Once you get that big fat positive pregnancy test, you may start scouring the web for the best gender predictor tests to find out: is it a boy or a girl?

According to a 2007 Gallup poll, Americans seem to be divided on whether they want to know the sex before the child’s birth. However, women under 34 years of age have a strong preference to know before the big day. (Learn more about the study here.)

Until fairly recently, the only way every expectant mama could learn the sex of her baby was on labor day itself. (After all, it wasn’t until the ’80s and ’90s when ultrasounds entered the picture, and Cell-Free DNA Screenings only became available in the 2000s.)

And, so, as you can imagine, women through the ages have turned to gender predictors. Some are based on pure myth. Others are old wives’ tales or superstitions, and others are actually based in science.

So, if you’re chomping at the bit before you learn your baby’s sex, this guide will show you which gender prediction methods work and which ones are just for fun.

11. Ring Gender Test

This gender predictor is a very old wives’ tale that involves dangling mama’s wedding ring from a string, chain, or hair strand and hanging it over her pregnant belly.

  • If the ring swings in a circle, expect a girl. 🎀
  • If the ring swings back and forth in a straight line, expect a boy. 🧢

Is it scientifically sound?

There is no scientific data or studies to back up this gender predictor.

The bottom line

We couldn’t find the actual origins of this gender predictor. Some women swear by it; in truth, it’s just a fun way to pass the time while you wait for a more solid answer about baby’s sex.

10. Food Cravings

Did you know that—according to folklore—you can predict your baby’s sex by your food cravings?

According to this philosophy…

  • If you crave citrus and sweets, you’re having a girl. 🎀
  • If you crave salty foods and meat, you’re having a boy. 🧢

Is it scientifically sound?

No, there are no studies that connect food cravings to baby’s sex. However, there was a study that showed women who were carrying a boy ate about 10% more food in general. Researchers believe it’s tied to testosterone signaling the mom’s brain. (Interesting to note: I craved sweets/carbs with my son and meat/salt with daughter 🙃.)

The bottom line

This “theory” likely originated from mothers comparing their own pregnancies. For instance, if a mama craved chocolate with her girl and salty snacks with her boy, she might assume that all chocolate-lovers may be carrying girls. However, this isn’t a reliable method, and here’s why…

Your pregnancy cravings are definitely telling you something—it’s just not whether your baby is a girl or a boy. Your cravings are much more likely to clue you to nutritional deficiencies. If you’re craving chocolate, for example, your body likely needs more magnesium or copper.

So, definitely, pay attention to your cravings—for nutritional reasons.

9. Carrying High or Low

Every pregnancy is unique—and so is every pregnant belly. Some mamas carry high, some carry low, and some bellies look different every day. According to the folklore, though, your belly can give you a clue if you’ve got a baby boy or a baby girl on board.

  • Carrying high? It’s a girl! 🎀
  • Carrying low? It’s a boy! 🧢

Is it scientifically sound?

Classify this as a “myth.” The shape of your pregnant belly is much more likely to be affected by:

  • the position of your baby
  • your body shape
  • the strength of your pelvic floor
  • the height of your baby

The bottom line

Belly shape and how you carry are not reliable indicators of the sex of your baby.

8. Baking Soda Gender Test

If you’ve ever created a vinegar-baking soda volcano, you’ll like this next test. This gender predictor is just as easy as as that experiment.

Pour two tablespoons of baking soda in a cup and add your urine.

  • If the mixture fizzes up like a soda, expect a boy. 🧢
  • If the mixture does not produce any reaction, expect a girl. 🎀

Is it scientifically sound?

Debates about the baking soda gender predictor’s accuracy are easily found online. Some moms swear by it, while others find consistently inaccurate results.

The thought process behind this gender predictor is that mama’s hormones may affect a mom’s urine. If she’s having a boy, her urine is more alkaline; a girl, her urine is more acidic. However, the science behind the fizz may have more to do with your diet and mineral reserves than your baby. Certain foods and supplements can alter the pH level of your urine, which explains why some women see the fizz and others don’t.

The bottom line

Try it for fun, but don’t put too much stock in this gender predictor.

7. Chinese Gender Predictor Test

The Chinese gender prediction chart has been around for a while, about 700 years to be precise. Legends say that eunuchs created the chart during the Qing dynasty to help the Imperial family create more male heirs. The palace guarded the chart for centuries, but eventually the chart made its way to Europe via an Austrian professor.

This chart, which is based on the lunar calendar, uses the mom’s age and the month of conception to predict gender.

Is it scientifically sound?

Many websites post new Chinese gender charts each year, but these yearly charts are not the same as the traditional Chinese gender chart created during the Qing dynasty. As a result, this gender predictor isn’t as authentic as many moms may believe. And regardless of which chart you use, the charts are not rooted in science.

The bottom line

Don’t put too much stock in this gender predictor. (Funny side note: I googled the chart, and it actually was right on for my two children, but then again, every test has a 50/50 chance!)

6. Intelligender

The Intelligender is an at-home kit that tests your urine to determine the gender of your baby. Although the kit tests your urine, it does not test the pH of the urine.

Accuracy

According to even the Intelligender website, this gender predictor is purely for fun, and no accuracy rate is listed on the product or their website. Haha! This just shows you how desperate some women are to find out the sex! Was Intelligender accurate for Mama Natural? You can find out here.

The bottom line

Save your money and skip the Intelligender test.

5. Baby Heart Rate

Using baby’s heart rate is one of the most popular gender predictors, but is it fact or fiction? According to this old wives’ tale, if the baby’s in-utero heart rate past the first trimester is:

  • Above 140 beats per minute (bpm), expect a girl. 🎀
  • If it’s under 140 bpm, expect a boy 🧢

Is it scientifically sound?

