercourse: Many couples simply don't have sex often enough to conceive.
Timing of Intercourse: Intercourse just before ovulation is the key to maximizing the chances of pregnancy. Although the egg will live for only 12 hours, sperm live for about 72 hours in the female genital tract. Waiting sperm can allow for immediate fertilization upon ovulation. See above table for chances of pregnancy by day of intercourse.
Sexual Position: The best position for intercourse is when the woman is lying on her back, with hips elevated by a pillow. She should remain in this position for twenty minutes following intercourse to allow more time for sperm to migrate into the uterus and fallopian tubes
Lubricants: Some lubricants, like K-Y Jelly, may have spermicidal properties. And some couples may mistakenly use spermicides as sexual lubricants.
Douching: Though not very effective as a form of birth control, douching may kill enough sperm in couples with marginal fertility to prevent conception.
Multiple Sexual Partners: The more sexual partners a woman has, the more likely is her risk for sexually transmitted disease, pelvic inflammatory disease, and other conditions which can damage the reproductive structures. Also multiple sexual partners is thought to be a factor in women who develop antibodies to sperm.
Sexually Transmitted Disease: STDs are the leading cause of infertility. Chlamydia and gonorrhea cause infertility in both men and women. HPV can damage the cervix. Other STDs can also cause damage. [More on Sexually Transmitted Disease and PID.]
Parasites and Other Diseases: Toxoplasmosis, malaria, leprosy, and tuberculosis, though uncommon in the United States, can be a cause of infertility. Mumps can cause infertility in a small fraction of men.
Previous Pregnancy: Problems with delivery or abortion can result in infection. Laceration, uterine injury, hemorrhaging which requires hysterectomy, as well as emotional trauma from a difficult experience can all impair future fertility. Stress from raising small children or post-abortion stress can also contribute to infertility.
Sickle Cell Disease: Sickle cell disease can cause impotence in men, and miscarriage in women.
Lifestyle and Environmental Factors
Nutrition: A drop below 10-15% of a woman's body weight can interfere with fertility. A woman should have at least 22% body fat to maintain regular ovulation. Eating disorders can be a major cause of infertility.
Toxins: Lead, toxic fumes, and pesticides are thought to be contributing factors for infertility in men and women.
Smoking & Alcohol: Both of these are associated with poor sperm quality in men and lower conception rates in women.
Medications: Many drugs can cause impaired fertility in both men and women, including antidepressants, tranquilizers, and narcotics. Anti-cancer drugs can cause ovarian and testicular failure temporarily or permanently. Additionally, many drugs can cause miscarriage or fetal defect once pregnancy has begun. Avoiding all medications while attempting to conceive and during pregnancy is best whenever possible.
Surgery: Any surgery involving the reproductive structures can lead to infertility. Talk to your doctor in detail about the implications of the surgery on future reproductive functioning beforehand. Of course, surgical sterilization will usually cause infertility and should be considered permanent.
Radiation: Radiation exposure, especially the levels associated with cancer treatment, can cause infertility in both women and men. High doses can cause miscarriage or fetal defect in pregnant women.
Athletics: Some highly trained female athletes may experience reversible lack of menstruation and ovulation. There's no evidence that endurance training leads to male infertility.
Heat Exposure: Men who take frequent hot showers or whirlpool treatments, and men whose jobs involves high degrees of heat for long periods of time may subject the scrotum to temperatures high enough to temporarily reduce sperm production.
Tight Clothing: Men's briefs and tight pants have been thought to have the same effect on sperm as heat exposure and hot baths, however there is no scientific evidence for this hypothesis.
Birth Control: Hormonal methods of birth control can lead to temporary infertility. The IUD puts women at risk of PID which can cause infertility, especially among non-monogamous couples. As expected, surgical sterilization will usually cause infertility and should be considered permanent. Multiple abortions are also linked to impaired fertility.
- For reproductive news, research and medicine, there's The American Society for Reproductive Medicine