I said "consider" having continuous electronic fetal monitoring because studies at the time agreed that fetal heart rate changes were the most reliable symptom that the scar has given way and was causing problems, but we had no evidence that continuous EFM improved outcomes in VBAC labors. On the other hand, as I wrote in the book, EFM had known adverse effects: Women who have continuous monitoring are more likely to have cesareans and instrumental vaginal deliveries (which increases risk of pelvic floor weakness and injury) without any better outcomes for the baby. The book was published in 1999.

A systematic review of the VBAC research published in 2003 reported on two studies looking at the relationship between EFM and newborn outcomes in VBAC labors. Both studies agreed that fetal heart rate abnormality was the most reliable sign of the scar giving way. One study concluded that delivery within 17 minutes of diagnosis improved outcomes on the grounds that no deaths, asphyxia, or need for resuscitation at delivery occurred in babies born within 17 minutes when the only abnormal symptom was prolonged slowing of the fetal heart (lasting more than 1 minute) whereas three babies required resuscitation and there was one case of asphyxia in infants delivered after 17 minutes. Based on their finding, study authors recommended prompt delivery with a prolonged deceleration to prevent morbidity. (When the prolonged deceleration was preceded by severe late decelerations, severe morbidity occurred before the 17 minute mark.) The reviewers point out that the three cases of resuscitation and ventilation were fine within 24 hours and were discharged in good health. If these cases are removed from consideration, one case of neonatal asphyxia and no deaths remain, and the case of asphyxia occurred at 32 minutes after the first episode of slow fetal heart rate. They also point out that any number of factors can cause temporary slowing of the fetal heart, including as a side-effect of an epidural, from maternal positioning causing low blood pressure, from rapid descent through the birth canal, and during cervical examination. In other words, using an episode of slow fetal heart rate as the sole indicator for urgent cesarean is likely to result in unnecessary surgeries. In contrast to the findings of the first study, the other study failed to find an association between time between diagnosis and delivery and newborn neurologic injury or death.

Here is what I think can be gleaned from this: Continuous monitoring seems to confer some benefit, but not all bad outcomes can be prevented regardless of rapidity of delivery, and there is a strong potential for ending up with unnecessary surgery because an episode of slow fetal heart rate is not specific to the scar opening. To this must be added that random assignment trials of continuous electronic fetal monitoring in nonVBAC labors has shown it increases risk of cesarean surgery and instrumental vaginal delivery. If electronic fetal monitoring were harmless and could accurately identify scar rupture, a strong case could be made for using it in all VBAC labors, but it is not. It might make sense, therefore, to reserve continuous monitoring for those women at higher risk of scar rupture such as women being induced or augmented or who have other than low transverse or low-vertical uterine scars or who have single-layer uterine closure. This policy would limit its use to the women most likely to benefit and minimize the number of women exposed to its harms.

Where this leaves you, I do not know.  As a practical matter, it's hard enough to get a VBAC at all, and I would think it would be well nigh impossible to get a care provider, much less the hospital, to agree to forgo continuous monitoring. I suggest ways to avoid EFM's drawbacks in the EFM chapter. Perhaps some of those will be an acceptable compromise for you. 

-- Henci

Guise JM, McDonagh M, Hashima JN, et al. Vaginal birth after cesarean (VBAC) Report/Technology Assessment No. 71. Rockville, MD: Agency for Healthcare Research and Quality March 2003. Report No.: AHRQ Publication No. 03-E018.