Predicting a baby's gender is a fascination that has gripped people for a long time. Of the many beliefs that surround this issue, one of the most popular is using the baby heart rate to determine the gender of the unborn child. The basic theory is that a baby boy will have a heart rate of less than 140 beats per minute, and a baby girl will have a heart rate of more than 140 beats per minute. Although this theory is widely believed, there is no scientific proof that there is any connection between gender and heart rate of a baby.
A baby's heart rate actually varies throughout the pregnancy. During the first weeks of pregnancy, the baby heart rate is closely matched to the mother's heart rate, or an average of about 85 beats per minute. This rate slowly increases by an average of about three heartbeats a day. After about five weeks, the heart rate of both male and female babies has increased to about 175 beats per minute, and this average then slowly decreases throughout the rest of the pregnancy. Research has shown that the difference between the average male fetal heart rate and the average female fetal heart rate is very small — less than half a beat per minute — which has led researchers to conclude that there is no correlation between fetal heart rate and gender.
A fetal heart rate is classified as normal when it falls between 110 beats per minute and 180 beats per minute. The heart rate of a baby also might change throughout the day. A baby who is active or moving will generally have a higher heart rate then a baby who is still or sleeping. Thus, a higher baby heart rate is actually more indicative of the baby's activity level than of its gender.