Fetal Heart Rate Chart

The normal resting heart rate of a woman can be anywhere between 60-100 bpm. A resting heart rate (RHR) between 60-70 bpm is considered as good heart rate for a woman. During pregnancy, a woman may experience an increase of 10-20 beats in her RHR, depending upon various factors like age, weight, overall health, etc. Normal fetal heart rate is quite different from these figures and you might be confused after hearing the beats of your baby in the womb.

Fetal Heart Rate Chart by Week

Age or Size of the Fetus	Normal Fetal Heart Rate
2 mm embryo and gestational sac diameter of 20 mm	75 bpm
5 mm embryo and gestational sac diameter of 30 mm	100 bpm
10 mm embryo	120 bpm
15 mm embryo	130 bpm
5th Week (Beginning)	80-85 bpm
5th Week (End)	103 bpm
6th Week (Beginning)	103 bpm
6th Week (End)	126 bpm
7th Week (Beginning)	126 bpm
7th Week (End)	149 bpm
8th Week (Beginning)	149 bpm
8th Week (End)	172 bpm
9th Week (Beginning)	155 bpm
9th Week (End)	195 bpm (average 175 bpm)
12th Week	120-180 bpm (average150 bpm)

The above chart shows how the heart rate of the fetus keeps on changing during the pregnancy. The figures may vary from fetus to fetus depending upon several conditions. You should consider the average heart rate of the fetus while comparing the heart rate of your baby.

Fetal Heart Rate

The heartbeat of a baby in the womb is also known as 'Fetal Heart Tone' (FHT). It is measured with the help of a fetal ultrasound doppler. FHT keeps on changing during the stages of the pregnancy. Like in adults, FHT is also measured in beats per minute. It indicates how many times the heart of the fetus beats in a minute. As you know, 40-42 weeks period of pregnancy is divided into three trimesters. Though fetal heart starts beating at around 5th week, the beats are usually audible from 18th week onwards. But don't panic if you are not able to hear the heartbeats in the 18th week. It will depend upon your own weight, position of the baby, location of the placenta, etc. You may be able to hear the beats in the next week or in the 20th week. It's quite normal. You can hear the beats with the help of a stethoscope or fetoscope. The modern ultrasound technology has made it possible to hear the fetal heartbeats as early as in the 8th week.

You must have noticed that in the 5th week, the FHT and the mother's heart rate (80-85 bpm) are almost the same. But then the FHT increases with an amazing speed, at about 3 beats per minute per day for the whole month! After 9th week, it lowers down and comes to about 150 bpm (average) in the 12th week. The normal FHT range after 12th week is 120-160 bpm. This fixed pattern of change in the FHT helps estimate the age of the fetus.

During the second and third trimester, no major changes in the FHT are noticed. The FHT lowers slightly during the last ten weeks, in the last trimester. But it is still quite higher than the heart rate of an adult (about twice). A range of 100-160 bpm is considered as normal range of FHT. Absence of heartbeats for a week or more is a sign of impending miscarriage. Placental or umbilical cord problems, psychological or emotional stress on the pregnant woman, excessive physical exertion by the pregnant woman or any other health complications can lead to abnormally low or high FHT. Moreover, the heart rate of the fetus may change during physical activities performed by the mother and during sleep. The rate can be quite different at different periods of time during the same day.

Average FHT varies from fetus to fetus, and keeps on increasing and decreasing during the pregnancy. It can be as high as 180 bpm or as low as 100 bpm. Even 90-110 bpm can be considered as normal heart rate for a 6 weeks old fetus, depending upon the situation. At 9 weeks, 140-170 bpm can be considered as normal heartbeat. Very low heart rate at 5-8 weeks (less than 90 bpm) is referred to as fetal bradycardia and it indicates high risk of miscarriage. Thus, measurement of fetal heart rate helps assess the health of the fetus.