How to Auscultate Fetal Heart Rate Using a Fetal Doppler or Fetoscope

Pregnancy is a miraculous process. Many expectant mothers enjoy using a stethoscope to listen to their baby’s heartbeat during the second and third trimesters, as it helps them feel more connected to their developing fetus. But how exactly do you auscultate fetal heart tones with a stethoscope?

How to Auscultate Fetal Heart Tones Using a Stethoscope

Pregnant women and their family members can measure fetal heart rate at home using a stethoscope placed directly on the maternal abdominal wall. Starting at approximately 24 weeks’ gestation—and assuming a normal fetal position—the optimal location for auscultating fetal heart tones is the midline just below the umbilicus, or alternatively, slightly to the left or right of the umbilicus.

The normal fetal heart rate ranges from 120 to 160 beats per minute. When auscultating fetal heart tones, it is essential to distinguish them from other uterine sounds—particularly “blowing” uterine murmurs, which share a similar pulsatile frequency. These include: • Abdominal aortic sounds, whose frequency matches the mother’s pulse; • Fetal movement sounds—irregular, non-rhythmic noises produced when the fetus kicks or moves against the uterine wall. To auscultate fetal heart tones, have the pregnant woman lie down comfortably. First, locate the fetal back by palpation, then place the stethoscope on the corresponding area of the maternal abdominal wall to listen for fetal heart tones.

Using a stethoscope, one can hear the fetal heartbeat through the maternal abdominal wall. Expectant parents may practice listening and monitoring fetal heart tones at home. Fetal heart tones are characterized by a double sound—first and second heart sounds occurring in rapid succession—resembling the “tick-tock” of a clock: fast, clear, and regular. Prior to 24 weeks’ gestation, fetal heart tones are most commonly heard just below the umbilicus, either centrally or slightly to the left or right. Fetal heart rate typically increases when the fetus is awake. We hope this information proves helpful!