Building a baby: through the food she eats, the pregnant woman provides nourishment to her unborn baby.

BUILDING A BABY

Through the food she eats, the pregnant woman provides nourishment to her unborn baby.

Pregnancy should be a delightful time of anticipation. Will the baby be a boy or a girl? What will we name it? When will it be born? Today's scientific and technologic advances may be able to tell us if its a boy or a girl and medical science may even determine when the baby will be born, but mother still has an important role to play in supplying the raw materials to "build the baby."

The unborn baby is influenced by what happens and what has happened in the mother's life. She passes on to her child her own nutritional heritage, her practices, and her beliefs; her child in turn passes them on to the next generation.

Probably no other time in life is surrounded with so many old wives' tales as is pregnancy. Until this century very little was known about the nutrients in foods. Thus, food advice given to pregnant women was often based on the physical properties of foods. For example, women were told not to eat acidic or sour foods or the baby would have a "sour" disposition. On the other hand, warm milk, broths, and ripe fruits were said to soothe the fetus.

Advice given to pregnant women was also based on the problems commonly seen in obstetrical practice at the time. During the Industrial Revolution children worked long hours in dark factories and had poor diets. As a result, rickets, a nutritional disorder that impairs bone formation, was common. Women with a small pelvis because of this disorder were at great risk during childbirth. The death rates of both mothers and babies were very high.

In the 1880s a German physician told his pregnant patients to restrict their diet and fluid intake during the last six weeks before the baby was born. The babies were then smaller and were easier to deliver from women with a small pelvis. This advice may have had some justification for women throughout pregnancy, and remained long after the reason for it was gone. Remnants of such dietary advice still exist today, even though we know a great deal more about what happens during pregnancy.

Physiologic changes. A number of changes take place in the mother's body during pregnancy. These changes affect almost every function in the body and are intended to support the pregnancy and help the baby grow appropriately. These changes affect the nutrient needs of the mother.

The blood volume begins to increase by the end of the first trimester, and by the thirty-fourth week of pregnancy it is increased 50 percent. This increase in blood volume is important to pregnancy outcome. Women who have a smaller increase compared with the average are more likely to have stillbirths, abortions, and low-birth-weight babies. The increased blood volume is important so nutrients can be delivered to the placenta for its own growth, as well as for delivery of nutrients to the fetus. Nutritious food is necessary to support the increase in blood volume.

The gastrointestinal system also undergoes changes during pregnancy. The appetite increases. Nausea and vomiting may also occur. Progesterone, one of the hormones produced in larger amounts during pregnancy, reduces the tone and motility of the smooth muscles of the gastrointestinal tract. These changes may result in heartburn as well as contribute to constipation. Usually these effects are relatively minor, but if they persist or are extreme, they will need medical attention. Often there are food practices that can be adjusted and will help to relieve the symptoms.

"Morning sickness," the nausea and vomiting that occur more often in the morning than later in the day, is usually mild and limited to early pregnancy. Small frequent meals are often suggested. They should be fairly dry and contain mostly easily digested carbohydrate foods such as plain pasta, crackers, potatoes, rice, fruit, and vegetables. It is best to drink liquids between meals. Avoid strong cooking odors and spicy and high-fat foods. It may be helpful to eat crackers or dry toast before you get out of bed, to start the digestive processes and remove acid from your stomach. Getting up slowly is also helpful.

Constipation may result from the increased relaxation of the gastrointestinal muscles and the pressure of the enlarging uterus. Increasing fluid intake and using naturally laxative foods such as vegetables and fruits, especially dried fruits such as prunes and figs, generally helps. Walking is also helpful. These suggestions will help prevent hemorrhoids, as well. Laxatives should be used only under medical supervision.

Pregnant women sometimes complain of "heartburn," especially after a meal. This is caused by the enlarging uterus crowding the digestive organs. It may help to eat smaller meals and avoid too much food at any time. Avoid highly seasoned, rich, and fried foods. Try to relax; take time to eat slowly, and avoid tensions during meals. Lying down after eating may make symptoms worse, but taking a walk will encourage the gastric juices to go down rather than up. Loose-fitting clothing may also be helpful.

