How many weeks is fetal heart rate monitoring usually done?

Girls need to do fetal heart monitoring during pregnancy. Fetal heart monitoring needs to be done in the obstetrics and gynecology department of the hospital. If the fetus is at risk of disease, it can be detected through fetal heart monitoring. Fetal heart rate monitoring is a good pregnancy check measure that allows mothers to have close contact with their children and to more vividly perceive the development of the fetus in their bodies. So, how many weeks is fetal heart rate monitoring usually performed?

1. How long does it take to do fetal heart monitoring during pregnancy?

1. When should fetal heart monitoring be performed?

Normally, fetal heart rate monitoring is done at every prenatal checkup starting from the 32nd week of pregnancy, and every week after the 37th week of pregnancy. High-risk pregnant women, or those suffering from complications such as pregnancy-induced hypertension, should start doing it in the 28th week of pregnancy. After the doctor determines the location of the fetal heart, the expectant father can listen to the fetal heartbeat directly with his ears at home, and can do it many times a day.

2. Duration of each fetal heart monitoring session

Under normal circumstances, each fetal heart monitoring session will last about twenty minutes, and the time may be longer under abnormal circumstances. High-risk pregnant women need to be hospitalized for fetal heart monitoring after 35 weeks of pregnancy, and if necessary, the monitoring should last for > one hour at a time.

Second, the method of detecting fetal heart rate

1. Home fetal heart rate monitoring

(1) Stethoscope: Although it is cheap, it requires technical skills because the fetal heart rate is not easy to find. If you want to use this method, you need the help of a professional.

(2) Fetal heart rate monitor or fetal talk monitor: Both instruments use Doppler auscultation technology and can display the fetal heart rate on the LED. The latter is a highly intelligent instrument that needs to be connected to a mobile phone software for use. It can monitor at home and has multiple functions such as listening to, recording fetal sounds and counting fetal movements.

(3) Counting fetal movements: This method has a high accuracy rate and is highly recommended by doctors. Under normal circumstances, the number of obvious fetal movements is ≥3 to 5 times in 1 hour and >30 to 40 times in 12 hours. If the fetal movement is less than 10 times in 12 hours, it means that the fetal movement has decreased and it is recommended to seek medical attention in time.

(4) Listening to the fetal heart rate: During the prenatal check-up, you can find out where the fetal heart rate is. You can ask your family members to listen to the fetal heart rate at home in the morning, noon and evening. It takes two to three minutes at a time. One hundred and twenty to one hundred and sixty beats per minute is normal.

2. Fetal heart rate monitoring during prenatal check-up

(1) Ultrasound is used to record the instantaneous changes in the fetal heart rate to form a curve graph, which helps doctors understand the condition of the fetus during fetal movement and infer whether there is intrauterine distress.

(2) There are two probes in total. One is a pressure sensor tied to the top of the uterine head, which can detect the presence and intensity of uterine contractions. The other is placed on the fetus' chest or back.

(3) The fetal heart rate monitor displays two lines. The upper one represents the fetal heart rate, with a normal fluctuation range of 120 to 160 beats/min; the other line depicts the intrauterine pressure. Under normal circumstances, the basal fetal heart rate presents a wavy straight line. It will rise when there is fetal movement, and the line indicating intrauterine pressure will also rise, and then recover and be around 20 millimergs of mercury.

(4) The monitor plots the number of heart beats in each fetal heart cycle on a graph, showing changes in the fetal heart baseline. This change reflects the fetus's central nervous system autonomic nervous system regulation and cardiac conduction function.

3. Notes

(1) It uses the principle of ultrasound and will not cause harm to the fetus.

(2) Do not undergo the examination when you are hungry. It is recommended that you maintain a comfortable position after going to the toilet, such as semi-recumbent or sitting, and each examination should last about 20 minutes. The inspection will last more than twenty minutes.

(3) If the fetus is not moving, it may be asleep. You can gently shake the abdomen to wake it up. If you are not satisfied with the results, you can continue and the expectant mother does not need to worry too much.

(4) If there are high-risk factors such as post-term pregnancy, then it should be performed ≥2 times a week until delivery if there are abnormalities in the fetal heart rate.