There is nothing quite like hearing your baby’s heartbeat for the very first time — it’s one of those moments that brings you to tears! But once that tender moment passes and your midwife or doctor announces the heart rate, you may be thinking “is that a normal fetal heart rate?”
To put your mind at ease, we’ll break it all down for you, including:
- When you can hear baby’s heartbeat for the first time
- The range of a normal fetal heart rate
- The different ways to measure baby’s heart rate
- Plus, whether baby’s heart rate can predict sex
When Can You Hear Baby’s Heartbeat for the First Time?
A baby’s heart starts to beat around 6 weeks.
- If you opt for an early ultrasound, you may get to hear baby’s heartbeat, or even see it beating on the monitor, as early as 6 weeks.
- Otherwise, you’ll probably hear baby’s heartbeat via a doppler at your first prenatal visit somewhere between 8 to 12 weeks, sometimes even later.
- Mamas who opt to limit, or forgo, ultrasounds may not hear baby’s heart beat until closer to 20 weeks when it’s strong enough to hear with a fetoscope. (More on the difference between a doppler and a fetoscope below!)
What’s a Normal Fetal Heart Rate?
A normal fetal heart is between 120 and 160 beats per minute. (source) This is a lot faster than most parents expect to hear. In fact, it’s almost twice that of an adult heartbeat.
But it’s important to note that the heart rate can, and does, change depending on the gestational age of the baby. When the heart is first beating and still developing, it is normal for the fetal heart rate to start out at a much slower rate, increasing daily, until it starts to stabilize and beat within the expected range around the 12th week of pregnancy.
Take a peek at this fetal heart rate chart to get an idea of how it changes week to week:
Once baby is born, he/she will maintain the 120-160 bpm average range for the first few hours, but after that:
- The neonate (first 28 days of life): 100-165 bpm while awake and 90-160 bpm while asleep (source)
- 1-2 months: 100-150 bpm while awake and 90-160 bpm while sleeping
- 1 year: 70-110 bpm while awake and 80-120 bpm while sleeping
- 12 years old: 60-100 bpm—close to that of an adult.
Fascinating, isn’t it?
What If Baby’s Heart Rate Doesn’t Fall Within the Normal Range?
It can be severely anxiety-inducing to discover baby doesn’t have a normal fetal heart rate. Remember: Baby’s heart rate isn’t always consistent in the early stages of pregnancy. It varies from baby to baby and even pregnancy to pregnancy.
The following factors, many of which are relatively benign, may affect baby’s heart rate:
- Gestational age: A baby’s heart rate starts out slower in the very beginning, then speeds up. It levels off to the normal fetal heart rate range of 120-160 bpm by mid-pregnancy. If your baby’s heart rate is out of range, check your due date first. There’s a chance dating is off!
- Blood sugar levels: When accounting for maternal age, BMI, diabetes duration, and gestational week, researchers found higher glucose levels correlated to a higher fetal heart rate. Similarly, low blood glucose levels contribute to a lower fetal heart rate.
- Fetal activity: As baby develops, so does the nervous system. And our parasympathetic nervous system is what makes our heart rates go up or down based on activity or stress. If baby is sleeping in there, he/she will have a lower heart rate; If baby is active, he/she will have a higher heart rate. This variability is a good thing — studies show heart rate variability is one of the best markers of fetal health, as it shows resiliency.
- Mama’s diet: Food and beverages like coffee, chocolate, and sugar are stimulants, and can affect whether baby has a normal fetal heart rate at that moment. If you consume these things prior to an ultrasound, it can cause a temporary increase in heart rate.
A normal fetal heart rate is an indicator of good fetal health. A baby may be in distress if their heart rate falls outside of the normal fetal heart rate range. Unfortunately, an abnormal fetal heart rate can indicate a heart condition or a miscarriage in process. However, the odds are in your favor that you’ll have a healthy baby.
It’s important not to jump to conclusions, though. Heart rate can be measured incorrectly and/or fluctuate significantly. Most midwives or doctors won’t diagnose a genetic condition or a miscarriage on one heartbeat reading. You may have a follow-up ultrasound or have HCG levels tested.
If you are concerned about your baby’s heart rate, talk to your provider—there’s likely a good explanation!
Help! Doppler vs. Fetoscope
If you haven’t yet hear baby’s heartbeat for the first time, you may be wondering about your choices.
Fetoscopes are safe and carry no risk, but you have to wait to hear baby’s heartbeat. There is some evidence that dopplers expose the fetus to extra high-frequency waves. However, in the care of a professional who knows how to operate them, they are generally regarded as safe.
Learn more about fetal heart monitors in this post.
Can I Use an At-Home Fetal Monitor to Check Baby’s Heart Rate?
As a general rule, at-home fetal monitors are not recommended. A lot of mamas purchase these pocket dopplers, for reassurance and to connect with baby on a regular basis. While that’s tempting, these devices are not approved by the Food and Drug Administration.
Although there is a lack of evidence of any harm due to ultrasound imaging and heartbeat monitors, prudent use of these devices by trained healthcare providers is important. Ultrasound can heat tissues slightly, and in some cases, it can also produce very small bubbles (cavitation) in some tissues. — Shahram Vaezy, a biological engineer from the FDA
The long-term effects of tissue heating and cavitation are not known. Therefore, fetal heart monitors should be done only when there is a medical need by trained professionals, including midwives and doctors.
Can Baby’s Heart Rate Predict Baby’s Sex?
Studies have debunked this gender predictor (the old wives’ tales say girls’ heartbeats are faster and boys are slower), but many midwives and mamas swear by it.
Fetal heart rate can change often — going up or down — for reasons that have nothing to do with baby’s sex.
Still, it can be fun to guess. You might speculate that baby’s a boy if the heartbeat is consistently in the low 130s!
Also, fun fact: During labor girls do tend to also have a higher heart rate.
How About You?
What is your experience with fetal heart rate? How did you feel when you first heard it? Did your baby’s fall within range of the normal fetal heart rate?