A normal heart rate for a baby ranges from 120 to 160 beats a minute. Some believe a fast heartbeat indicates a girl, and a slower heartbeat indicates a boy. Unfortunately, there is no scientific proof of this. Don't pressure your doctor to guess based on this method because it is only a guess. Although I make this statement with my tongue placed firmly in my cheek, many people believe it's true.
Some people claim they're never wrong about guessing or predicting the sex of a baby before birth.
Again, there is no scientific basis for this. Your doctor is more concerned about your health and well-being and that of your baby. He or she will concentrate on making sure you and your baby, whether it's a boy or girl, are progressing through pregnancy safely and that you both get through pregnancy, labor and delivery in good health. Changes in You Your Growing Abdomen Beginning around week 20 or 21, your doctor began measuring you. You will be measured at every visit from now until delivery.