10 Myths About Pregnancy, Debunked

Could everything you know about pregnancy be wrong? Get your facts straight Could everything you know about pregnancy be wrong? Get your facts straight Think you've got the whole birds-and-bees thing figured out? Turns out, much of what we know about baby-making is based on old wives' tales instead of scientific research, according to the just-released book, Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong--and What You Really Need to Know. Prepare to have your mind blown.

Myth: Pregnancy Lasts Nine Months
Truth: In reality, the length of your pregnancy can vary by as much as five weeks, according to a 2013 study published in the journal Human Reproduction. When you deliver ultimately depends on your age, your weight, how much you weighed at birth, and a slew of other factors.

Myth: Sex while you're pregnant can hurt the baby.
Truth: In almost all cases, sex shouldn't affect your little one, says Shari Brasner, M.D. assistant clinical professor of obstetrics, gynecology, and reproductive science at Mount Sinai School of Medicine in New York City and a member of the Women's Health expert advisory board. There are some exceptions, though: If your placenta is positioned between your cervix and vagina or if you're at a high risk for a preterm birth, ask your doctor before doing the deed.

PLUS: 5 More Myths About Female Desire

Myth: The baby's sex affects the positioning of your baby bump.

Truth: "The baby's sex has absolutely nothing to do with the way a woman appears," says Brasner. So sorry--you can't tell the baby's gender just by looking at mom.

Myth: If you have an STD, your baby will, too.
Actually, it depends on the STD you have, says Brasner. That's because some STIs infect the blood and can pass through the placenta, while others only pose a threat by direct contact. This second type can be passed along during a vaginal delivery, so your doctor might recommend a C-section to prevent infection.

Myth: You can't run while you're pregnant.
"A lot of what a woman can do during pregnancy depends on what she was able to do before pregnancy," says Brasner. (And no, you don't have to worry about the baby tumbling out while you're on the treadmill.) You can keep doing what you're doing, or try a cardio workout plan specially designed for your first, second, or third trimester.

Myth: You can't have a natural birth after you've had a C-section.
While evidence suggests that having a vaginal birth after cesarean (VBAC) is slightly riskier than a repeat C-section, a VBAC is a reasonable option for many women, says Brasner. Just discuss the pros and cons with your doctor before you hit the delivery room.

PLUS: What You Don't Know About C-Sections

Myth: You lose your baby weight during the delivery.
Buzz kill alert: Women only lose between 10 to 15 pounds--including the baby and some water weight--when they give birth, although most women gain between 25 and 35 pounds throughout the pregnancy. It can take a year or more to lose the rest. (But on the bright side, breastfeeding can speed things along.)

Myth: You're eating for two.
Growing a baby inside you doesn't burn as many calories as you might think. If you already eat a well-balanced diet, adding a snack or two a day (about 300 extra calories) is all you need.

Myth: Every woman can breastfeed if she wants to.
Certain breast surgeries can make breastfeeding difficult, and some medications can make breastfeeding ill advised, says Brasner.

RELATED: Everything You Need to Know About Breastfeeding

Myth: Certain foods-and sex-can bring on labor.
While getting busy and doubling up on hot sauce won't hurt the baby, there's limited evidence indicating that any activities or foods can reliably stimulate labor, says Brasner.

By Elizabeth Narins, Women's Health

More from Women's Health:

7 Pains You Should Never Ignore

The 7 Lies We Tell Our Doctors

10 Self-Checks Every Woman Should Do

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