Fetal Heart Rate
The fetal heart rate can, typically, be heard on ultrasound at six weeks of pregnancy, depending on the mother’s body size and the method used to find the fetal heart rate. At around the tenth week of pregnancy, roughly three weeks before the second trimester begins, the fetal heart rate will peak at around 175 beats per minute. By week fifteen, which is during the very early part of the second trimester, the fetal heart rate will have dropped down to around 140 beats per minute.
It was once thought that the fetal heart rate could predict your baby’s gender. It was thought that, if a baby’s heart rate was under 140 beats per minute that it would be a boy and that if it was over 140 beats per minute it would be a girl. The theory behind this idea was that, because women usually have a higher metabolic rate than men, that unborn girls would have a slightly higher pulse rate than unborn boys. However, research disproves this idea, and demonstrates that there is not necessarily a connection between the fetal heart rate and the gender of your baby.