When a mother is admitted into the labor and delivery unit, doctors must monitor the baby’s heart rate continuously. This is a very important step because fetal heart rate indicates how well a baby is handling labor. Medical staff are trained in reading the printouts (called EFM tracings) that come from the electronic fetal monitoring unit, and should be able to identify if the baby’s heart rate is abnormal. If these tracings are abnormal, it is likely that the baby is experiencing fetal distress (which is nearly always caused by oxygen deprivation). EFM readings look like the following:
In most cases, babies can tolerate labor well, but there are some conditions that can make labor dangerous for the baby. If a baby is extremely premature, extremely small, or too large to fit through the birth canal, it is likely they are at higher risk of birth injury. This can mean it is safer for them to be delivered via C-section. Other conditions where it is likely that a baby will show signs of abnormal fetal heart rate can be found here.
- Murray, DM, et al. Fetal Heart Rate Patterns in Neonatal Hypoxic-Ischemic Encephalopathy: Relationship with Early Cerebral Activity and Neurodevelopmental Outcome. Am J Perinatol. 2009 Sep;26(8):605-12. doi: 10.1055/s-0029-1220774. Epub 2009 Apr 27.
- Goulding, RM, et al. Heart Rate Variability in Hypoxic Ischemic Encephalopathy: Correlation with EEG Grade and 2-y Neurodevelopmental Outcome. Pediatric Research (2015) 77, 681–687 doi: 10.1038/pr.2015.28.