How to Listen to an Unborn Baby’s Heartbeat with a Stethoscope

Listening to the heartbeat of an unborn baby can be a fascinating and emotional moment for expectant parents. This can typically be done after the 20th week of pregnancy. Here’s how to accomplish this with a stethoscope, including tips for the best results.

Steps to Listen to an Unborn Baby’s Heartbeat

1. Choose the Right Stethoscope

A fetal stethoscope, also known as a Pinard horn, is specifically designed for this purpose. However, a regular stethoscope can also work, particularly one with a bell end or a combination bell and diaphragm that is switched to the bell.

2. Positioning

Have the pregnant person lie down in a comfortable position, preferably on their left side. This position can help improve blood flow and make it easier to hear the heartbeat.

3. Locate the Fetal Heartbeat

a. Find the Right Spot Start by placing the stethoscope on the belly and moving it around gently to find the heartbeat. The best location to listen for the heartbeat is usually on the lower abdomen.

b. Listen for the Rhythm The fetal heartbeat typically sounds like a rapid thumping, usually between 120 to 160 beats per minute.

4. Adjust the Pressure

You may need to adjust the pressure of the stethoscope against the abdomen to get a clearer sound.

5. Be Patient

It may take some time and patience to find the heartbeat, especially if the baby is moving or if the position is not optimal.

Tips for Listening to the Fetal Heartbeat

Timing

The best time to listen is when the mother is relaxed, such as after a meal or when lying down.

Use of Gel

Although not necessary with a regular stethoscope, sometimes using a little gel, like ultrasound gel, can help improve sound transmission. However, this is less common with a regular stethoscope.

Additional Tips

As Dr. Marcus answered, you’d have the best chance with a Pinard stethoscope. This device resembles the first stethoscopes used and is designed so that the physician, who is usually a man, does not place their ear directly on the woman’s chest or abdomen. This relatively simple design helps detect the soft sound of a fetal heart. It is generally possible even with an ordinary stethoscope that has a bell end or is a combination bell and diaphragm.

Pinard stethoscopes are still available as newly-manufactured ones or can be sought as expensive antiques. They are usually made of wood but newer ones are mostly made of metal. If you use a metal one, warm it up with your hands before applying it to the mother’s abdomen.

Ultrasound Doppler stethoscopes can be used to hear a baby’s “heartbeat,” but it is not the actual heart sound. It results from the movement of the heart muscle contracting, affecting the ultrasound frequency, and the difference between what is transmitted in and what the baby’s heart or anything else that moves reflects back, resulting in the Doppler sound.

I would caution about using any such ultrasound fetal heart detector if it is not an FDA-approved device. There are many inexpensive ones available, but the FDA has specifications for the sound output power. While ultrasound is mechanical and not electromagnetic, it is a form of energy and should be used with caution. These devices should come with recommendations for how often and for how long they can be used. That’s the advantage of an ordinary stethoscope—the passive device functions like a microphone, receiving sound without transmitting anything.

Additionally, you may also hear the mother’s heartbeat. The heart rate is usually the best way to determine if it is the fetal heart. The fetal heart rate is typically 130–140 beats per minute, with a usual range of 110–160 BPM. The mother’s heart rate is usually lower, around 70–80 beats per minute, resting. A mother in excellent aerobic condition may have a normally slower heart rate. If you hear a heartbeat with a stethoscope slower than 120 BPM, it is likely the mother’s.

You can also feel the mother’s pulse and see if it synchronizes with the heartbeat you hear. This can help confirm the origin of the sound. For comprehensive prenatal care, it is important for expectant parents to have regular check-ups with healthcare providers.