Fetal Heart Rate: Can It Predict Gender?


When is an old wives’ tale not really an old wives’ tale? When the myth started in the scientific community.

There is a popular notion that you can predict the gender of your baby based on his or her fetal heart rate. Most proponents of this theory suggest that:

  • A fetal heart rate of 140 bpm (beats per minute) or higher indicates that you are carrying a baby girl.
  • A fetal heart rate of less than 140 bpm indicates that you are carrying a baby boy.

Many have dismissed this as an old wives’ tale. That hardly seems plausible, however, since we have only been able to monitor fetal heart rates in recent decades. Fetal heart rate monitoring made its debut in the 1960s. So, where did the idea get its start?

It turns out that it was the medical community itself that got this rumor started. While the technology for monitoring fetal heart rates was still fairly new, some doctors speculated that you may be able to determine a baby’s gender by its fetal heart rate. Studies were conducted, but were generally inconclusive. Still, it didn’t stop the theory from gaining widespread acceptance, especially outside of the scientific and medical community.

At least three studies (two in the United States and one in the United Kingdom) have been conducted which have shown that fetal heart rate cannot accurately predict a baby’s gender.

The studies showed that a number of factors determined babies’ fetal heart rates, including:

  • Gestational age. Between eight and ten weeks, your baby’s heart rate will generally be between 170 and 200 beats per minute. During your second trimester, your baby’s heart rate will generally be between 120 and 160 bpm.
  • Baby’s movement. When your baby is active and kicking about inside you, her heart rate will go up. When she’s resting, her heart rate will go down. In that respect, she’s no different than you are.

Unfortunately, the studies do not show any correlation between fetal heart rate (at any stage of gestation) and baby’s gender. In fact, they show fairly conclusively that you cannot predict a baby’s gender by his or her heart rate.