When you're pregnant, all the "Congrats!" come hand in hand with a stream of cautionary tales and bizarre factoids. What's true and what's not:
True or false? If you're stressed out during pregnancy, it'll hurt your baby.
False. There's no medical connection between everyday worries -- too many tasks to juggle, say, or a disagreement with your mate -- and giving birth to an unhealthy baby. One study even suggests that cortisol, a hormone released when you're stressed, may actually help your child's brain development. So relax: It's normal to have some anxiety during pregnancy, and you don't have to feel guilty about it.
True or false? If you have heartburn, your newborn will have a full head of hair.
True. Researchers at Johns Hopkins University set out to disprove this but were surprised by evidence supporting it. They found that 82 percent of women with moderate to severe heartburn delivered hairy babies; most women with little or no heartburn ended up with baldies. Makes sense, since the hormones responsible for heartburn also trigger fetal hair growth.
True or false? Having sex late in pregnancy can trigger labor.
True. Women who have sex after 36 weeks are more likely to deliver within two to five days than those who don't, found the largest study to date. Doctors think prostaglandin, a substance in semen, combined with female hormones released during sex can jumpstart contractions. While not all experts agree there's a link, one thing is certain: If you're near your due date, it can't hurt to try.
True or false? If you eat peanuts when you're expecting, your child will become allergic to them.
False -- usually. The PB&J you're craving probably won't cause any harm. In fact, the protein and folates in peanuts are especially important during pregnancy. The caveat: If you or the father have any kind of allergy, or even asthma, exposing your baby-to-be to peanuts may up her risk of developing an allergy to them, so do skip 'em -- for now.