Patient's question:
I did a fetal heart monitoring when I was one day away from 37 weeks. There were several peaks in the fetal heart rate, exceeding 160, while the rest were normal. What should I do?Doctor's answer:
Fetal heart rate is regulated by the sympathetic and parasympathetic nervous systems. The monitoring graph's curve, formed by recording the instantaneous changes in the fetal heart rate, allows us to understand the fetal heart's response during fetal movement and contractions, thereby assessing whether the fetus is experiencing hypoxia in the uterus. In normal pregnancies, fetal heart monitoring is performed weekly starting from the 37th week of pregnancy. If there are complications or comorbidities, it can begin as early as the 28th to 30th week of pregnancy. It is important to observe whether the fetal heart rhythm is irregular, such as suddenly speeding up or slowing down. The normal fetal heart rate is 120 to 160 beats per minute. If the fetal heart rate exceeds 160 beats per minute or remains consistently below 100 beats per minute, it indicates fetal hypoxia in the uterus and requires prompt treatment. [Edit this section]Symptoms and Causes of Abnormal Fetal Heart Rate
A normal fetal heart rate ranges between 120 and 160 beats per minute. If the fetal heart rate remains below 120 or above 160 for more than 10 minutes, it is considered abnormal. Currently, fetal heart monitoring devices are widely used. During monitoring, if an abnormal fetal heart rate pattern is detected, it often indicates an abnormal fetal heart rate. In most cases, abnormal fetal heart rate is a sign of fetal hypoxia in the uterus. The more severe the abnormality, the more severe the fetal hypoxia is likely to be. However, not all abnormal fetal heart rates are caused by hypoxia. Other factors, such as the mother's condition, can also affect fetal heart rate. For example, if the mother has a fever, the fetal heart rate may exceed 160 beats per minute. If the mother has hyperthyroidism, her own heart rate is often very fast, and the fetal heart rate may also exceed 160 beats per minute. Additionally, certain medications, such as salbutamol used for premature labor prevention or atropine, can cause an increase in both maternal and fetal heart rates.
A slow fetal heart rate may be caused by fetal hypoxia, but it can also result from certain medications the mother is taking, such as propranolol, which passes through the placenta and slows the fetal heart rate. If the fetal heart rate remains persistently slow, it is important to check for the possibility of congenital heart disease in the fetus. Additionally, after the 40th week of pregnancy, due to developmental issues in the fetal nervous system, the fetal heart rate may sometimes fall below 120 beats per minute. Therefore, when an abnormal fetal heart rate is detected, a thorough analysis is necessary to make an accurate judgment and appropriate management. If fetal hypoxia is confirmed, early delivery should be considered.