Health Conditions

What is on the horizon?

Much of the current research on infertility involves its causes and the conditions that may contribute to it, in addition to new treatments. For example, fertility researchers at the National Institute of Child Health and Human Development (NICHD) have been looking at several general factors involved in human fertility that include:

• Structures of both male and female reproductive tracts
• Actions of the hormones that regulate fertility
• Functions of the ovaries and testicles
• Mutations of genes responsible for reproductive functions

Researchers continue to try to find ways to improve current treatment options such as assisted reproduction techniques. For example, a screening method known as preimplantation genetic diagnosis (PGD) is being developed and tested so that doctors may identify which embryos are the highest quality for transfer to a woman during in-vitro fertilization.

Aging

In addition, investigators are trying to understand why fertility decreases as a woman ages and how to slow or stop this process. There is also the possibility of a woman being able to freeze her eggs for future use if she wishes to delay pregnancy until she is older.

Uterine Transplantation

Another alternative that is currently being studied is uterine transplantation. This treatment would be an alternative to using a surrogate mother (a healthy woman who agrees to have the fertilized egg or eggs implanted in her uterus). However, like other transplant patients, uterine transplant patients would require drugs to prevent the immune system from rejecting the donor organ. These drugs often have unwanted side effects and need to be taken for life. Although some progress has been made with this and other new treatment options, it is unlikely that they will be widely available to women anytime soon. It will take many years to determine whether these new treatment options are safe and effective.

Nutritional Factors

Other research has uncovered possible nutritional factors that may contribute to infertility that is not explained by physical or emotional factors. For example, low levels of folic acid, a type of vitamin B found in fruits, vegetables and other foods, may be associated with infertility in men. Folic acid has long been known to help prevent birth defects of the spine when pregnant women take it, and taking it may improve female infertility, too. Trace elements are chemicals such as aluminum and zinc that the body needs in very small amounts. Shortages of some of these trace elements are also believed to decrease fertility. Zinc deficiencies may contribute to genetic damage that may result in both male and female infertility because zinc is a component of DNA. One study of infertile men has shown a significant increase in sperm production among men who took supplements containing folic acid and zinc. Essential fatty acids (EFAs) are needed by both men and women to make sex hormones and they may have effects on semen and cervical mucus. Other dietary supplements, such as carnitine (found in meat and milk) and melatonin, have been tested for their effects on infertility in men. Results of studies on the role of nutrients and dietary supplements in infertility are not conclusive.

Antioxidants

Frequently called reactive oxygen species (ROS), oxygen free radicals are highly-active molecules that result from normal body processes. Inside the human body, oxygen free radicals may cause damage to other cells including sperm and eggs. They may also contribute to infertility risk factors, such as endometriosis. Antioxidants, for instance beta carotene, selenium, and vitamin C, are substances that help to limit damage from oxygen free radicals. Studies conducted in Australia and India suggest that naturally-occurring antioxidants such as lycopene seem to help improve fertility in men. Research on the effects of oxygen free radicals on fertility in women is less advanced, but studies are underway for both men and women.

Cancer and Infertility

For individuals who may become infertile due to radiation or chemotherapy treatments for cancer or other diseases, sperm or eggs may now be collected before the therapy begins. In a procedure known as cryopreservation, healthy sperm or eggs are taken from the patient and frozen, before therapy begins. After the damaging treatment, the eggs or sperm may be used for ART procedures. More recently, cells from testicles and ovaries have also been cryopreserved and then re-implanted to restore at least partial reproductive function after treatments are ended. Doctors may also use infertility medications to minimize reproductive organ damage during cancer treatment. In a procedure that is beginning to be used more frequently for children, adolescents, and young adults, FSH and LH levels may be suppressed by drugs known as GnRH analogs during the cancer treatment. As a result, the testicles or ovaries become inactive and, therefore, less likely to be damaged by drug or radiation treatments. After the therapy is over, at least partial normal function may be restored.

Long-term Effects of ART

Finally, researchers are focusing on the long-term effects of ART on all members of the family. If ART is not successful, both partners may suffer psychological consequences, such as depression and loss of self-esteem. Procedures that result in live births - especially those producing three, four, or more babies at the same time - often create unexpected physical, financial, and emotional stresses for the family. Frequently, ART procedures produce multiple-infant pregnancies and women pregnant with more than one child are more likely to develop complications during pregnancy. Both multiple and single children born after ART are more often delivered early. They also tend to be lower in birth weight than other babies. Being born early and/or weighing less than five and a half pounds at birth may contribute to breathing, heart, intestinal, and vision problems. In addition, results of a few studies seem to show that some children born as the result of ART may be at a slightly greater risk of having certain birth defects, developmental abnormalities, genetic conditions, or learning disorders than children who are conceived naturally. Whether the tendency to have these conditions is due to ART, to the factors causing the infertility, or to other causes has yet to be determined.