When Does a Fetus Have a Heartbeat?

If you've just received a positive pregnancy test, you probably have many questions. From "When will I feel my baby kicking?" to "When does morning sickness begin and end?" you likely have a lot on your mind. But if you're wondering when you'll hear your baby's heartbeat, fear not: The answer may be sooner than you think.

The "whoosh, whoosh" of your little one's earliest cardiac activity is one of the first things health care providers look and listen for at pregnancy confirmation visits. A transvaginal ultrasound may first detect this early heartbeat as early as 5 1/2 to 6 weeks.

Here's everything you need to know about your baby's heartbeat, from how it's monitored to when you can hear it.

What to Know About Your Fetus's Heartbeat

Embryonic cardiac activity (the earliest pulses of what will become your baby's cardiac cells) begins approximately 22 days after conception. This initial "heartbeat" won't be detectable yet—even though it's pulsing an average of 110 times a minute. But thanks to ultrasound technology, you (and a health care provider) should be able to hear and see your baby's heartbeat soon.

When Can You Hear a Fetal Heartbeat?

The earliest your baby's cardiac activity can be detected is between five and six weeks of pregnancy. At this early stage in your baby's development, you will actually be seeing the "heartbeat" through an ultrasound image rather than hearing it through a Doppler. This is because your baby is so small that your doctor can only detect the electrical activity through ultrasound.

The ultrasound machine may add sound so you can hear it, but you will also see the fast flicker of the cardiac cells communicating with one another.

If you don't see a heartbeat on the screen during your first prenatal visit, don't panic. It could still be too early, especially if you miscalculated how far along you are (which can happen if you have longer-than-average menstrual cycles). It's because of this common issue that many people don't see a health care provider for an ultrasound until they're a bit farther along in their pregnancies.

How Is a Fetal Heartbeat Monitored?

There are numerous ways to detect and monitor a baby's heartbeat in utero. Early on, most health care providers use transvaginal ultrasounds. These wand-like instruments do an internal scan of your organs, including your uterus.

As your pregnancy progresses, health care providers tend to use fetal Dopplers. These handheld devices can detect your baby's heartbeat as early as 8 weeks. However, many variables (such as the position of your uterus) may make it difficult at this early gestational age. Most fetal heart tones can be heard by 10 to 12 weeks.

Transabdominal ultrasounds may also monitor a baby's heartbeat during pregnancy.

Can You Hear a Fetal Heartbeat With a Stethoscope?

The short answer is yes, but not at first. Stethoscopes amplify internal noises, allowing health care providers to listen for a fetal heartbeat once the fetus is big enough, which usually isn't until they are 18 to 20 weeks.

But that's OK because most won't use a stethoscope to listen to a fetal heartbeat during pregnancy. Detecting a baby's heartbeat with a stethoscope is more challenging than with a fetal Doppler.

Is There an App To Hear a Fetal Heartbeat?

While the best method for measuring a baby's heartbeat is a fetal Doppler, apps like BabyDoppler can help you monitor, track, and record the sound of your little one's heartbeat. That said, it's important to note that research shows that these apps are not always accurate.

Always check with a health care provider before using Dopplers at home, as there are a number of concerns related to home use. The Food and Drug Administration (FDA) has issued a warning to people to use these types of devices with caution. Handheld Doppler devices are legally marketed as "prescription devices" and, according to the FDA, should only be used by, or under the supervision of, a health care professional. There is no evidence that Doppler devices cause harm to a developing baby or pregnant person.

Most importantly, it's never recommended to use apps or home Dopplers as replacements for a prenatal appointment with a health care provider.

Additional reporting by Krissi Danielsson.