Monitoring the baby's heartbeat is one way of checking babies' well-being in labour. By listening to, or recording the baby's heartbeat, it is hoped to identify babies who are becoming short of oxygen (hypoxic) and who may benefit from caesarean section or instrumental vaginal birth. A baby's heartbeat can be monitored intermittently by using a fetal Pinard stethoscope (special trumpet shaped device), or by a hand-held Doppler device. The heartbeat can also be checked continuously by using a CTG machine. This continuous CTG method is also called electronic fetal monitoring (EFM). It produces a paper recording of the baby's heart rate and mother's labour contractions. Whilst a continuous CTG gives a written record, it prevents women from moving during labour. This means that women may be unable to change positions freely or use a bath to help with comfort and control during labour. It also means that some resources tend to be focused on the needs to constantly interpret the CTG and not on the needs of a woman in labour.
This review included 13 trials involving over 37,000 women that compared continuous CTG monitoring with intermittent auscultation (listening). Most studies were not of high quality and the review is dominated by one large, well-conducted trial of almost 13,000 women who received one-to-one care throughout labour. In this trial, the membranes were ruptured artificially (amniotomy) as early as possible and oxytocin stimulation of contractions was used in about a quarter of the women.
Overall, there was no difference in the number of babies who died during or shortly after labour (about one in 300). Fits (neonatal seizures) in babies were rare (about one in 500 births), but they occurred significantly less often when continuous CTG was used to monitor the fetal heart rate. There was no difference in the incidence of cerebral palsy, however, other possible long-term effects have not been fully assessed and need further study. Continuous monitoring was associated with a significant increase in caesarean section and instrumental vaginal births. Both procedures are known to carry the risks for mothers although the specific adverse outcomes were not assessed in the included studies.