What's the most reliable method of predicting a baby's gender? Well, ultrasounds are usually pretty on-point.

©iStockphoto.com/monkeybusinessimages

Carrying High or Low: Old Wives' Tale or Not

Carrying high? It's a girl.

Carrying low? It's a boy.

On its face, the statement doesn't sound all that unscientific -- or least not as unscientific as the old swing a ring over a woman's pregnant belly trick. After all, it at least seems possible that the position or shape of the uterus could reflect something about the baby growing inside. And it's not just "high or low." There's also the belief that "carrying wide" indicates a girl, and "carrying narrow" means it's a boy.

First, what do these things even mean?

High and low are about the position of the uterus. "Carrying high" means the most protruding part of a pregnant belly (the "bump") is high on a woman's abdomen, sometimes right up under her breasts. If a woman is "carrying low," the giant mound of baby is closer to the pelvis. "Wide" or "narrow" refers to the shape of the uterus -- entirely out front (narrow) or also to the sides (wide).

So if a woman is carrying both high and wide, that means it's a girl, right?

It absolutely does -- 50 percent of the time.

It turns out, the high/low method is just as accurate as pouring Drano into a cup of the woman's urine. Which is to say, not at all [source: KidsHealth]. Lots of people would swear by these methods; but when there's always a 50/50 chance of being right, you're going to find lots of correct predictions.

While it's unclear why exactly the "old wives" believe the baby's gender determines the position of the bump, it is perfectly clear what actually determines that position: muscles and body type. Basically, the tighter a woman's abdominal muscles (either due to age or fitness level), the higher the bump rides. An older woman or one who's had her abdominal muscles loosened by prior pregnancies will usually carry lower.

And shape is related to body type -- specifically, torso length. A short torso results in less room for the uterus to grow upward, so it ends up getting wider. A woman with a longer torso has more room between the pelvis and the rib cage, so the uterus can stay narrower as it grows.

The baby's position matters, too. A baby who's stretching sideways makes a woman carry wider. And as the baby "drops" late in the pregnancy, a high bump will get lower.

Now, while old wives' tales are not actually very useful in deciding whether to stock up on pink or blue, that doesn't mean they're not fun to try. Some of them are downright wacky.