Fetal Heart Rate at 20 Weeks

The heart of your baby is one of the earliest developing organs, and you can actually hear that tiny heartbeat early in your pregnancy. It is important to understand that your baby's heart goes through several changes during pregnancy. With you nearing your due date, there will be a constant change in the size, function, and rate of your baby's heart.

What Is the Normal Fetal Heart Rate at 20 Weeks?

In the utero period, a normal fetal heart rate (FHR) is anywhere between 120 and 160 beats per minute (BPM). You can have it measured sonographically when you are 6 weeks pregnant. The normal FHR keeps changing during gestation and can get up to 170 beats per minute at 10 weeks. However, the heartbeat usually becomes slower from 10 weeks and is usually around 130 bpm at term. Fetal heart rate at 20 weeks is somewhere around 140. Here is a chart for more details about the normal heart rate at different stages in pregnancy.

Fetal Age/Size

Normal Fetal Heart Rate in Beats Per Minute

2mm embryo with a 20mm gestational sac


5mm embryo with a 30mm gestation sac


10mm embryo




Up to 5 weeks


At 5 weeks


6 weeks


7 weeks


8 weeks


9 weeks

155-195, with average being 175

12 weeks

120-180, with average being 150

After 12 weeks

120-160, with average being 140

Fetal Heart Rates of Some Babies for Your Reference

"After I had my first ultrasound scan, I was told that my baby's heart rate was 161. I considered it too high, but my doctor told me not to worry. His heart rate was 123 at my next u/s, and it was again a surprise for me. I thought it was too low, but my doctor said that our little angel is doing just fine."

"At 16 week, my baby girl's heart rate was 164. I could feel her bouncing everywhere. It all became rather quiet at week 20. My doctor then told me that it is fine for a baby's heart rate to go up and down with movement."

"I am now just past 18 weeks and had an ultrasound yesterday stating my baby's hear rate was around 129. My doctor said it was great. My previous ultrasounds had shown my baby's heart rate around 140, so 129bpm was a bit surprising at first. But my doctor said everything is just perfect."

How to Keep Your Baby's Heart Healthy

Fetal heart rate at 20 weeks shows that your baby's heart is developing and undergoing several changes. While you cannot control certain things, you can still take steps to keep your baby's heart healthy. For instance:

  • Take folic acid supplements before and during pregnancy to lower the risk of congenital heart disease in your baby.
  • Stop smoking because it increases your risk of having a miscarriage. Maternal smoking in early pregnancy usually leads to heart defect, including anomalies of the vessels and valve.
  • Maintain your blood sugar levels at normal in case you have gestational diabetes or type-2 diabetes. Uncontrolled blood sugar levels lead to an increased risk of heart defects in babies.
  • Do not use Accutane because it may cause fetal heart defects.
  • Stay away from recreational drugs and alcohol during pregnancy.

Keep in mind that though it is important to do whatever you can to ensure that your baby's heart is healthy, certain things are out of your control. You cannot do anything if chromosomal abnormalities lead to heart defects or other birth defects for that matter. Understand that this is never your fault.

When Can You Hear Your Baby's Heart Beat?

Your pregnancy has three parts or trimesters. It means the journey of your baby from week 1 to week 42 has three stages. So many factors can affect when you can hear your baby's heartbeats. Your body weight, position of your baby, and the placenta's location can all come into play. It is usually possible around 18-20 weeks in most cases, but sometimes, you can hear it at about week 12- this is with the help of a fetoscope or stethoscope. With ultrasound, it is possible to hear your baby's heartbeats at 8 weeks. You do not need to worry though if you cannot hear fetal heart tone (FHT) at 12-14 weeks of pregnancy.

Is There a Connection Between Fetal Heart Rate and Age?

Besides fetal heart rate at 20 weeks, you may also wonder if your baby's heart rate can somehow show his/her fetal age. Understand that your baby's heart starts beating when you are 5 weeks pregnant. The fetal heart rate (FHR) is usually faster as compared to the heart rate of an adult. Your baby's heart rate is likely to be the same as your resting heart rate (80-85bpm) during the week 5 of pregnancy. The heart rate goes up quickly after week 5 and continues to go up until your week 9 of pregnancy. Then, it settles down a bit and stays around 150bpm, but it starts coming down a bit after 12th week and may be as low as 120bpm. Since the increase in the heart rate follows a specific pattern, it is possible to tell fetal age considering the fetal heart rate.

A very important thing to understand is that your baby's heart rate is likely to change with your movements. The heart rate measured while resting can be quite different as compared to the rate measured during other activities. Therefore, do not worry about a change in your baby's heart rate, and if you really think something is not right, be sure to talk to your doctor instead of worrying. 

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