EP 9: Electronic Fetal Monitoring During Labor


Electronic fetal monitoring (EFM) is when the baby’s heart rate is monitored with an ultrasound machine while the mother’s contractions are monitored with a toco (pressure sensor).


The main purpose of fetal monitoring is that it shows a tracing of the baby's heart rate in real time with contractions so we can see how the baby responds to your contractions.


Fetal monitoring records increases (accelerations), decreases (decelerations) in fetal heart rate (FHR) as well as how frequent and long your contractions are. Monitoring may be done all the time during labor (continuous) or broken up intervals (intermittent).


HOW OFTEN/ HOW LONG?

Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN) in the U.S. recommends “initial and ongoing” assessment of EFM tracings.


If you have certain risks you will be more likely to kept continuously on the monitors with nurses required to keep continuous eyes on the tracing. Charting every 15 minutes on the tracing is what most hospitals require to any labor considered "high risk". Labors not considered high risk may be able to have intermitting fetal monitoring, where they are able to be removed from the monitors and aloud to move freely for certain periods of time.


WHAT QUALIFIES AS HIGH RISK:

- Having meconium stained fluid

- Having Pre-Eclampsia or Eclampsia

- Being on Pitocin

- FHR having frequent decelerations

- Any titratable drug (magnesium, insulin, pitocin)

- Having an epidural


Now almost every situation mentioned above will require a mother and baby to be on continuous fetal monitoring throughout labor. Why? Simply because every situation mentioned above has the potential to cause fetal distress.


Types of fetal monitoring:

  1. Internal- FSE (fetal scalp electrode) + IUPC (intrauterine pressure catheter). water must be broken, only used if cervix is not changing to get accurate measurement of strength of contractions. Allow nurse to go up highest amount of Pitocin or if FHR is abnormal internal monitoring gives a more accurate heart rate reading.

  2. Traditional EFM- most common / basic fetal monitoring used in the hospital setting. Cords with straps around belly. Can be restrictive since you are tethered to the monitor on cords, used if patient has an epidural.

  3. Mobile- wireless, waterproof electronic fetal monitors. We call MONICA or Novii. Pad on center of belly. More mobility for someone laboring without an epidural.

  4. Intermittent- doppler or connected to traditional EFM at regular time intervals. Every 15-30 minutes a nurse will doppler the FHR before, during, and after a contraction (about 60 seconds total) to make sure no decelerations are noted. Differs per hospital policy and guidelines. Care provider also palpates contractions noting length, duration, and intensity. This method can also use a special stethoscope. This is the primary method of checking fetal well-being at planned home births and freestanding birth centers. Sometimes this method is not preferred by Doctors due to lack of liability and proper training.

EVIDENCE:

Cochrane researchers combined the results of 12 randomized, controlled trials including more than 37,000 participants. There were no differences between the continuous EFM group and the hands-on listening group in Apgar scores or cord blood gases.

The continuous electronic fetal monitoring group were 63% more likely to have a Cesarean and 15% more likely to experience the use of vacuum or forceps when compared to those in the hands-on listening group.


Alfirevic Z, Devane D, Gyte GM. Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database Syst Rev. 2006 Jul 19;(3):CD006066. doi: 10.1002/14651858.CD006066. Update in: Cochrane Database Syst Rev. 2013;5:CD006066. PMID: 16856111.