How Can a Doctor Tell If You Are Having a Boy or a Girl?

One method doctors use to determine if an unborn child is a boy or girl is ultrasound, according to WebMD. By 20 weeks, the fetus is usually developed to the point the doctor can determine its sex. However, ultrasound images are not foolproof, and it is possible to misinterpret the results. Parents who do not want to know the baby’s sex before birth should inform the health care provider before the procedure begins.

The medical community considers ultrasounds safe for both the baby and mother. Normally the test is noninvasive, with a gel placed on the mother’s belly to improve the quality of the image. It does not use X-rays, which could harm the baby, warns WebMD. If an ultrasound is required to check the baby’s health early in the pregnancy, the medical care provider may insert a wand into the vaginal canal for a clearer picture. These early ultrasounds can help determine the gestational age or due date and the presence of more than one fetus.

The primary reasons for the ultrasound are checking the health of the baby. During the procedure, the doctor is able to check the development of the fetus and the health of the placenta. The images also show the arm, legs and heartbeat of the child, reports WebMD.