January 20, 2019
Pregnant Woman Holding Teddy Bear

Can You Guess a Baby's Sex Before Birth?

by Gina Shaw  

Myth: You can tell the sex of a baby by how a woman carries during pregnancy.

Fact: If you’ve ever been pregnant, it’s almost a certainty that at some point your neighbor, or your mother-in-law, or the checkout clerk at the grocery store declared, “You’re carrying low, it’s a boy!” (Sometimes the claim is the other way around: Carry low, it’s a girl.) Or: “You’ve gained weight all over, you must be having a girl!” (Uh, thanks?)

The belief that the gender of an unborn baby is revealed by the way the mother carries during pregnancy is just one of a seemingly endless set of old wives’ tales. There’s also this one: “If you’re craving sweets, it’s a girl; salty food, it’s a boy.” And this one: If you have that “pregnancy glow,” you’ll have a boy, but if you’re looking tired and run-down, that baby girl is “stealing your good looks.” (Way to make a pregnant mom feel great!)

In a study dating back to 1999, researchers at Johns Hopkins tested the “how you carry” gender-predictor notion in 104 pregnant women who did not know the sex of their unborn baby, but filled out a questionnaire about what they thought it would be, based on whatever method, hunch, or “idiosyncratic explanation” they had. In addition, the women reported the shape of their abdomen and the frequency and severity of morning sickness.

Turns out that the way the women carried (or other approaches they used to predict their baby's gender) had no relationship to whether or not they were having a boy a girl. Nor was morning sickness a predictor —though other research suggests that women who have severe nausea early in pregnancy may be slightly more likely to have girls. Overall, the women were correct in their predictions 55 percent of the time (within the range of chance).

But interestingly, women who had more than a high school education predicted the sex of their baby more accurately than chance, getting it right 71 percent of the time. Women with less education were right only 43 percent of the time (not worse than chance). And among those with higher education, women whose gender forecasts were based on “psychological criteria”—dreams or feelings—were more likely to be correct compared to women with less education. According to the researchers, “it is always possible that this was a spurious finding. It is equally likely that there is simply much about the maternal-fetal connection that we do not know.”

In actuality, how a pregnant woman carries may depend on several factors, such as the strength of her abdominal muscles, the length of her torso, and the position of the baby—and all babies will eventually drop as the due date gets closer.

If you want to be more certain about the sex of your baby, you can usually tell at the ultrasound that most ob-gyns do at around 18 to 20 weeks of pregnancy (scans done earlier tend to be unreliable). But even then, your baby might be positioned in a way that you can’t be certain whether those are boy parts or girl parts.Tests done to screen for genetic abnormalities may also determine gender very accurately. These include the noninvasive Prenatal Testing (NIPT, done as early as 10 weeks of pregnancy) and the more-invasive and thus riskier procedures ofamniocentesis (done between 14 and 20 weeks) and chorionic villus sampling (done between 10 and 13 weeks).