Nutritious Expectations

Nutritious Expectations
January 1999 -- Nutrition Notes

By: Andrea Platzman, R.D.
Contributing Editor

  Of the four million American women giving birth annually, six in 10 experience some health problems during pregnancy or delivery. Nutrition is one of the best tools to help ensure a healthy pregnancy.

  "The need for all nutrients increases during pregnancy, especially for iron, folate, zinc and calcium," says Madeleine Sigman-Grant, Ph.D., R.D., MCH specialist and professor, University of Nevada Cooperative Extension, Las Vegas. "Calories and protein also increase, but only in amounts equivalent to a peanut butter sandwich and a glass of milk." The total "cost" of pregnancy is about 80,000 calories above usual needs - approximately 300 extra calories a day over nine months, or 2,500 total calories each day for the average woman.

Macronutrient requirements

  Fuel for a healthy pregnancy comes from carbohydrates, protein and fat. Most calories consumed during pregnancy should come from carbohydrates, which the body can utilize efficiently to meet energy demands. The baby's nervous system needs glucose produced from carbohydrates to develop properly. Foods rich in complex carbohydrates also contain other important nutrients, such as B vitamins, vitamin C and fiber. Fiber helps alleviate constipation, a common problem during pregnancy.

  Pregnant women need about 60 grams of protein daily, an increase of 10 to 15 grams. Protein, with its essential nitrogen, is crucial not only for the baby's tissue growth, but also for enlarging the mother's uterus, mammary glands and placenta; increasing the mother's circulating blood volume; and forming amniotic fluid and storage reserves for labor, delivery and lactation.

  Fats are particularly important when expecting. Dietary fat, the sole provider of essential fatty acids (linoleic and linolenic), is pivotal to proper development of the baby's brain and central nervous system. In addition, fat helps transport vitamins A, D, E and K. Since blood-cholesterol levels tend to rise during pregnancy, polyunsaturates (safflower, soybean or corn oils) and monounsaturated fats (olive oil, avocado, peanut butter) are recommended. Also important are the omega-3 fatty acids from seafood, essential for normal development of the fetus' eye function and vision.

Vitamin and mineral needs

  Vitamins and minerals aid metabolism, digestion and absorption of macronutrients, as well as orchestrate many other processes in the body. Since folic acid plays such a critical role in cell development, women need more than usual during pregnancy. Research shows that taking folic acid before pregnancy and during early pregnancy can reduce the risk of low birth weight and neural-tube defects, such as spina bifida. It is recommended that any woman capable of becoming pregnant consume 400 µg of folic acid daily (twice the normal intake). Folic acid also is vital for new and healthy red blood cells, and deficiency can leave the expecting mother anemic.

  Iron also plays a critical role in building red blood cells and hemoglobin, which carries oxygen and makes it available to cells. Over the course of pregnancy, the mother absorbs an extra 1,000 mg of iron, and daily requirement doubles from 15 mg to 30 mg. Additionally, the mother's blood volume increases by about 50%, and the baby needs iron to build his or her own blood cells. The body absorbs heme iron, found mostly in animal foods, better than nonheme iron. Consuming foods rich in vitamin C with meals helps boost heme and nonheme iron absorption.

  A mom-to-be needs enough calcium during pregnancy to meet her own needs as well as the baby's for constructing healthy bones and teeth. Some studies show that proper calcium levels help prevent high blood pressure and toxemia. "Calcium is an important concern, especially with pregnant teens, since they do not drink much milk," explains Sigman-Grant. "To meet the additional calcium needs, foods such as calcium-fortified orange juice are a good choice." The baby gets the calcium he or she needs from the mother's bones. To compensate for this loss, vitamin D helps the body absorb more calcium from food and deposit it in bones. "Even though the RDIs for calcium increased for women, the amount doesn't change for pregnant women, because the rate of absorption increases during pregnancy, making the current calcium recommendation of 1,500 mg (about three to four glasses of milk daily) more realistic."

  Pregnant women require 10 µg or 400 international units of vitamin D daily. The body can synthesize vitamin D from sunlight, although sun-protection-factors greater than eight block most of the rays initiating vitamin D production.

Special food concerns

  Sugary foods, while tasty, provide little nutrition. "Sugar is fine in moderation, provided that the mother is not a gestational diabetic," says Laurie Green, M.D., Pacific Women's Obstetrics and Gynecology Medical Group, San Francisco. Artificial sweeteners approved by FDA - aspartame, saccharin and acesulfame-K - are considered safe for moderate consumption during pregnancy.

  Sodium helps the body retain water, and is necessary for normal muscle contraction and nerve conduction. Reducing sodium in the diet can interfere with expansion of the mother's blood volume - critical to supplying the baby with nutrients. However, a consistently high sodium intake can interfere with calcium absorption. A minimum of 570 mg of sodium is required during pregnancy, but an average of 3,000 mg is a good goal.  Coffee consumption during pregnancy is controversial. "Caffeine in moderation, about 400 mg, can be consumed safely," Green explains. "The studies linking caffeine to miscarriage were poorly done. Until a study is done force-feeding caffeine to huge numbers of women, and then checking the outcome, one cannot assume that caffeine adversely affects pregnancy." Whatever its other effects on pregnancy, caffeine is a diuretic causing loss of water, which can lead to dehydration.

  No amount of alcohol is safe during pregnancy. Some experts maintain that just one drink a day can lead to fetal alcohol syndrome (FAS). Babies born with FAS are abnormally small, and lack fully developed brain tissue. They may also have heart defects and other abnormal internal organs.

  These macronutrient, vitamin and mineral recommendations are for the average expecting woman. If below weight at the time of conception, a woman will require more calories, just as if she were overweight, she would require fewer. In addition, teen-age pregnant women and active pregnant women have different nutrient requirements.

  Andrea D. Platzman is a registered dietitian who is a consultant to the food industry, and regularly writes for nutrition publications. She earned a master's degree in nutrition from New York University, and has a culinary and business background.

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