Cardiotocograph

A device used in obstetric care that simultaneously records a fetus's heart rate and the mother's uterine contractions, most often through two sensors strapped to the mother's abdomen, so that clinicians can watch for patterns suggesting the fetus is under distress during labor or in the period leading up to it. One sensor uses ultrasound to detect the fetal heartbeat and the other detects the tightening of the uterus during a contraction, and the two traces are displayed together on a strip or screen so a clinician can judge whether the fetal heart rate is responding normally to each contraction. Electronic fetal monitoring of this kind came into hospital use beginning in the 1960s and 1970s, replacing intermittent listening with a handheld device with a continuous recorded trace that could be reviewed over time and kept as part of the medical record. Its widespread adoption has been debated by researchers, since continuous monitoring in low-risk labors has not been shown to reliably improve outcomes for the baby and is associated with a higher rate of cesarean delivery, so guidelines in many places now reserve continuous use for pregnancies judged to be at higher risk.