You’ve probably heard of many ways to predict whether you’re having a boy or a girl. Some of these old wife’s tales are quite popular, especially on forums and various pregnancy sites you’ll find online. The baking soda gender test is particularly easy and inexpensive, but does it work? Here’s what the science has to say, as well as some more reliable ways to learn the sex of your baby.

How does it work?

You can do this test at your own home using supplies you likely already own. All you’ll need is some baking soda in a small container and another clean container to catch your urine.

To collect your urine, wash your hands, sit on the toilet, and hold the container under yourself while you void a small amount. For extra safety, you may consider wearing latex gloves.

First morning urine is preferred with this test, since drinking water throughout the day is thought to dilute the urine and skew the results.

You’ll need about equal parts urine to baking soda. There’s no consensus on specific measurements. Once you have these two crucial ingredients, slowly pour the urine into the baking soda and watch to see if it fizzes.


If the urine fizzes or sizzles in the baking soda, you’re supposedly having a boy. If nothing happens and it stays flat, you’re supposedly having a girl.


Performing this test may make you feel a bit like a scientist in a lab. And some science is at play here. Baking soda is also called sodium bicarbonate. It reacts with most acids, so the fizzing, if it occurs, is a chemical reaction between the acid in your urine and the baking soda base.

Things that may make your urine acidic include anything from eating certain foods to being dehydrated. For example, if you’ve had bad morning sickness with lots of vomiting, your urine may be more acidic. High acidity in the urine may be linked with a higher instance of urinary tract infections. Lowering the acidity may be as simple as eating less meat or taking antacids.

Your result with the baking soda gender test may vary depending on:

  • the day you take the test
  • what you’ve eaten or had to drink
  • your urine’s pH level

None of these factors have anything to do with the sex of your baby.

So, exactly how accurate is this test? This test only works 50% of the time, which is the same as flipping a coin. And that doesn’t have anything to do with the validity of the test itself. You have about a 50 percent chance of conceiving a boy or girl.

Gender ultrasound

Your baby’s sex is determined at the moment of conception, right when the sperm meets the egg. Many people find out the sex of their babies much later, though, during an anatomy ultrasound. This scan is usually performed around week 20. At this appointment, your doctor will examine all your baby’s parts from head to toe, including their genitalia.

One study revealed that 2D ultrasound is incredibly accurate. It correctly identified genitalia 99 percent of the time in over 200 cases. That said, there are some instances where it may be difficult to decipher genitalia of a fetus. For example, the position of the baby in the womb could make it hard to see their genitalia.

Other gender tests

Some people find out the sex of their babies as early as 9 weeks into their pregnancies using a simple blood test called a cell-free DNA screen (Verifi, MaterniT21, Harmony). The main purpose of the test is to screen the fetus for possible genetic issues. The test also identifies sex chromosomes. One test, Panorama, claims it is 100 percent accurate at determining fetal sex. It works by detecting the presence or absence of the Y chromosome, which would indicate if you’re carrying a boy.

Genetic testing is another way you may learn your baby’s sex before the 20-week mark. Amniocentesis is typically performed between weeks 15 and 20. Chorionic villus sampling (CVS) is typically performed between weeks 10 and 13. Both of these tests require a medical reason, not just finding out the sex of a baby. These tests are more invasive, but also more accurate than cell-free DNA screens. They look for genetic abnormalities in the chromosomes. They do carry risks, though, so they aren’t generally recommended unless you:

  • are over 35
  • have a family history of genetic disorders
  • have received positive results from a cell-free DNA screen


While there isn’t any formal research to support the accuracy of the baking soda gender test, it can be a fun way to pass the time while you wait for the arrival of your baby. Before you pick out pink or blue accents for the nursery, however, it’s smart to wait for a genetic scan or your anatomy ultrasound.

Ready to give it a try? Shop for baking soda.
