Trying to Outsmart Infertility

by Food and Drug Administration (FDA)

The human female is born with about a million eggs — all that she will ever have. Beginning with the onset of menstruation in adolescence and continuing until menopause, her hormones prepare one or two of these eggs for possible fertilization each month. The human male, starting at puberty, makes many millions of sperm a day for the next 50 years or more. Biology, it would seem, generously equips both sexes for parenthood. Yet the National Center for Health Statistics reports that roughly 1 of every 12 American couples that tries to have a baby fails.

Sometimes, the problem is simply impatience. Medically speaking, a couple generally isn't termed infertile unless there is still no baby on the way after at least a year of regular intercourse without using any form of birth control.

The odds are sharply against conception most of the time. A woman has just a 20 to 35 percent chance of conceiving during each menstrual cycle, even at the peak of her fertility, and that starts to decline slightly in her late 20s and early 30s and more steeply after about age 35. For the many members of the baby boom generation in particular who are late in trying to start families, getting pregnant is not necessarily as easy as the proverbial fall off a log.

The other variable in the childbearing equation is male fertility, which, like female fertility, declines with age, although more slowly.

Fertility is impaired in as many men as women. More specifically, according to Robert D. Visscher, M.D., medical director of the American Fertility Society, the problem lies entirely with the man in about a third of infertile couples and entirely with the woman in about another third. In another group of such couples — some 15 to 20 percent of the total — the fertility of both the man and the woman is below par. There are, besides, couples in whom nothing can be found in either partner to explain the reproductive difficulty. Would-be parents can therefore avoid a lot of heartache by thinking of infertility as "our" problem rather than "mine" or "yours."

Health professionals, too, are coming to recognize the importance of this no-fault philosophy. "The realization that the infertile couple is a unit is probably the greatest advance medicine has made in this field," said Elwyn Grimes, M.D., a Kansas City, Mo., reproductive endocrinologist who serves on a Food and Drug Administration obstetrics and gynecology advisory panel. "When a couple is having trouble having a baby and decides to try to do something about it, it makes no sense to evaluate one partner and not the other. Besides, efforts to overcome infertility require the cooperation of both partners and so put both under considerable emotional stress."

Perhaps most stressful of all is the knowledge that those efforts may come to naught. Systematic studies to determine how often treatment results in a successful pregnancy have not been done. But the consensus of the experts, says the American Fertility Society's Visscher, is that the success rate is, typically, in the 50 percent range. Moreover, a pregnancy is no guarantee that a baby will be born. There is always the possibility of a miscarriage or other complication during the nine months of gestation that will leave a couple with a cradle as empty as before.

Identifying Stumbling Blocks

The mishaps that can befall a pregnancy aside, the biology of setting one in motion is itself enormously complex. (See diagram.)

Pregnancy cannot occur unless it is preceded by a long series of hormonally controlled interactions that separately prepare sperm and egg for their missions. A woman will not conceive unless her partner is able to deposit semen in her vagina and his sperm are sufficiently vigorous so that at least one can swim into her fallopian tubes to fertilize a waiting egg. (Each of the two ovaries has its own fallopian tube that leads to the uterus. Because the ovaries normally take turns releasing an egg, each of the tubes normally has an egg in it every other month.)

At the same time, the female must be in hormonal readiness to permit egg and sperm to unite when they meet in the tube, and the tube must be open from end to end. In addition, the muscle of the tube and the eyelash-like hairs on its lining (called cilia) must have enough strength and range of motion to sweep the egg into the uterus after it is fertilized. Even then, the fertilized egg will die if it does not implant in the lining of the uterus and if that lining — which is also under hormonal control — is unable to sustain it.

The considerable progress made in identifying the stumbling blocks to conception is the bedrock of advances in treatment, but the solutions are, occasionally, surprisingly simple. It sometimes turns out, for example, that a couple has not realized that a lubricant they have been using also contains a spermicide. Or it may be that unknowingly they have been making love either in a position unconducive to conception or during a time of the month when the woman's egg is not ripe for fertilization. Still another possibility is too frequent intercourse. (It usually takes 48 hours after ejaculation for semen to again have a full complement of sperm.)

Thorough physical examinations, a family health history, and batteries of diagnostic tests are, nonetheless, essential to most infertility evaluations. (See accompanying article, "Infertility Tests.") Some causes of infertility require only lifestyle changes. Some women don't menstruate, for example, because they exercise too vigorously or have anorexia or another eating disorder that has made them far too thin. For them, less activity or a more nutritious diet leading to weight gain may do the trick.

In men, reduced sperm activity may result from wearing clothing that keeps the testes too warm (jockey shorts, for instance, instead of boxer shorts). Sperm quality can sometimes be improved and fertility attained by wearing a water-cooled testicular hypothermia device, available by prescription, that FDA has approved for lowering the temperature of the scrotum.

Fertility Drugs

Deciding what to do, if anything, when the evaluation is complete may not be easy. Assuming these problems are treatable — and not all of them are — there is a bewildering array of choices, especially for women, and no guarantee that any of them will work. So it is that specialists in this field speak of "maximizing fertility potential" rather than "curing infertility."

Fertility potential starts in the brain, in an area called the hypothalamus. In both men and women, a hormone made by the hypothalamus travels via the blood to the pituitary gland at the base of the brain. This gland in turn makes hormones of its own that circulate in the blood and act on the reproductive organs.

In males, the message received by the testes causes them to make still another hormone, testosterone, which is their signal to make sperm. In females, an analogous cascade of hormones distributed by the bloodstream plays an equivalent role in ensuring that the right chemical messages get to the right places at the right times to allow women to ovulate and conceive.

When blood and urine tests of an infertility workup suggest some sort of hormone imbalance in one or both partners, corrective therapy with so-called fertility drugs is frequently prescribed. The most popular of these drugs are Clomid and Serophene (both clomiphene citrate in tablet form), which act on the hypothalamus, and Pergonal (human menopausal gonadotropins), which acts on the pituitary gland.

Because these powerful drugs can have a wide range of side effects, patients should always discuss the pros and cons of their use with the physician in advance. Clomid and Serophene, for example, can prolong the menstrual cycle and so make a woman mistakenly think she has conceived. Moreover, there is a risk with some fertility drugs of multiple births. Even if the couple would welcome several babies, multiple births can complicate pregnancy and delivery and endanger infant survival.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.