Safely lowering the emergency Cesarean and operative vaginal delivery rates using the Fetal Reserve Index

Abstract

Objective: The cardiotocograph (CTG) or electronic fetal monitoring (EFM) was developed to prevent fetal asphyxia and subsequent neurological injury. From a public health perspective, it has failed these objectives while increasing emergency operative deliveries (emergency operative deliveries (EODs) – emergency cesarean delivery or operative vaginal delivery) for newborns, who in retrospect, actually did not require the assistance. EODs increase the risks of complications and stress for patients, families, and medical personnel. A safe reduction in the need for EOD will likely reduce both the overall Cesarean section rate as well as the risk of fetal neurological injury during labor to which it is related. We have developed the fetal reserve index (FRI), which is more comprehensive than CTG as a new screening method for early identification of the fetus at-risk of both neurological harm and the need to “rescue” by means of an EOD. Here, we compare prospectively the need for EOD in two groups of parturients undergoing a trial of labor at term. One group was managed conventionally, the other by the principles of the FRI.

Study design: We compared the need for EOD of 800 parturients with singleton cases undergoing a trial of labor at term entering with normal CTG patterns (ACOG category 1). Patients were either treated routinely (400 – “early cases”) or in a second group seen later actively managed using the principles of the FRI (400 – “late cases”). The FRI includes measurements of five components of the CTG: rate, variability, decelerations, accelerations, and abnormal uterine activity combined with the presence of medical, obstetrical, and fetal risk factors. The 8-point metric categorizes cases as “green”, “yellow”, and “red” with the latter being at risk.

Results: All 800 patients delivered babies, who were discharged in the usual time course with no untoward outcomes noted. The incidence of red zone scores was comparable in the two groups (≈25%), but the use of intrauterine resuscitation (IR) when reaching the red zone in the late group (47%) was more than double the incidence in the early group (20%) (p < .001). Despite (or because of) this, EODs were significantly reduced in the late group, from 17.3 to 4.0% (p < .001). Further, the late group spent less time in the red zone without increasing overall time in labor. Overall, EOD cases averaged >1 h in the red zone versus 0.5 h for non-EODs.

Conclusions: The FRI may provide a metric to reduce EODs and by extension also reduce the risks of both cesarean delivery and adverse fetal/neonatal outcomes. The safe avoidance of EOD would seem to be an important metric to assess the quality of intrapartum management. This study represents the first attempt to apply the principles of the FRI “live” for the concurrent management of patients during labor. These promising results, if confirmed, in larger sample sizes, set the stage for our computerization of the FRI for widespread study. Benefits appear to come from identification and early, conservative management of fetal deterioration before the need to “rescue” the fetus by EOD.

Keywords:

• ACOG monitoring classification system
• cerebral palsy
• electronic fetal monitoring
• fetal reserve index
• intrauterine resuscitation
• neonatal encephalopathy

Disclosure statement

MIE has a US patent (9 131 860 B2) on FRI process and others pending. There was no outside funding of the project and no other relevant conflicts of interest. IRB approval/waiver from the Biomedical Research Association of New York. No potential conflict of interest was reported by the authors.