If the fetal heart rate is 158, is it a boy or a girl? During pregnancy check-ups in the hospital, fetal heart rate is a very important indicator. Many expectant parents will guess the gender of the fetus based on the fetal heart rate. So if the fetal heart rate is 158, is it a boy or a girl? We will discuss this issue from the following aspects. 1. The connection between fetal heart rate and fetal gender. First, let’s find out whether there is a connection between fetal heart rate and fetal gender. In fact, there is no necessary connection between fetal heart rate and fetal gender. Although some people