Generally, the fetal heartbeat can be heard around the fourth month of pregnancy.

I. Timing of Hearing the Fetal Heartbeat during Pregnancy

The fetal heart is one of the earliest functional organs to develop in the body, and the fetal heart sound can directly reflect the condition of the fetus. Three to four weeks after conception, the fetal heart begins to beat. Around the fourth month of pregnancy, the fetal heartbeat can be heard near the midline below the umbilicus. As the fetus grows and its position changes, the location of the fetal heartbeat will also change. Since the fetal heartbeat is often transmitted from the fetal back, it is most clearly heard near the shoulder blades of the fetal back. Therefore, for a fetus in the cephalic presentation, the fetal heartbeat can be heard on both sides of the lower abdomen, while for a fetus in the breech presentation, it can be heard on both sides of the upper abdomen. For a fetus in the transverse presentation, it can be heard on the midline above or below the umbilicus.

II. Normal Fetal Heart Rate

The normal heart rate of a fetus is 120 to 160 beats per minute. When the fetus is smaller (less than 20 weeks), the heart rate tends to be faster. As the fetus grows larger, the heart rate tends to be slower. After fetal movement, the heart rate may temporarily increase above 160 beats per minute but quickly return to normal, which is a good indication of the fetus's health.

III. Importance of Attention to Abnormal Fetal Movement

If the fetal heartbeat exceeds 160 beats per minute or is less than 120 beats per minute, or if the heartbeat is irregular, with alternating fast and slow beats, or if there are pauses in the heartbeat, these are all abnormal signs. For pregnant women at 28 weeks of gestation, the time for listening to the fetal heartbeat should exceed 1 minute. If, within 10 minutes, the fetal heart rate is consistently lower than 120 beats per minute or higher than 160 beats per minute, or if there is a decrease in reactivity and fetal movement after an increase in fetal heart rate, immediate medical attention and examination are recommended. It is advisable for pregnant women to actively listen to their baby's fetal heartbeat, as this allows for better monitoring of the baby's growth and development. By closely monitoring the fetal heartbeat, any abnormalities can be detected and appropriate measures can be taken promptly.