Many parents find out their baby's sex during their mid-pregnancy ultrasound, usually done between 16 and 20 weeks. However, if the ultrasound technician's view is blocked, there are a few other ways to determine your baby's sex.
First, noninvasive prenatal testing is a blood test that detects tiny amounts of baby DNA in the mother. It can be done as early as 10 weeks, and can reveal sex in addition to some common chromosomal abnormalities. Some parents find out their baby's sex when their doctor orders a chorionic villus sampling – otherwise known as CVS – or amniocentesis test. These tests are usually offered to women who are at higher risk of having a baby with chromosomal problems, but the tests will also reveal the baby's gender. CVS is typically done at 10 to 13 weeks, and an amnio is typically done at 16 to 20 weeks.
A lot of patients ask me if these tests ever report the wrong gender. On rare occasions with ultrasound, the umbilical cord between the legs can look a lot like a penis. With the NIPT blood test, results are rarely incorrect, but errors are possible.
I should mention that there are also at-home gender kits advertised online that claim to be able to predict your baby's sex, but there's no scientific evidence that these tests really work. Some parents choose not to find out their baby sex in advance and relish that moment of surprise at birth. Others are chomping at the bit to know as soon as possible. Whichever way you go, you're in for an adventure.
Video production by Paige Bierma.