Electronic fetal monitoring (EFM), used during labor to gather data about the baby’s heart rate and the mother’s uterine contractions, has become increasingly common over the last three decades. The practice, which originated in the 1970s, rose in prevalence from about 50 percent of births in 1978 to 89 percent in 2012.
Fetal heart rate during labor and delivery can help show if the baby is getting enough oxygen, according to the American College of Obstetricians and Gynecologists (ACOG), allowing the opportunity for timely intervention if needed.
How is EFM done?
Electronic fetal monitoring may be external or internal. For external monitoring, two straps are placed around the woman’s abdomen. One strap contains a Doppler ultrasound transducer for measuring the fetal heart rate, and the other contains a pressure transducer for measuring uterine contractions. External monitoring provides the most accurate readings when the woman remains still, which may not happen consistently during labor and birth.
Internal monitoring is less restrictive in terms of the movement it allows, but the mother’s cervix must be at least partially dilated, the amniotic sac surrounding the baby must be broken, and the baby must be in a head-first position so that a tiny wire can be inserted into the skin on top of the baby’s head.
Is there an alternative to EFM?
The alternative to EFM is intermittent auscultation—listening to the baby’s heartbeat periodically with a fetal stethoscope or handheld Doppler device. Intermittent auscultation was the standard of care before the arrival of EFM.
Intermittent auscultation allows the woman to move about during labor, with benefits including shorter labor, fewer medical interventions, less severe pain, and greater maternal satisfaction. Recommendations vary on whether intermittent auscultation should occur every 15 minutes during the active stage of labor and every 5 minutes in the second stage of labor (ACOG) or every 15–30 minutes during the active stage of labor and every 5–15 minutes in the second stage (World Health Organization).
Does EFM improve labor and birth outcomes?
Studies have shown that women with high-risk pregnancies—those with preeclampsia, type 1 diabetes, preterm birth, and intrauterine fetal growth restriction—may benefit from EFM during childbirth. But the situation is different for women with low-risk pregnancies. For them, the use of intermittent auscultation instead of EFM helps prevent increased rates of cesarean deliveries and operative vaginal births (those involving use of forceps or vacuum extraction) that may occur because of false alarms.
ACOG evaluated the ability of EFM to “decrease complications, such as neonatal seizures, cerebral palsy, or intrapartum fetal death, while minimizing the need for unnecessary obstetric interventions, such as operative vaginal delivery or cesarean delivery.” The medical group’s review of EFM studies (the majority of which excluded women at high risk for adverse outcomes) suggested that the procedure failed to meet these goals. In fact, when compared to intermittent auscultation, the use of EFM:
- increased the overall cesarean delivery rate
- increased the risk of both vacuum and forceps operative vaginal delivery
- didn’t reduce mortality for monitored babies
- didn’t reduce the risk of cerebral palsy
- reduced only one risk (neonatal seizures)
Should I have EFM during labor?
Women with a high-risk condition will almost certainly have EFM recommended by their health care provider. Women with a low-risk pregnancy should find out their health care provider’s perspective on intermittent auscultation versus EFM and should share their own views. Monitoring options should be discussed well before labor begins.