When Do You Find Out the Sex of Your Baby?

Advances in science mean it’s earlier than ever. Here’s what expectant parents need to know.

This story was produced in partnership with Huggies.

When do you find out the sex of your baby? It’s a question that little more than half of expecting parents want answered. A 20-year-old study suggests that around 40 percent of parents wait until childbirth. But a baby sex test — similarly commonly mislabeled as a baby gender test or baby gender reveal — is one of the few opportunities parents-to-be have to learn something significant about their new addition.

It’s rarely medically significant, but as fodder for imagining what parenthood might be like a baby’s sex is one of the most significant pieces of information parents can learn during pregnancy. Even if they’re determined to parent in a gender-neutral fashion and have no desire to throw a so-called baby gender reveal party, it can feel like a big deal.

So how does it work? It used to be that parents would have to wait until their mid-pregnancy ultrasound, typically at a gestational age of 18 to 22 weeks, to find out the sex of their baby. Before that, boys and girls look about the same on an ultrasound.

This method is simply a matter of the technician getting a clear view of the baby’s genitals, which can be tricky depending on how the baby is positioned in the womb. When this happens, parents typically go back in for another ultrasound on a later date in the hopes that the baby has shifted.

Nowadays, however, expectant parents can elect to have noninvasive prenatal testing, a test that analyzes small fragments of DNA circulating in a pregnant person’s blood. NIPT can detect chromosomal conditions like Down syndrome in addition to biological sex, so it’s probably something that even parents who don’t want to know the sex of their baby will go through. NIPT can be administered (i.e. blood can be drawn) at ten weeks, though results can take a couple of weeks to arrive.

Other options are chorionic villus sampling or amniocentesis, two procedures that are typically saved for women at increased risk of genetic and/or chromosomal problems because they are more invasive and slightly riskier than other methods.

The other options for parents-to-be include at-home tests available for purchase and others, like the baking soda test, that are more old wives’ tales than rigorous science — which doesn’t mean they can’t be a lot of fun).