12 crazy myths about pregnancy

Myth: Mom's belly reveals baby's gender

Baby lore says moms carry the baby wide if they're having a girl, or low for a boy. Not true. "The way you carry a baby has nothing to do with the sex of the baby," says Dr. Hill. Carrying is a function of mom's anatomy and how the developing baby positions himself/herself, she says.

Myth: Cocoa butter prevents stretch marks

No cream can prevent stretch marks. "The formation of stretch marks mostly has to do with a woman's collagen and how well her skin stretches," says Dr. Bohn. That's usually a matter of heredity.

Cocoa butter is a great moisturizer, but it isn't absorbed deeply enough to affect stretch mark formation. And slathering too much cocoa butter on the belly can lead to an itchy red rash, says Dr. Bohn.

Myth: Pregnant women must avoid cats

Exposure to cats won't harm a developing fetus, though cat feces can spread toxoplasmosis, a disease that can cause birth defects. "Pregnant women should not be cleaning up after their cats or emptying the litter box," Dr. Park cautions.

What about cleaning up after a dog? That's okay.

Myth: Moms can give colds to their developing babies

Few infections cross the placenta, so just because mom feels miserable from a cold doesn't mean her developing baby will. The most common infections in the first trimester are urinary and respiratory infections and stomach flu. These generally don't affect the fetus, but it's prudent to notify your doctor about them. "Urinary tract infections can lead to kidney infections, so they need to be treated with oral antibiotics," Dr. Hill says.

Myth: Pregnant women shouldn't wear high heels

Women can wear heels without hurting their developing baby - unless they make mommy trip and fall. "We're more concerned about the fact that as you get more and more pregnant, your center of gravity changes and you become less steady on your heels." Dr. Park says.

Myth: Exercise during pregnancy can strangle the baby

A mother's body motion has no effect on what's going on inside her uterus - one in four babies wrap the umbilical cord around some part of their body no matter what mom does.But that's not something most women need to worry about.

"If stretching or bending were actually dangerous, our hunter-gatherer ancestors would've been in big trouble," says Dr. Bohn.

Myth: Skipping breakfast starves the baby

Expectant moms can't harm the growing baby by missing one lunch or dinner. "You should listen to your body," Dr. Park says. "If you're really nauseous and have no appetite, it's okay to skip a meal."

Experiencing nausea and vomiting? Eat smaller meals throughout the day. And avoid triggers - thoughts or smells that make an expecting mom queasy. A doctor can also prescribe safe antinausea medication.

Myth: Pregnant women should avoid rock concerts

Though loud music might harm mom's hearing, it won't hurt her developing baby. The baby can hear noises outside the mother's body, but the amniotic fluid muffles the sound. "Imagine being underwater in a swimming pool, and you'll get the idea of what it's like for your baby, floating in its protective sac of amniotic fluid." Dr. Bohn says.

Myth: Pregnant women should avoid skin care products

Make-up, cleansers, moisturizers, self-tanners, and sunscreen can be safely used throughout pregnancy, Dr. Hill says. However, "Creams and cleansers containing salicylic acid can be used only if the concentration is less than two percent."

Myth: Pregnant women shouldn't dye their hair

Hair dyes are considered safe, as only a tiny amount of the dye is absorbed by the skin. The same is true for hair straighteners and perm rinses. Semipermanent dyes and highlights make better sense for pregnant women, as the ammonia in permanent dyes can trigger nausea.

Myth: Sex during pregnancy hurts the baby

There's no reason to stop having sex during pregnancy, "as long as you don't have unexplained vaginal bleeding, placenta previa, preterm labor, cervical insufficiency, or another extreme complication," Dr. Park says.

Myth: Pregnant women shouldn't fly

As long as the cabin is pressurized, flying will not harm your baby - at any stage of pregnancy. But most airlines limit travel in the last month because they fear pregnant women will go into labor on the airplane, according to Dr. Bohn.

If you do fly, Dr. Bohn says, "Walk up and down the aisles at regular intervals - at least every two hours - to help decrease the risk of blood clots in your legs, which can occur when anyone, pregnant or not, sits for too long."