Dental health should not be neglected during pregnancy. The recommendations to eat smaller, frequent meals of easily digested carbohydrate foods to help lessen morning sickness and heartburn may increase the potential for dental decay. It is also common for the changing hormonal climate during pregnancy to cause increased swelling and bleeding of the gum tissue. Regular brushing and the use of floss will help to maintain a healthy mouth.

Nutrient needs in pregnancy. Food fulfills many social and cultural functions, but in pregnancy it takes on even more important roles. Through the food she eats, the pregnant woman provides nourishment to her unborn baby. The food she eats supplies the energy and nutrients for the increasing blood supply, the enlarging placenta, and the developing fetus, as well as increases in maternal tissues. All these components contribute to the weight that is gained during pregnancy.

In addition to the seven and one-half pounds contributed by the fetus, the average placenta weighs one pound and the amniotic fluid two pounds. Breast tissue increases by three pounds and the increases in blood volume add another four pounds. Maternal stores add four to eight pounds.

It is normal and desirable for the pregnant woman to build reserves. These stores help sustain the baby's rapid growth in the latter part of pregnancy. They provide energy for labor and delivery, and for breast feeding. Dietary restrictions placed on pregnant women can result in smaller maternal stores and smaller babies.

Scientists estimate that it takes more than 60,000 calories in addition to the ones the mother needs, to develop a healthy baby. This means that after the first trimester, the mother should eat an extra 300 calories a day above the nonpregnant intake. However, energy needs and weight gains that will support a healthy pregnancy differ a great deal and are influenced by many factors.

Two factors that can influence the weight of the baby are the mother's prepregnancy weight and weight gain during pregnancy. Women who are at their normal weight at the beginning of pregnancy and who gain 25 to 35 pounds have fewer problems than normal-weight women who gain more or less.

Women who are underweight at the beginning of pregnancy have a greater risk of having a low-birth-weight baby and of having premature labor. It is recommended that they gain 28 to 36 pounds.

On the other hand, the woman who is overweight at the start of pregnancy may be advised to gain slightly less. However, pregnancy is not the time for weight reduction. Nor is it the time for meal skipping. It is a good time to concentrate on improving the quality of the diet and making sure that all the calories count.

The weight should increase at a steady pace. A weight gain of two to four pounds can be expected by the end of the first three months. During the rest of pregnancy, weight gain should continue at about a pound a week. A sharp increase in weight gain may indicate abnormal fluid retention and should be monitored by the physician.

Some women use pregnancy as a time to eat anything they want without regard to nutritional quality. "After all," they say, "I'm eating for two." It is true that the food the mother eats supplies the nutrients for herself and the developing baby. But during pregnancy the increased need for energy is relatively small compared to the increased need for various nutrients (see accompanying table). This means the mother must give special attention to choosing foods that supply those nutrients without adding more calories than are needed.

Table : Percentage increase in nutrient needs during pregnancy, based on the 1989 RDA.

Energy    14%
Folate   120%
Thiamin   36%
Calcium   50%
Iron     200%
Zinc      25%

One way to do this, especially if the mother is gaining weight more rapidly than advised, is to cut down on foods that are high in sugar and fat. Such foods include cakes, cookies, pastries, candy, and rich desserts. Another way to avoid unnecessary calories is to limit rich sauces. Learn to appreciate vegetables prepared simply, perhaps seasoned with herbs. Substitute skim or lowfat milk, yogurt, and cheese for the whole-milk products. This will cut down on fat and calories while you still obtain the important nutrients these foods provide. Baking or broiling foods instead of frying them also decreases fat and calories.

Several nutrients deserve special mention. Fat- and carbohydrate-containing foods supply the needed energy. However, most of the energy should come from carbohydrate sources. The developing baby needs a constant supply of energy, and carbohydrates can quickly and easily supply that need. Emphasis should be on foods rich in complex carbohydrates and unrefined cereals and grains.

Protein supplies the amino acid building blocks for cells and tissues in the growing baby and the mother's body. Obtaining enough protein is generally not a problem in America. Concern with protein sometimes obscures the emphasis that should be given to other nutrients.

