What causes a tachycardia?

The normal fetal heart rate should be around 120~160. If the fetal heart rate is relatively fast, exceeding 160, you must understand the specific reasons at this time. This may be related to the pregnant woman's cold and fever. At this time, the pregnant woman's metabolism will be faster, which will also affect the changes in the fetal heart rate. In addition, if the pregnant woman herself has hyperthyroidism, it is also easy to cause this situation. Of course, it may also be related to some medications. Let us briefly understand this aspect.

What causes a tachycardia?

The normal heart rate of the fetus is 120 to 160 beats per minute. When the fetus is small (less than 20 weeks), the fetal heart rate is relatively fast; when the fetus is large, the fetal heart rate is relatively slow. After fetal movement, the fetal heart rate may briefly increase to more than 160 beats per minute, but then return to normal immediately. This is a good sign of fetal health. Fetal tachycardia refers to a fetal heartbeat exceeding 160 beats per minute. This situation is usually caused by severe fetal hypoxia, but not all fetal heart rate abnormalities are caused by hypoxia. Some fetuses have a fast heartbeat.

1. Fever:

The condition of the pregnant woman herself also affects the changes in the fetal heart rate. For example, if the pregnant woman has a fever, the fetal heart rate will often exceed 160 beats/minute.

2. Hyperthyroidism:

If a pregnant woman has hyperthyroidism, her heart rate will be very fast and the fetal heart rate will often exceed 160 beats per minute.

3. Taking medication:

If pregnant women take certain medications, such as salbutamol, which is used to protect the fetus during premature birth, or atropine, it can cause the mother and baby's heart rate to accelerate.

4. Umbilical cord entanglement:

In addition, in the case of umbilical cord entanglement, the entanglement may sometimes be aggravated due to fetal movement, and the fetal heart rate may continue to accelerate. If this happens before 36 weeks, the fetus is small and can move freely in the uterus, so the entanglement may be transient. If it happens after 36 weeks, the fetus is in a relatively fixed position and the entanglement may cause fetal distress or even death. Once the mother finds that the fetus' heartbeat is too fast, she must seek medical attention in time and monitor the fetal heartbeat at all times.