Ivy had been eating tuna sushi almost every day. But before becoming pregnant, she wisely had a check-up, which revealed high levels of mercury in her blood that could damage a foetus. She stopped eating tuna and postponed pregnancy until the mercury had cleared from her system. Last month, she gave birth to a full-term healthy boy.
Mercury from eating certain kinds of seafood is just one of many nutrition-related hazards that can confront a pregnant woman or one who wishes to become pregnant. At the same time, some pregnant women worry needlessly about non-existent nutritional risks.
The March of Dimes, a non-profit organization in the US, which strives to make every pregnancy as well-planned and successful as Ivy’s, is pushing anew to dispel nutritional misinformation and replace it with advice based on solid scientific evidence. Some of the advice may come as a distressing surprise to women, who may be fond of foods or drinks that could endanger their pregnancy.
A healthy diet
Pregnant women are advised to steer clear of deli meats, including sliced turkey, unless these are fully cooked again before being eaten.
Experts say it is safe to drink one or two cups of caffeinated coffee a day during pregnancy, but consuming too much herbal tea (and three or more cups of coffee a day) may result in a miscarriage.
The organization is also concerned about the current notion among some women that it is all right to gain 40 pounds (18.15kg) or more when pregnant with one baby. Excessive weight gain in pregnancy not only makes it harder to shed the extra pounds after childbirth, it also increases the risk to the mother of gestational diabetes, dangerous rises in blood pressure (pre-eclampsia), the need for a Caesarean delivery and post-partum infection. For the baby, a mother’s excessive weight gain raises the risk of neural tube defects, birth trauma and foetal death near term.
Studies of tens of thousands of pregnancies have shown that the amount of weight a pregnant woman should gain for the best chance of a healthy outcome for both mother and baby depends on how much she weighed before becoming pregnant.
Accordingly, the March of Dimes suggests that normal-weight women should gain 25-35 pounds (11.34-15.88kg); overweight women, 15-25 pounds (6.8-11.33kg), and underweight women, 28-40 pounds (12.7-18.14kg). A woman having a multiple birth should gain more, depending on the number of babies.
An ideal time to learn the principles of good nutrition and put these into practice is when a woman is eating for two or, better yet, when she is contemplating getting pregnant. The basics of a healthy diet during pregnancy are the same as what everyone should eat at any time of life:
• Whole grains, such as brown rice, whole wheat bread or whole oat cereal: 6-11 servings a day.
• Dairy products, such as low-fat or non-fat milk, yogurt or hard cheese: 3-4 servings a day.
• Protein, such as meat, poultry, fish, beans, nuts and eggs: 3-4 servings a day.
• Vegetables, such as broccoli, carrots, green beans, tomatoes and beets: 3-5 servings a day.
• Fruits, such as oranges, bananas and apples: 2-4 servings a day.
The trick is to know what a portion means because “eating for two” does not mean a woman should double her caloric intake.
Only 300 additional calories a day are needed to sustain a healthy pregnancy, provided those calories come from nutritious foods.
Here are some examples of single serving: One slice of bread, a half-cup of rice or pasta, one cup cold cereal; one cup milk or yogurt, two one-inch cubes of cheese; two ounces (57g) of cooked meat, poultry or fish, a half-cup of cooked dried beans, two tablespoons peanut butter; a half-cup of cooked or cut vegetables, one cup of salad greens, three-quarters cup of vegetable juice; one apple, banana or orange, a half-cup of cut fruit, three-quarters cup of fruit juice.
Be sure, too, to drink plenty of water and get regular exercise. Pregnant women can walk, dance, swim and do yoga, but should avoid high-risk activities such as scuba diving and skiing.
Foods to avoid
Many popular foods are potentially dangerous during pregnancy. Experts say that pregnant women should refrain from the following:
• Raw fish and shellfish, a probable source of the parasite toxoplasma, which can cause foetal blindness as well as brain damage.
• Large predatory fish, such as swordfish, shark, king mackerel and albacore tuna (fresh or canned), which can contain risky levels of mercury. The food and drug administration says albacore tuna should be limited to 6 ounces (170g) a week, but it is acceptable to eat up to 12 ounces (341g) a week of light tuna, shrimp, salmon, pollock and catfish.
• Undercooked or raw meat, poultry and seafood. Use a meat thermometer and cook pork and ground beef to 160 degrees (71°C), beef, veal and lamb to 145 degrees (62.7°C), whole poultry to 180 degrees (82°C) and chicken breasts to 170 degrees (76°C).
• Unpasteurized milk and soft cheeses—feta, Brie, Camembert, Roquefort, queso blanco, queso fresco and Panela—unless the label says “made with pasteurized milk”.
They may contain the food-poisoning bacteria listeria that can cause miscarriage, premature birth, stillbirth or fatal newborn illness.
• Hot dogs and deli meats, unless cooked until steaming hot. These can become contaminated with listeria after processing.
• Refrigerated pâtés, meat spreads and smoked seafood (unless these are cooked before you eat these). Canned versions are safe.
• Soft scrambled eggs and foods such as home-made salad dressing and eggnog made with raw or lightly cooked eggs. Cook eggs until the white and yolk are firm to avoid salmonella poisoning.
• Raw sprouts, including alfalfa, clover, radish and mung bean.
• Herbal teas and supplements. Their safety during pregnancy has not been studied. Some, such as black cohosh or large amounts of chamomile tea, can raise the risk of miscarriage or premature birth.
• Alcohol, which can cause foetal damage, including mental retardation and abnormal behaviour.
Although experts do not frown upon an occasional drink, no safe amount has been established for pregnant women yet.
Extra vitamins needed
Pregnant women and those contemplating pregnancy are advised to take a daily prenatal vitamin that contains 400-600 micrograms of folic acid to help prevent neural tube defects, as well as 18-27mg of iron to prevent iron-deficiency anaemia, linked to premature birth and low birth weight babies.
But prenatal supplements do not contain enough calcium—1,000mg a day are needed to protect a pregnant woman’s bones and build strong bones and teeth in her baby. Be sure to eat enough calcium-rich foods, such as milk, cheese and leafy greens, or take a calcium supplement daily.
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