Fetal heart rate is a standard method used during pregnancy to measure a baby's heart rate in utero. However, this term has wider synonyms that can also be used interchangeably in medical contexts. One of the synonyms is "fetal cardiac activity," which refers to the baby's heart's functioning and circulatory system. Another synonym is "fetal cardiac rhythm," which encompasses the baby's heart rate and the regularity of its beats. "Fetal heart sounds" is a term used to describe the noise generated by the baby's heart during a prenatal exam. Lastly, "fetal heart monitor" is a device used to measure fetal heart rate and rhythm during labor and delivery.