Pregnancy Myths, Dos, and Don'ts

Medically Reviewed by Jennifer Robinson, MD on August 22, 2021
6 min read

Your pregnancy has attracted plenty of well-meaning advice on what to avoid to maintain your health. So, what to believe (other than what your doctor tells you)?

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. The U.S. Department of Agriculture cautions that you not eat unpasteurized soft cheeses (and other unpasteurized dairy products), hotdogs, or lunch meat unless they have been properly 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, unpasteurized, or locally-made "natural" 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.

The FDA has said most common sweeteners, including those found in diet sodas, are safe to use in moderation during pregnancy. They include aspartame (NutraSweet and Equal), sucralose (Splenda), saccharin (Sweet'N Low), acesulfame potassium, neotame, and advantame. Saccharin is the exception. Avoid it during pregnancy.

Most studies show no adverse effects from three or four cups of coffee per day during pregnancy. Still, some doctors and midwives are cautious and point to studies linking java to attention deficit hyperactivity disorder (ADHD) 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 says. "Pregnancy is hard enough on you."

Many herbal teas are safe during pregnancy, but you should be cautious. Large amounts of some herbs such as peppermint and red raspberry leaf are thought to cause contractions and increase the risk of preterm labor. While pregnant, 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.

The 2015-2020 Dietary Guidelines for Americans advise pregnant, nursing, or even women considering having children, to eat 2-3 servings (8-12 ounces) of certain varieties of seafood each week in order to protect developing babies from high levels of potentially brain-damaging mercury.

Here are drafted recommendations and guidelines that government officials say will help pregnant women reduce their exposure to mercury:

  • Do not eat shark, swordfish, king mackerel, bigeye tuna, orange roughy, or golden or white snapper (tilefish) from the Gulf of Mexico, because they often contain high levels of mercury.
  • Eat 8-12 ounces (2-3 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, limit your consumption of albacore tuna to 6 ounces (1 average meal) per week.
  • When eating fish you or others have caught from streams, rivers, and lakes, pay attention to fish advisories on those waterbodies. If there are no warnings, limit eating such fish to 6 ounces a week and 1-3 ounces for young children.
  • When adding more fish to your diet, be sure to stay within your calorie needs.
    Fish sticks and fast-food sandwiches are commonly made from fish that are low in mercury.

Gobble it up, Dolan says. Spinach has lots of folic acid, which 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.

Despite all the dirty looks from relatives, some pregnant women still have a glass of wine now and then. Because no safe level of alcohol consumption has been established for pregnant women, Dolan recommends avoiding it altogether.

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.

Your nails grow faster when you're pregnant, so perhaps it's time to let nature take its course. Besides, nail salons often smell strongly of chemicals, and if it smells strong, it probably isn't good for you or your baby.

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 unborn baby's brain development at risk.

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.

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.

Lying 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, a major deep abdominal vein, cautions Dolan.

It's probably best not to overheat when pregnant, and that means avoiding hot tubs and amping up your workouts.

Do not start an extensive exercise program while pregnant if you have never exercised before. Walking is a good choice.

Cats can carry a disease called toxoplasmosis that can harm a fetus and lead to birth defects. Your vet can test for it, but better still, follow some simple advice from the CDC when you're pregnant. Have someone else change the box -- and frequently -- because it is only after 1 to 5 days in the litter box that toxoplasmosis becomes infectious.

You can also try to keep your cat indoors and avoid giving it raw meat to prevent it from being exposed to Toxoplasma infection. If you garden, wear gloves and wash hands well. The soil can contain organisms from cat feces.

No big deal, Dolan says.

The first trimester of pregnancy may not be the best time to exercise your green thumb.

A recent study suggested that common weed-killers 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.

A majority of pregnant women experience indigestion as a result of hormonal changes and pressure from a growing uterus. So, it may be best to avoid foods that can trigger heartburn. They won't hurt the baby, but they'll make you mighty uncomfortable. Smoking is also a cause of heartburn.

Some people recommend a dose of castor oil to kick-start labor, but it tastes terrible and violent diarrhea might spoil the mood. It is not recommended.

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

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

The guessing game has been trumped by the ultrasound, but a slew of myths about a baby's gender persists: carry the baby low and it's a boy, carry wide and it's a girl, nose getting bigger and it's a girl, etc. Each has a 50% chance of being true.