The Perplexities of Pregnancy

by Food and Drug Administration (FDA)

There's a new baby boom in the United States. Last year more than 4 million babies were born, according to the U.S. Department of Vital Statistics.

Accompanying this steadily increasing birth rate (up 250,000 from 1985) is an abundance of continually updated information for mothers-to-be, on everything from nutrition to the use of aspirin. Keeping current with this information can often leave the expectant mother perplexed.

The ideal time to begin learning about pregnancy is before becoming pregnant. However, if this is not possible, once pregnant, a woman should consult a health-care professional trained in obstetrics.

Home Pregnancy Tests

Many women use home pregnancy tests if they suspect they're pregnant. Regulated by the Food and Drug Administration, pregnancy tests have come far since the early to mid-1900s when toads, rats and rabbits were used in testing. Now, over-the-counter home pregnancy kits provide privacy and fast results, and can detect pregnancy as early as six days after conception, or one day after a missed menstrual period. This gives an early advantage for vital prenatal care.

All pregnancy tests are based on the presence of a hormone, human chorionic gonadotropin (HCG), that the pregnant woman produces after conception. The first self tests of the 1970s used ring, or "tube agglutination," tests consisting of prepackaged red blood cells to detect HCG in urine. A ring at the bottom of the tube indicated a positive result. Sensitive to movement and human error, ring tests are now rarely used.

Today's brands, such as e.p.t. and First Response, contain monoclonal antibodies that detect minute traces of HCG. These antibodies are molecules coated with a substance that bonds to the pregnancy hormone, if it's present, to produce either a positive or negative result. (Each test manufacturer uses a different "trade secret" chemical formula for the bonding substance.) The user collects urine and combines it with the antibodies provided in the package. The test is timed, and a color change indicates the result.

Although most manufacturers claim 99 percent accuracy in laboratory tests, inaccurate results may be more frequent in actual use, due to such factors as improper use of the test, using a product past its expiration date, exposure of the test to the sun, and cancers. The procedures outlined in the instructions must be followed exactly for results to be accurate.

Whitehall Laboratories markets the newest one-step brand, Clearblue Easy. It gives results in three minutes and informs the user when the test hasn't been done properly. This new testing method, called rapid assay delivery system, combines a biochemical process with monoclonal antibodies in one pen-like instrument.

Whatever the result or the brand used, most manufacturers recommend repeating the process a few days later to confirm the results. After conception, a woman produces a minimal amount of HCG. The strength of each test varies, and although a woman may be pregnant, the test may not pick up the amount of HCG hormone present the first time.

Nutrition and Supplements

Even before pregnancy begins, nutrition is a primary factor in the health of mother and baby. A well-balanced diet before conception contributes to a healthy pregnancy and will probably need few changes.

According to the American College of Obstetricians and Gynecologists, pregnant women should increase their usual servings of a variety of foods from the four basic food groups to include a total of four or more servings of fruits and vegetables, four or more servings of whole-grain or enriched bread and cereal, four or more servings of milk and milk products, and three or more servings of meat, poultry, fish, eggs, nuts, and dried beans and peas.

These additional servings will help meet the recommended daily allowances (RDAs) of nutrients required to maintain good health. These RDAs from the National Research Council were updated in 1989. The accompanying chart outlines the requirements of vitamins and minerals during pregnancy.

Often, nutritional supplements are provided for pregnant women, but according to a June 1990 report released by the Institute of Medicine (IOM), studies found these supplements to be of little or no value. Most physicians agree that RDAs, except those for iron, can be obtained through a proper diet.

Iron is needed in larger doses, especially in the later stages of pregnancy, and cannot be met by diet alone, according to the National Research Council. This mineral is essential to the formation of healthy red blood cells, and it is difficult for a woman to consume enough of it from foods to maintain an adequate supply for herself and her fetus. Without enough iron, the fetus will draw its supply from the mother, often leaving her anemic and exhausted. An iron supplement can alleviate this condition.

In certain studies, the vitamin folacin has been shown to be important in preventing neural tube defects, such as spina bifida. The need for folacin more than doubles during pregnancy, from 180 micrograms to 400 micrograms. Like iron, folacin is essential to the formation of red blood cells. However, the IOM panel found insufficient evidence to recommend that all women take supplements containing folate, which can be found in liver, kidneys, leafy green vegetables, and dried beans and peas.

Other research questions whether there may be some benefit from multivitamins in preventing neural tube defects. The U.S. Centers for Disease Control reported a study of women who took multivitamin pills three months before and three months after conception. Researchers found a slightly higher incidence of birth defects in babies of women who were not multivitamin users. However, it is unclear whether the increase of defects was due to a lack of vitamins or to other factors that were not measured.

Although some subsequent studies showed that taking a daily multivitamin helped decrease birth defects, other studies showed multivitamin intake had no relationship to the incidence of birth defects. However, it is known that very high intakes of vitamins, such as vitamin A, may increase the occurrence of birth defects.

While research continues, the IOM recommends supplements only for pregnant women who are smokers, drug users, alcohol drinkers, or strict vegetarians. Obstetricians will continue to make the decision to recommend supplements based on individual requirements and will not recommend megavitamin supplements without a specific medical reason.

About the Author

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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.