Nutrition and weight gain during pregnancy

A balanced, nutritious diet during pregnancy is important to maintain your health and nourish your fetus. Be sure to increase your daily caloric intake by 300 calories after you become pregnant.

The average woman needs 2,200 calories a day and 2,500 when she is pregnant. If she is carrying twins, her need increases to 3,500 calories, and for triplets or more, she needs 4,500 calories.¹ Talk to your health professional or a dietitian about your daily calorie needs, because your needs depend on your height, weight, and activity level.

Your health professional may give you a nutrition plan to follow throughout pregnancy and while breast-feeding. You may also receive a prescription for a vitamin and mineral supplement or a list of recommended nonprescription supplements.

Check out the federal Women, Infants, and Children (WIC) nutritional program for helpful information (http://www.fns.usda.gov/wic/). If your resources are limited, you may qualify for WIC financial assistance for basic healthy foods during and after your pregnancy.

Folic acid

Folic acid is a B vitamin. Taking folic acid before and during early pregnancy reduces the chance of having a baby with a neural tube defect or other birth defects.

• Women of childbearing age should get 0.4mg of folic acid from fortified food, supplements, or a mix of food plus supplements. This amount is found in most once-a-day multivitamins.²
• Women who are pregnant with twins or more should take 1mg of folic acid daily. Folic acid is available in this strength by prescription only.³
• Women who have a family history of neural tube defects, who have had a baby with a neural tube defect, or who are on medications for seizures should take additional folic acid: A daily dosage of 4mg of folic acid is recommended. Do not try to reach this amount of folic acid by taking more multivitamins, because you could get too much of the other substances that are in the multivitamin.²

Iron

You will need twice as much iron in your second and third trimesters as you did before pregnancy. This extra iron supports the extra blood in your system and helps with the growth of the placenta and the fetus. Wait until your second trimester to start taking iron. Your iron requirements are slight during the first trimester of pregnancy, and taking iron supplements in the first trimester may aggravate morning sickness.

After the first trimester, take a daily supplement containing 30mg of iron (most prenatal vitamins include iron). Women with multiple pregnancy are advised to take 60mg to 100mg of iron daily.³ Iron supplements can cause an upset stomach and constipation. Taking your iron at bedtime may decrease the chance of stomach upset. Your body absorbs iron best in small amounts when you eat it with vitamin C, so you may want to take your iron throughout the day.

Calcium

Calcium is necessary for the development of the fetus's skeleton. You can get enough calcium in your diet by eating or drinking 4 servings from the dairy (milk) group each day. Good sources of calcium from nonmilk sources include:

• Greens (such as mustard and turnip greens), bok choy, kale, and watercress.
• Broccoli and cauliflower.
• Tofu that is "calcium-set."
• Corn tortillas made with lime.
• Calcium-fortified orange juice.

Weight gain during pregnancy

The recommended weight gain for a woman of normal weight is 25lb to 35lb. A gain of 30lb usually consists of the following:

• The baby weighs 7.5lb.
• The placenta weighs 1.5lb.
• The amniotic fluid weighs 2lb.
• The uterus weighs 2lb.
• Breast tissue weighs 2lb.
• Excess blood and fluids weigh 8lb.
• Fat weighs 7lb.

You can expect to gain more if you are carrying twins.

If you are overweight, your ideal goal is less than the average weight gain, 15lb to 25lb. If you are underweight, it is best to gain 28lb to 40lb.

Ideally, you will gain weight slowly over the entire pregnancy:

• Up to 4lb during the first trimester
• 1lb a week during the second and third trimesters

If you stop gaining weight for more than 2 weeks, or if you gain weight faster than these recommendations, consult your health professional.

Citations

1. Newman RB (2003). Multiple gestation. In JR Scott et al., eds., Danforth's Obstetrics and Gynecology, 9th ed., pp. 225–245. Philadelphia: Lippincott Williams and Wilkins.

2. Committee on Genetics, American Academy of Pediatrics (1999). Folic acid for the prevention of neural tube defects. Pediatrics, 104(20): 325–327.

3. Cunningham FG, et al. (2005). Multifetal gestation. In Williams Obstetrics, 22nd ed., pp. 911–948. New York: McGraw-Hill.