Folic acid is necessary for DNA synthesis, and DNA is, of course, necessary for new cells to be made. Thus, the need for folic acid is greatly increased during pregnancy, when the body is making many new cells. A number of studies have investigated the relationship between folic acid status and pregnancy outcome. Although there is no direct proof of a cause-and-effect relation, the evidence suggests that a deficiency is associated with abruptio placentae, spontaneous abortion, preeclampsia, fetal malformations, and subnormal infant development.

Recent reports suggest that prenatal vitamin supplementation is beneficial in helping to prevent some of the effects associated with low folate levels. However, not all studies arrive at the same conclusions, and pregnant women or those contemplating pregnancy should seek the advice of their physician.

In addition, it is very important that large doses of vitamins and minerals be avoided. Large doses of vitamins A and D have been associated with fetal malformations. Pregnancy is not the time for indiscriminate use of vitamin supplements. Rather, the pregnant woman should learn good food sources of the various nutrients and be sure that her diet contains foods that will supply the nutrients she needs in appropriate amounts.

Vitamin [B.sub.12] is of special interest because it is not found in the plant foods usually eaten. It is of course found in animal products. In recent years a number of cases of [B.sub.12] deficiency have been reported in infants who received no food other than breast milk from mothers who were total vegetarians - that is, they ate no animal products. One of the infants appeared not to recover completely after he was given the vitamin. Because a deficiency can result in irreversible neurologic damage, it is very important that the pregnant woman who is a total vegetarian makes sure she has a source of this vitamin.

Some claim that tempeh and similar foods contain [B.sub.12]. It has been shown that the form in such foods is not active in humans. There is some of the active form in certain seaweeds. The vitamin is found in some soy-milk products and other fortified foods. However, read the label. If it says "cyanocobalamin," you can know that it is the active form. If it says "vitamin [B.sub.12]," it may contain forms that are inactive for humans. The spirulinas sold in health food stores contain almost none of the active form.

We will mention just two more of the many other nutrients also needed: iron and calcium. If the pregnant mother does not get enough iron and calcium, the growing baby will use iron from the mother's blood and calcium from her bones for its own use. Thus, the mother should make sure she gets enough of these nutrients.

Iron, as well as folate and vitamin [B.sub.12], is needed for the production of red blood cells. Providing enough of these nutrients is important to support the expanding blood volume and growing tissue needs. Because many women enter pregnancy with low iron stores and because iron is found in low amounts in usual diets, a supplement is often recommended. Nonetheless, iron-rich foods should also be emphasized.

Lean red meat and liver are often recommended as iron sources. This is because the iron from these foods is more readily available than iron from plant foods. However, many people prefer not to eat meat; plant foods such as green leafy vegetables, dried fruits, enriched cereals and breads, and legumes contribute iron. The availability of the plant food iron can be increased by eating a vitamin C-containing food at the same meal. A healthy practice for everyone is to be sure there is a good source of Vitamin C in every meal.

Calcium has attracted a lot of attention in recent years. It is important for young women to eat enough calcium-containing foods to build strong bones that will support them even when some of the mineral is lost in later years. Recent studies suggest that if the pregnant woman does not eat enough calcium, it will be taken from her bones to meet the needs of the growing baby. Other studies suggest that the bone density in the newborn is affected by adequacy of the mother's calcium intake.

Milk and dairy products are important dietary sources of calcium. It is also found in legumes, nuts, dried fruits, and some dark-green leafy vegetables. Calcium in spinach, chard, and beet greens is bound to oxalic acid and is unavailable, but the calcium in kale, cabbage, collards, and turnip greens can be utilized by the body.

The pregnant mother is truly building a baby. The food she eats provides the raw materials. Too often we think that a woman becomes a mother when the baby is born. But there is a great deal of mothering that goes on during the nine months of pregnancy. Being a mother is often associated with providing food for the children. In a very real sense the pregnant mother is supplying food for her growing baby. Care in choosing the very best foods will help assure that the baby will receive all the nutrients it needs.

Patricia K. Johnston, Dr. P.H., M.S., R.D., is director of the Doctor of Public Health program and associate professor of nutrition at Loma Linda University, Loma Linda, California.