Healthy Eating During Pregnancy

Healthy eating during pregnancy is very similar to healthy eating when not pregnant:  you should be eating a well balanced diet from many different food groups.  Remember the general guideline to eat yourself a rainbow, getting many different colored foods into every meal.  

When pregnant, do not believe the myth that you are eating for two.  In today’s society, most women are well nourished at the start of their pregnancies. A bit extra—300 calories a day—is all that is needed. Some examples of 300 calorie snacks are a bowl of cereal with milk, an egg with toast, or a banana with a large glass of milk.

Keeping your intake at a reasonable amount pays huge dividends at the end. A normal weight gain pre-delivery makes a vaginal delivery more likely, makes it easier to move at the end of pregnancy, and in general makes one feel better.  A normal weight woman should gain about 25-35 pounds total, an overweight woman should gain 15-25 pounds, an obese woman should gain 15 pounds, and a woman carrying twins should gain about 35-45 pounds.

Many women ask: what should I do if I feel so nauseated that I cannot eat?  Thankfully this symptom usually goes away by about 14 weeks of pregnancy.  If you have had a normal diet and normal body weight prior to pregnancy, you do not have to be concerned.  Your stored body nutrients will supply the developing fetus with everything it needs.  It is helpful if you can continue to take prenatal vitamins. If you simply cannot tolerate prenatal vitamins, I tell patients to temporarily switch to a children’s chewable vitamin until they are able to tolerate the prenatal vitamins.

Special Considerations

Folic Acid is a critical nutrient that helps prevent neural tube defects (malformations of the spinal cord).  Ideally a woman will begin taking folic acid supplements at least one month before she conceives.  The daily dose is 0.4 milligrams a day.  It is hard to get enough of this vitamin in one’s diet, so a supplement is strongly recommended.  A woman who has had a child with a skull or spine defect should take even more folic acid:  4 milligrams daily.

Vegetarian diets also require some extra attention.  A vegetarian diet is safe to continue in pregnancy.  Special attention needs to be paid to protein, vitamin B12 and vitamin D.  In general, if one’s vegetarian diet includes fish, poultry, eggs and dairy, the other needs will be met.  If one is strictly vegan, I suggest she add a calcium supplement, a prenatal vitamin, and significant soy or hemp intake to up her protein intake.

Calcium is a critical mineral because it will build the new baby’s skeleton.  The developing fetus always wins the calcium battle. If you’re not getting enough calcium for both you and the fetus, you will lose calcium from your own skeleton, which could predispose you to osteoporosis in the future.  Lowfat milk, yogurt, and other dairy products are great sources of calcium.  Three servings a day are the minimum recommended dose.  Keep in mind that ice cream does not count (sadly) because it has too many calories for the amount of calcium delivered.  If a woman cannot tolerate lactose, the sugar in milk, I suggest she try lactose-free milk or add a calcium supplement to her diet.   

Nutritional Dangers

There are definitely some foods and drinks to avoid during pregnancy.  Most women know to avoid alcoholic beverages.  Alcohol can result in fetal alcohol syndrome, which is a combination of malformations and mental retardation.  I am often asked how much alcohol counts.  For example, is a glass of wine a day really going to be a problem?  The actual problem is that alcohol is metabolized very differently among individuals. Therefore the absolute dose given to the fetus is unknown.  The bottom line:  do not drink alcohol during pregnancy. The same goes for any other substance use such as cigarettes, marijuana, cocaine, heroin, crystal meth, etc.

Fish intake is always a confusing question.  The media is full of articles on both how great fish is for your health, and how much toxic mercury fish can contain.  In general, fish is an important part of a healthy diet.  Omega 3 fatty acids, which are common in fatty fish such as salmon, may play an important role in the development of the fetal brain.  In contrast, mercury is a poison that can cause mental retardation.  Therefore, the guidelines state that women who are pregnant, may become pregnant, or are nursing should not eat high mercury fish such as shark, swordfish, king mackerel or tilefish.  Women may eat up to twelve ounces of other fish types a week (always cooked, of course). 

Why does it matter if fish is cooked?  Listeriosis is the answer.  Listeriosis is an illness caused by bacteria found in unpasteurized milk, soft cheeses, deli meat, raw veggies (uncleaned) and raw fish.  The infection can result in miscarriage or stillbirth.  Pregnant women are advised to avoid:

o       Unpasteurized milk or soft cheeses

o       Raw or undercooked meat or poultry

o       Processed meats, such as hot dogs or deli meats, unless they are reheated until steaming hot.

In Summary

Eating a well balanced diet during pregnancy is a great way to get you and your family off to a great nutritional start.  As always, questions that you have should be discussed with your physician or midwife.  Another great source of information is the web site of the American College of Obstetricians and Gynecologists (www.ACOG.org).  The patient education tab is full of useful information.  Remember, it is never too late to begin a healthy lifestyle.

Are you pregnant and confused about a particular area of nutrition? Let me know and I’ll try to answer your questions.    

Kristen Eckler, M.D., is an Instructor of Obstetrics, Gynecology, and Reproductive Biology at Harvard Medical School, and an Assistant Professor of Obstetrics, Gynecology, and Reproductive Biology at Massachusetts General Hospital.

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