I wanted to write up a small, basic overview of some of the options for fetal heart rate and contraction assessment during labor, and some of the advantages and disadvantages of each! This is by no means an in depth assessment, but I wanted to provide you with some quick, helpful information about each so that you know what to expect. For further, more in-depth information on each option, please check out the 3 sites I looked at for reference as I wrote this blog post! Please remember, your unique pregnancy and labor situation may preclude you from intermittent/more portable fetal monitoring options in labor, so it's always important during your prenatal visits to discuss any known risk factors you may have!
1. Handheld Doppler – A handheld ultrasound transducer used for intermittent auscultation of the fetal heart rate and rhythm in prescribed intervals during labor. Can also detect audible accelerations or decelerations of the fetal heart rate. Typically done before, during and after a contraction. Palpation of the abdomen during contractions would be done during this time as well to assess the frequency (described in minutes) intensity (mild, moderate, or strong) and duration, described in seconds.
Advantages: Freedom of maternal movement, typically able to pick up fetal heart rate in many positions the laboring mother may be in.
Disadvantages: Usually only available as an option in hospitals for low-risk mothers on no additional labor stimulating medications/pain relieving meds.
2. Continuous Electronic Fetal Monitoring – An ultrasound transducer is placed on the maternal abdomen and held in place with fabric belts or belly bands for continuous assessment of fetal heart rate, rhythm, and accompanying acceleration/deceleration patterns. Uterine contractions are assessed with the use of a pressure sensor called a tocodynamometer (toco) also held in place with the same belts. The toco is typically placed over the upper abdomen, at the fundus of the uterus. The toco allows for continuous assessment of uterine contraction frequency (described in minutes), duration (described in seconds), and intensity (described as mild, moderate, or strong). A printout (or electronic record) provides providers a fetal heart rate tracing to assess.
Advantages: Allows for continuous assessment of fetal heart rate and contraction pattern, which may be necessary to maintain constant assessment of fetal and maternal safety if giving labor inducing/augmenting medications to mother. Also used with various labor pain medication options such as epidurals and narcotic administration.
Disadvantages: Limits mother’s ability to use more function labor movements. Evidence of varying percentages demonstrates the potential for increased risk of having a cesarean birth or operative delivery.
3. Portable/Wireless Fetal Monitoring – Typically the same set up as a traditional continuous electronic machine set up, but is portable either by being wireless, or by the mother being able to plug into a portable pack that allows her to spend more time out of bed and moving around in greater capacity.
Advantages: Does allow for some portability, not as flexible for mother as handheld doppler use. Mother can remain in more functional (upright/forward leaning positions out of bed). Can be a great alternative to non-portable continuous fetal monitoring options if working as intended.
Disadvantages: May still limit maternal mobility to certain areas of her hospital room or hallways, may slip down on abdomen, depending on maternal positions, and make a continuous fetal monitoring reading difficult to obtain.
4. Internal Fetal Monitoring – A wire electrode known as a fetal scalp electrode (FSE) is placed directly to the fetal scalp and connected to a bedside monitor to obtain a continuous and more accurate assessment of the fetal heart tones. To monitor contractions, a flexible catheter known as an intrauterine pressure catheter (IUPC) is placed inside the uterus, next to the baby, inside the uterine wall, giving an accurate measurement of the frequency, duration and strength of contractions.
Advantages: Can be useful when accurate external fetal monitoring is difficult or impossible to obtain, or when your provider needs to get a better assessment of the fetal response to labor contractions.
Disadvantages: Mother’s membranes must be ruptured for placement. Potential for infection to mother or fetus as these are internally placed monitors. Possibility of injury to fetal scalp. Contraindicated with certain transmissible maternal infections (including HIV, active herpes), and certain conditions of pregnancy (i.e. placenta previa).