ABSTRACT
The fetal heart rate changes significantly across pregnancy. At 6 weeks of gestation, when the very early heartbeat is recognized, the heart rate is about 60–80 bpm, and it increases to 170 bpm in a few days; at 11–14 weeks, it averages 150–170 bpm, to remain in the range of 120–170 bpm thereafter; during fetal movements, the heart rate may reach 180–190 bpm to return promptly to less than 170 bpm.