Researchers studied 966 first trimester ultrasounds and determined that the average male heart rate was 154.9 bpm, while the average female heart rate was 151.7 bpm. Study authors cited too small of a range to accurately distinguish between male and female heart rates.

The bottom line

Hearing baby’s heart rate for the first time can be a magical moment, but that little heart rate probably isn’t a good gender predictor.

4. Ramzi Theory

The Ramzi theory, developed by Dr. Saam Ramzi Ismail, is a gender prediction method that uses the placenta’s location as a determining factor for sex detection. According to Dr. Ismail, the baby’s sex can be detected by looking at the location of the forming placenta in an early (6-9 week) ultrasound.

  • If the placenta implanted on your left side, expect a girl. 🎀
  • If the placenta implanted on your right side, expect a boy. 🧢

Keep in mind that if you had an abdominal ultrasound, you will need to “flip” the image since it’s from the outside in.

How do you know where the placenta is forming?

  • Ask the tech during your scan (most foolproof way)
  • Locate the bright area around the sac

Accuracy

Dr. Ismail claims that his method can predict gender with 97% accuracy when using an ultrasound from weeks 6-9 of pregnancy.

Is it scientifically sound?

The jury is out on the Ramzi theory. Although Dr. Ismail published his research (on ObGyn.net), it was not published in any peer-reviewed journals. Additionally, there have been no further studies, making this seem an unlikely contender for the best gender predictor. Despite this, many moms post their six-week ultrasound in forums, hoping to get an answer if baby is a boy or girl.

Do know, too, that it’s not always easy for a technician to see the placenta in those early scans, especially if you’re pregnant with twins.

The bottom line?

Don’t paint your nursery or settle on a name… just yet.

3. Nub Theory

Like the Ramzi theory, the nub theory focuses on ultrasound images to predict gender. The difference is that this theory analyzes an ultrasound taken between 11 and 13 weeks, and focuses on the genital tubercle. The genital tubercle, aka the nub, refers to the baby’s genitals. In a boy, the nub will develop into the penis, while in a baby girl, the nub develops into the clitoris.

Until the 14th week of pregnancy, boy and girl babies both have the same size nubs. According to the theory, it’s the angle of the nub that predicts boy or girl.

  • If the nub is at a 10° angle or less, it’s a girl. 🎀
  • If the nub is at a 30° angle or greater, it’s a boy. 🧢

If the nub is between a 10° to 30° angle, it’s a toss up.

Accuracy

A 1999 study found that this gender predictor is accurate; however, the accuracy increases with gestational age:

  • 70.3% accuracy at 11 weeks,
  • 98.7% accuracy at 12 weeks,
  • and 100% accuracy at 13 weeks (!)

In a 2006 study, researchers studied 656 ultrasounds, of which 93% were able to be assessed and 7% were indeterminate. From the ultrasounds that were able to be assessed, researchers accurately predicted 99.6% of the males and 97.4% of the females.

Is it scientifically sound?

There is truth to this theory. Because nubs are the same size until the 14th week of pregnancy, the theory relies on the angle of it. A girl’s angle will be smaller, because the nub/clitoris will lay flatter, more in line with her spine. A boy’s angle will be greater, because the nub/penis will grow outwards, away from the spine.

Unlike the Ramzi theory, the nub theory has been studied and reports have been published in medical journals. In addition to studies listed above, research on this theory has been published in other medical journals such as Ultrasounds in Obstetrics and Gynecology.

The bottom line

This gender predictor works well if you have an ultrasound in sagittal view (which looks at you from a side view rather than straight on) and you measure the angle carefully. Once you have your scan, you can use a protractor to measure the angle of the nub.

2. 20-Week Ultrasound

Perhaps one of the most anticipated ultrasounds, the 20-week ultrasound (also known as the mid-pregnancy ultrasound or the anatomy scan) is the most commonly used tool to determine baby’s sex. Although the scan is meant to check baby’s growth and development, most parents call this “the gender reveal” ultrasound.

Accuracy

According to a study published in the Journal of the Nigeria Medical Association, 2D ultrasounds have a 99% accuracy rate. If gender is wrongly predicted, it’s likely that the anus was mistaken for female genitalia.

But what if baby is simply hiding his/her genitals?

Many ultrasound techs will spend a little time getting baby to move into a less modest position. Mama may be asked to lay on her side, use the restroom, drink a little juice, or move around a bit.

1. Cell-Free Fetal DNA Blood Test

Cell-free fetal DNA blood tests are blood tests designed to screen for chromosomal abnormalities. The tests can detect trisomy 13, 18, and 21 with a 91-99% accuracy. You may have heard of these tests by their brand names:

  • MaternitT21
  • Harmony
  • Panorama
  • Verifi

The bonus? They can also determine if your little one is a boy or girl. The gender predictor works by testing a small sample of the mother’s blood (which also contains a very small amount of fetal DNA).

Accuracy

Because the blood is being tested, the lab will be able to determine the XX (girl) or the XY (boy) in the blood sample accurately. However, the cell-free DNA tests are not recommended for women carrying multiples. For those women, the tests will not be accurate, as they cannot distinguish one baby’s DNA from another’s.

Cost

These tests can be quite costly, especially if insurance doesn’t cover them. Your insurance may cover the tests if you are high-risk (over the age of 35 qualifies). Before taking this test, it’s a good idea to call your insurance company with specific cost questions.

The bottom line

This gender predictor is accurate—as long as you’re pregnant with just one baby.

How about you?

Which gender predictor did you try? Were any of your gender predictions right?