The accuracy of the report will depend on many factors, including the age of the baby, the equipment used, the technician, and the baby. However, there are certain signs in boy and girl ultrasound pictures that the technician uses to determine the gender of your baby. You will see below there is more to a girl ultrasound picture than the absence of a penis. In fact, particularly early on in pregnancy, a clitoris and a penis are roughly the same size and shape. The clitoris situated between the labial lips looks like a hamburger between two buns, or three lines. The labia would be the buns of the hamburger and the clitoris would be the meat. This may be harder to see with some babies, which is why there are multiple signs to look for during an ultrasound. The gestational age and position of the baby play a part in what can be seen. Seeing an erection may bother some parents. But don’t worry—it is normal for boys to have erections. You will notice these after birth as well, during diaper changes.

A Word From Verywell

The greater availability of 3D and 4D ultrasounds has changed how ultrasounds determine a baby’s gender. Ultrasounds are often more accurate because you can see body parts more clearly, as opposed to guessing from shadows. Remember, before 18 weeks the clitoris and penis are roughly the same size and can easily be mistaken. Although you understandably really want to know the gender of your baby and prepare for his or her birth, it’s best to be patient. No matter what type of ultrasound you use, there will always be errors, especially with early ultrasounds.