Myths, Dos, and Don'ts of Pregnancy

Last Editorial Review: 5/26/2005

What's safe to eat during pregnancy? Can hair dye hurt the fetus? And what's this about not changing the litterbox?

By Star Lawrence
WebMD Feature

Reviewed By Charlotte E. Grayson, MD

The national nannies and the old wives have formed an alliance to pepper the pregnant woman with directives on everything from alfalfa sprouts to Zithromycin. So what's the skinny (remember, however,  what your doctor says goes)?

Food and Drink

The CDC says listeriosis, a food-borne illness with mild flu-like symptoms that can be overlooked, can result in premature delivery, miscarriage, severe illness, or death of the baby. Heidi Murkoff, author of What to Expect When You're Expecting, concurs with the U.S. Department of Agriculture, which cautions that you not eat unpasteurized soft cheeses (and other unpasteurized dairy products), hotdogs, or lunch meat unless cooked.

Cheeses made in the U.S. must be made from pasteurized milk (this process kills the listeria organism), so they are fairly safe. Imported soft cheeses are potentially problematic. These may include Brie, Camembert, feta, goat, Montrachet, Neufchatel, and queso fresco. Listeria may also be found in unpasteurized semi-soft cheeses (slightly more solid cheeses that do not grate easily and are often coated with wax to preserve moisture and extend shelf life). Semi-soft cheeses include Asiago, blue, brick, Gorgonzola, Havarti, Muenster, and Roquefort.

Cheddar, mozzarella, cream cheese, and cottage cheese are fine. "Stay away from those yummy roadside ciders, too," Murkoff advises. "They're not pasteurized."

Diet soda
Minimal harmful effects have been shown from the use of the artificial sweetener aspartame in pregnancy, according to Siobhan M. Dolan, MD, assistant professor of obstetrics and gynecology at the Albert Einstein College of Medicine in the Bronx, N.Y. "Like everything else, moderation is best." A daily diet pop or aspartame-sweetened yogurt is probably harmless.

Most studies show no adverse effects from three or four cups of coffee. Still, some doctors and midwives are cautious and point to studies linking java to attention deficit hyperactivity disorder and migraines. There are some data that suggest that large amounts of caffeine lead to low-birth-weight babies.

However, if you choose to drink coffee, moderation is key. "Sometimes it's harder on you to quit entirely," Dolan admits. "Pregnancy is hard enough on you."

Herbal tea
Herbal teas can be safe during pregnancy, but you should be cautious. Be sure to steer clear of teas that have unfamiliar ingredients; instead, look for those teas that are made from ingredients that are a part of your normal diet (like orange extract). Remember that "natural" doesn't always mean "safe." If you are unsure, talk to your doctor.

According to Murkoff, raw fish, which can contain parasites, is probably not advisable when cravings strike.

In March 2004, the FDA and EPA issued joint guidelines regarding eating fish during pregnancy. They advise women who are pregnant, nursing, or even considering having children to eat no more than two servings of fish each week in order to protect developing babies from high levels of potentially brain-damaging mercury.

By following their recommendations and guidelines, government officials say that women will receive the benefits of eating fish and shellfish and be confident that they have reduced their exposure to the harmful effects of mercury.

  • Do not eat shark, swordfish, king mackerel, or golden or white snapper (tilefish) because they contain high levels of mercury.
  • Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury. Five of the most commonly eaten fish and shellfish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.
  • Another commonly eaten fish, albacore ("white") tuna, has more mercury than canned light tuna. So when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (1 average meal) of albacore tuna per week, they say.
  • Because tuna steak generally contains higher levels of mercury than canned light tuna, when choosing your 2 meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of tuna steak per week.
  • Fish sticks and fast-food sandwiches are commonly made from fish that are low in mercury.

Gobble it up, Dolan says. Folic acid is one substance you want when you're pregnant, especially before conceiving and during the first trimester. The recommended dose is 400 micrograms a day. "Folic acid reduces the incidence of neural tube defects by 70%," she says. "It's one thing that really has a good effect."

In addition, spinach is loaded with iron, a mineral essential for health.

Alcohol and Tobacco
Despite all the dirty looks from relatives, some pregnant women still have a glass of wine now and then. No safe level of alcohol consumption has been established -- but since there is no safe level, you and your doctor need to decide. Dolan recommends excluding all alcohol at least during the first trimester when so much of the baby's nervous system is being formed.

Of course, that familiar cigarette is out altogether! In addition to nicotine, cigarettes contain thousands of additives that leap across the placenta into your baby's system. At the very least, prematurity and low birth weight can result from smoking, Dolan says.

Eating for Two
Before you start eating for two, Murkoff says, "remember that one of the two of you is about the size of a grain of rice at first. You only need about 300 extra calories a day when you're pregnant."

Beauty Treatments

Artificial Nails
Your nails grow faster when you're pregnant, so you can probably make do with "home-growns," Murkoff says. Nail salons often smell strongly of chemicals, and if it smells strong, it probably isn't good for you or your baby, she says.


The first sign of pregnancy is most often: See Answer

At least one study has also shown that pregnant women who work in nail salons, dry cleaning establishments, medical laboratories, and manufacturing plants who work with smelly chemical solvents may be putting their fetus' brain development at risk.

Bikini wax
Aren't you the glam mom-to-be! Pregnant women sometimes do find hair in the most unwanted places, not just bikini country. Wax is preferable to chemical depilatories.

Hair dye and perms
There are no data supporting harmful effects of hair dye, either, according to Dolan. "Very little dye reaches your scalp, anyway." The smells, however, can gross out a pregnant woman's overly sensitive sniffer.

Awake and Asleep

Left side for sleeping
Murkoff says propping everything into a comfy position on your left side after the fourth month minimizes pressure on your uterus and intestines and speeds up nutrients to the baby. If you wake up in a different position, such as your back, flop over and start again. Lying on your back puts too much pressure on the vena cava, cautions Dolan.

Exercise and hot tubs
It's probably best not to overheat when pregnant (although the studies were done on women with fevers, who probably had other things wrong with them). "If you never exercised," Dolan cautions, "you should not start when pregnant. If you do exercise, this is not the time to increase your workout."

Changing the litter box
Cats can carry a disease called toxoplasmosis. Your vet can test for it, or dad can change the box. Gloves are a good idea in any event.

Using the computer
No big deal, Dolan says.

Lawn work
The first trimester of pregnancy may not be the best time to get in touch with your inner groundskeeper.

A recent study suggested that common weedkillers may cause developmental problems. Researchers found exposure to chemically treated golf courses and lawns before the recommended waiting period is over could harm the developing embryo. The EPA is currently evaluating these findings.

Bringing on Labor

Castor oil
Some people advise a dose of the old-time remedy to kick-start labor, but this stuff tastes terrible, and a violent diarrhea might spoil the mood.

It passes the time and is OK if your doctor advises it. But there is no evidence it will bring on labor.

Having sex
Prostaglandins, substances in semen, plus the contractions of sex, can hasten labor in some cases. Some doctors even prescribe it.

Spicy foods
Feel like a nice case of gastritis?

Predicting the sex
The old wives have been aced by ultrasound these days, but a slew of myths persist: carry low and it's a boy, carry wide and it's a girl, nose getting bigger and it's a girl, Drano in the toilet, you've heard them all. Each of these, Murkoff says, has a 50% chance of being true.

Originally published Aug. 6, 2002.
Medically updated Feb. 7, 2005.

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