Do you remember when KevinMD gave Dr. Amy a chance to guest post about VBAC?
Well, there was another post about VBAC up simultaneously. Its comment section has devolved into an argument about external fetal monitoring and whether it reduces perinatal mortality.
I am subscribed to the comments on this post, and every few days I get an email telling me these two commenters are still arguing about this, and instead of looking up the evidence, they are trading sarcastic insults and puffing up themselves like Doctor Cox on Scrubs. I finally couldn’t take it anymore and replied:
Oh my MAUDE this is not an episode of Scrubs, you two. It is not hard to look up what you two are fighting around. As witty as your banter may be, it doesn’t change the state of the evidence on external fetal monitoring during labor, which isn’t even the point of the original post.
Here is the ACOG practice bulletin on continuous external fetal monitoring. If you can’t access it (you may need to be a member of ACOG), let me sum it up for you.
In the introduction, it says: (emphasis mine)
Despite its widespread use, there is controversy about the efficacy of EFM, interobserver and intraobserver variability, nomenclature, systems for interpretation, and management algorithms. Moreover, there is evidence that the use of EFM increases the rate of cesarean deliveries and operative vaginal deliveries. The purpose of this document is to review nomenclature for fetal heart rate assessment, review the data on the efficacy of EFM, delineate the strengths and shortcomings of EFM, and describe a system for EFM classification.
Here is what they have to say about its efficacy:
” * The use of EFM compared with intermittent auscultation increased the overall cesarean delivery rate (relative risk [RR], 1.66; 95% confidence interval [CI], 1.30–2.13) and the cesarean delivery rate for abnormal FHR or acidosis or both (RR, 2.37; 95% CI, 1.88–3.00).
* The use of EFM increased the risk of both vacuum and forceps operative vaginal delivery (RR, 1.16; 95% CI, 1.01–1.32).
* The use of EFM did not reduce perinatal mortality (RR, 0.85; 95% CI, 0.59–1.23).
* The use of EFM reduced the risk of neonatal seizures (RR, 0.50; 95% CI, 0.31–0.80).
* The use of EFM did not reduce the risk of cerebral palsy (RR, 1.74; 95% CI, 0.97–3.11). “
And, their complete, unedited conclusions:
The following recommendations and conclusions are based on good and consistent scientific evidence (Level A):
* The false-positive rate of EFM for predicting cerebral palsy is high, at greater than 99%.
* The use of EFM is associated with an increased rate of both vacuum and forceps operative vaginal delivery, and cesarean delivery for abnormal FHR patterns or acidosis or both.
* When the FHR tracing includes recurrent variable decelerations, amnioinfusion to relieve umbilical cord compression should be considered.
* Pulse oximetry has not been demonstrated to be a clinically useful test in evaluating fetal status.
The following conclusions are based on limited or inconsistent scientific evidence (Level B):
* There is high interobserver and intraobserver variability in interpretation of FHR tracing.
* Reinterpretation of the FHR tracing, especially if the neonatal outcome is known, may not be reliable.
* The use of EFM does not result in a reduction of cerebral palsy.
The following recommendations are based on expert opinion (Level C):
* A three-tiered system for the categorization of FHR patterns is recommended.
* The labor of women with high-risk conditions should be monitored with continuous FHR monitoring.
* The terms hyperstimulation and hypercontractility should be abandoned.
Not really a glowing recommendation.
Hmm, well, maybe ACOG doesn’t like EFM because it is used to sue physicians. Maybe the Cochrane Database has something on it. Oh, wow, it does!
The unedited conclusions:
Authors’ conclusions: Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The real challenge is how best to convey this uncertainty to women to enable them to make an informed choice without compromising the normality of labour.
Continuous external fetal monitoring, as it is being applied as the most common obstetrical intervention used in birth in the United States, has not been proven to improve neonatal outcomes significantly other than a small reduction in neonatal seizures, which are uncommon and transient. It does free up labor nurses to monitor laboring mothers from a nursing station, and it provides a continuous metric that has a false positive rate of about 99%, and is being used to sue physicians. I am sure it is involved in many more malpractice cases against ob/gyns than a trial of labor for VBAC.
It is amazing to me that it is not condemned with the same vehemence as VBACs. It has definite drawbacks that limit the mother’s autonomy and mobility, and I have never met a woman who thought they were comfortable.
That is one of the reasons I included the use of continuous external fetal monitoring in my research, because I am honestly confused about why some interventions and practices are utilized and supported, while others are not.