During pregnancy， the fetal heart rate will fluctuate depending on various factors. Initially， during the first trimester， the fetal heart rate will be between 90-110 beats per minute. As the pregnancy progresses into the second trimester， the heart rate will increase to around 120-160 beats per minute. This will remain the same throughout the third trimester， with occasional fluctuations.
It's important to note that the fetal heart rate will not constantly jump throughout the pregnancy. Instead， the heart rate will vary according to the following factors:
1. Activity level: When the fetus is active， the heart rate will increase slightly， and when they're sleeping， it will slow down.
2. Gestational age: As mentioned， the fetal heart rate will naturally increase with age. This is because their heart is developing and requires more oxygen-rich blood.
3. Maternal health: Any issues with the mother's health， like high blood pressure or certain medications， can affect the fetal heart rate.
4. Environmental factors: Any outside factors such as stress or excessive heat exposure can potentially impact fetal heart rate.
It's important to monitor fetal heart rate during pregnancy， which is typically done during prenatal checkups. A consistent and healthy heart rate can indicate overall fetal well-being. However， occasional fluctuations in heart rate are a natural part of fetal development and are usually not a cause for concern.
