Do They Work? Here’s The Truth About 7 Gender Prediction Tests

Can you eat lots of bananas to give birth to a boy? What does it mean if you're "carrying low"? Can Drano tell you the sex of your baby? We explore.

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Pseudoscience, folklore, and old wives’ tales abound regarding how to predict or control important life events.

Guess how many children you’ll have by swinging a necklace in front of your face! Make someone propose to you by eating a hard-boiled egg filled with salt! Predict whether you’ll live in a mansion, an apartment, a shack, or a house by scribbling spirals on your paper tablecloth at a steakhouse chain with peanut shells on the floor!

You know, typical ancient wisdom.

Some of the most popular rituals are to test or influence babies’ genders, and boy are there some weird ideas about that. But is there proof that any of these is effective? Read on to learn eight ways to predict or control your baby’s gender, and whether they stand a scientific chance.

Peeing Into Stuff

Peeing into stuff, theory one: If a pregnant woman pees into Drano, the color will determine whether she’s having a boy or a girl. (There are multiple combinations of which colors supposedly correlate to which sex.)

Peeing into stuff, theory two: If a pregnant woman pees into baking soda and it fizzes like soda it means the baby’s a boy, and if it’s flat it means the baby’s a girl.

Peeing into stuff, theory three: If a pregnant woman pees into the water drained off of boiled, chopped-up red cabbage, the color determines an unborn baby’s sex. (Red or pink means boy; violet means girl.)

Does it work? We’ll quote here the fact-checking site Snopes regarding the Drano Test, and we feel confident it applies to the others as well: “Mixing Drano with urine will not predict the sex of an unborn child any better than will hanging a dead chicken from the flagpole and watching to see which way the wind riffles it.”

How It Gets Done

Some believe that the way you conceive can determine the baby’s sex, and this notion goes back pretty far.

The ancient Greeks thought a man who was lying on his right side during the deed would increase their chances of having a male baby. Similarly, it was believed that if a pregnant woman’s right side of her chest swelled, it meant she was carrying a boy. And so on and so forth with the “right means boy” and “left means girl” anatomical preoccupations.

(This makes sense because the Greeks attributed symbolic significance to right and left, with right being superior; they weren’t really known for their high opinions of women.)

More recent iterations of this idea, according to health writer Jeremy Laurance in The Independent, are based on the theory that “male” sperm die sooner and are “small and fragile but quick” and “female” sperm live longer and are “larger and tougher but slow.”

So, conceiving in certain positions will bring you a girl because because the sperm will be farther from the cervix, meaning that it will have to tough it out through acidic secretions to get to the womb. On the other hand, baby making in other positions will bring you a boy because the agile male sperm will be more adept at swimming against gravity.

The theory was apparently popularized by Dr. Landrum B. Shettles in the 1960s, who published his findings in medical journals and in the book How to Choose the Sex of Your Baby .

Does it work? Nah. As Drs. Yvonne Bohn, Allison Hill, and Alane Park, authors of The Mommy Docs’ Ultimate Guide to Pregnancy and Birth tell NPR, “There is no [position] that will guarantee a desired gender. The gender of the baby is determined by […] either an X chromosome, producing a girl — or a Y chromosome, producing a boy.”

Anyway, cue the unsettling opening credits of Look Who’s Talking that will remain seared into our memory forever.

The Mother’s Diet

Plenty of theories make claims about a mother’s diet and the gender of baby she will produce or is carrying. For example, a woman who craves sweets is having a boy and a woman who craves sour foods is having a girl. Or a woman who eats a lot of spicy foods is carrying a boy.

Laurance in The Independent writes about the Victorians’ suggestion “that would-be parents who wanted boys should go on a strict diet because the male was the ‘starved sex.'” And today there are websites devoted to altering your diet to influence your child’s gender.

Does it work? Surprisingly, it can—but not in the ways we’ve imagined. According to research from the University of Oxford and the University of Exeter published in 2008, women who don’t skip breakfast and who consume more calories around the time of conception, particularly bananas and breakfast cereal, are more likely to have boys.

This may be because, as Tara Parker-Pope points out in The New York Times, “male embryos are less viable in women who regularly limit food intake, such as skipping breakfast, which is known to depress glucose levels,” and “low glucose level may be interpreted by the body as indicating poor environmental conditions and low food availability.”

Position Of The Baby Bump

You know the deal! If you’re “carrying low” you’re having a boy, and if you’re “carrying high” you’re having a girl. Or is it the other way around?

Many swear that if a woman carries her baby high in the uterus and her stomach has a round appearance, the chances are excellent she is expecting a girl, Snopes reports. “Likewise, a boy is carried low and relatively more sideways. However, many swear by the exact opposite and believe boys are always carried high. Go figure.”

