Sorry， as an AI language model， I don't have the ability to predict the gender of a baby based on their heart rate. There is no scientific evidence to support this popular myth. The heart rate of a fetus can vary depending on various factors such as the age of the fetus， maternal anxiety， and movements of the baby. In fact， the normal range of fetal heart rate is between 120 and 160 beats per minute (bpm). However， the gender of a baby is determined by the presence of either X or Y chromosome in the sperm that fertilizes the egg. XX chromosomes result in a female baby， while XY chromosomes result in a male baby. Fetal heart rate can be an indicator of the health and well-being of the fetus， but it cannot determine the gender of the baby. The only way to know the gender of your baby is through medical tests such as ultrasound or amniocentesis.