Does it work? Nope. Professor Steve Robson, Vice President of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, tells The Huffington Post:

“It’s clear to say that a child’s genitals has nothing to do with how the woman’s body looks when she is pregnant. The way a woman carries a baby has more to do with the size of the baby — then the belly tends to pivot forward. If the baby is smaller, it is more likely to be lower in the pelvis. So a baby that is larger than average is more likely to be higher, a smaller baby will be lower. It has nothing to do with their genitals and everything to do with the way the baby is lying in the uterus.”

Numbers Games

Two popular ways to try and guess your baby’s gender involve crunching numbers. According to one method, using the Chinese Lunar Calendar, the baby’s sex is determined by the mother’s age at the time of conception and the month she conceived.

Another method is based on the Mayan (Maya?) system. It says that, if you take the age of the mother at the time of conception and the number representing the month of conception and both numbers are even, or if both numbers are odd, the baby is a girl; if one number is odd and the other is even, the baby is a boy.

Does it work? There’s a 50 percent chance. (Hint: there’s a 50 percent chance with all the others too, though.) As far as we know, no major scientific studies have evaluated the likelihood that either of these methods will predict the correct sex every time, but we’re going to go out on a limb and say that it’s not any more effective than peeing into Drano.

(That said, the whole using-your-fingers thing to determine multiples of nine absolutely blows our mind, so anything’s possible, right? Right?)

Weight Gain During Pregnancy

Some people claim that women who gain the least weight during pregnancy are more likely to have a girl.

Does it work? As a correlation, not a cause.

By our analysis (we aren’t scientists), this theory would seem to fall in line with the research out of the University of Oxford and the University of Exeter, suggesting that women who consume high-calorie diets around the time of conception are more likely to give birth to boys.

However, it doesn’t seem to take into consideration that eating more calories around the time of conception doesn’t mean they continued to eat more calories throughout the remainder of the pregnancy. (Besides, eating more calories doesn’t necessarily mean weight gain, since different women have different basal metabolic rates.)

Cosmopolitan reports:

In a massive new [2014] observational study published in PLOS ONE that accounts for more than 68 million births over 23 years, researchers found that women who gained the least weight during pregnancy were more likely to give birth to girls. Fifty-one percent of babies born to moms who gained less than 20 pounds during pregnancy ended up being girls. … Researchers still can’t entirely explain the relationship between your weight gain and the likelihood that you’ll give birth to a boy or girl. But they did find that mothers who gained low amounts of weight and miscarried were more likely to lose a male fetus than a female fetus.”

Morning Sickness Means Girl

Another well-worn idea is that women who have morning sickness are having a girl, and women who have no morning sickness are having a boy. One different version is that all moms-to-be have morning sickness, but moms-to-be carrying a girl have worse morning sickness than those carrying a boy.

And another says that only morning sickness during the first trimester is a determinant, with bad morning sickness indicating “girl” and no morning sickness indicating “boy.”

Does it work? Probably not…but maybe? “Morning sickness has nothing to do with gender. It just means some people are very prone to morning sickness the same way some people are prone to motion sickness,” Professor Robson tells The Huffington Post. “Also, morning sickness can be worse in one pregnancy than in another. But, again, it has no relationship to the gender of the baby and everything to do with hormones in pregnancy. Sometimes different hormone levels promote different levels of morning sickness.”

However, some studies have shown a connection between moms who suffer from a severe form of morning sickness called hyperemesis gravidarum and female births. Catherine, Duchess of Cambridge, reportedly suffered from the condition during both of pregnancies—her first child a boy, George, but her second is a girl, Charlotte.

Dangling Metal Things Over Pregnant Women

This is a fun one. If you’re a woman, you’ve likely been instructed at some point in your life to loop a ring through with a piece of your hair or a necklace chain, and then dangle the ring over your stomach to determine the number of children you will one day have and their genders (because of course you will have children).

Another version is specifically for women who are already with child. They’re instructed to use their wedding rings (because of course they are married) and, if the suspended ring rotates counterclockwise, the baby is a boy, while a clockwise rotation indicates that the baby’s a girl.

Then there’s this one, described in Snopes : “A pin or needle affixed to a piece of thread is dangled over the expectant woman’s wrist. If the pin swings back and forth, it’s a boy. If it twirls in circles, it’s a girl. Some suggest using a nail instead of a pin. Some say the pin or nail should dangle over the mother’s stomach instead of her wrist.”

Does it work? We can’t imagine a reason why it would…unless, like, magnetic fields? But yeah, common sense points to “clearly not.”

Anna Cherry
Anna Cherry is the staff writer for Multiply. She's lived in a few different places, written in more, and is now back in the state of her birth (Missouri).

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