Mid forceps did not cause "compromised babies" - "compromise" caused forceps: an approach toward safely lowering the cesarean delivery rate

Etiology and Ontogeny of Cerebral Palsy: Implications for Practice and Research

Cerebral palsy (CP) has been recognized as a group of neurologic disorders with varying etiologies and ontogenies. While a percentage of CP cases arises during labor, the expanded use of electronic fetal monitoring (EFM) to include prevention of CP has resulted in decades of vastly increased interventions that have not significantly reduced the incidence of CP for infants born at term in the USA. Litigation alleging that poor obstetrical practice caused CP in most of these affected children has led to contentious arguments regarding the actual etiologies of this condition and often resulted in substantial monetary awards for plaintiffs. Recent advances in genetic testing using whole exome sequencing have revealed that at least one-third of CP cases in term infants are genetic in origin and therefore not labor-related. Here, we will present and discuss previous attempts to sort out contributing etiologies and ontogenies of CP, and how these newer diagnostic techniques are rapidly improving our ability to better detect and understand such cases. In light of these developments, we present our vision for an overarching spectrum for proper categorization of CP cases into that the following groups: (1) those begun at conception from genetic causes (nonpreventable); (2) those stemming from adverse antenatal/pre-labor events (possibly preventable with heightened antepartum assessment); (3) Those arising from intrapartum events (potentially preventable by earlier interventions); (4) Those occurring shortly after birth (possibly preventable with closer neonatal monitoring); (5) Those that appear later in the postnatal period from non-labor-related causes such as untreated infections or postnatal intracranial hemorrhages.

Uterine contraction frequency in the last hour of labor: how many contractions are too many?

OBJECTIVE

Increased frequency of uterine contractions is a component in the cluster of causal conditions that can lead to fetal hypoxia and acidosis and increase the risk for neonatal neurologic injury. For most international obstetrical societies, 5 contractions per 10 min averaged over 30 min is considered as the upper limit of normal uterine activity. We hypothesize that it might be safer to adopt an upper limit of 4 contractions per 10 min.

METHODS

We reviewed our 1970's research database containing 475 patients with closely monitored and well-documented labor and neonatal assessments that included cord blood (CB) pH, base excess (BE), and continuous recording of neonatal heart rate (NHR). Using data segregated by the proportion of the last hour before delivery when uterine contraction frequency (UCF) exceeded 4 and 5 contractions per 10 min respectively, we evaluated outcomes (CB BE, pH, Apgar scores at 1 min, the status of NHR at 16 min after birth, and the proportion of births that did not the result from normal spontaneous vaginal deliveries (NSVDs). ANOVA established relationships between UCF cutoffs and these outcomes. Our sample size is sufficiently large to provide the ability of UCF, per se, to accurately detect an alpha region of .05 88% of the time with an effect size of .15.

RESULTS

During the last hour prior to delivery, a UCF cutoff at 4 contractions per 10 min performed better than a UCF cutoff at 5 contractions per 10 min to enable the earlier identification of risks for abnormal outcomes. The longer UCF was increased, the worse were the outcomes that were measured, and the region >4 but ≤5 contractions identifies the beginnings of worsening conditions in a variety of measures of poor outcomes.

CONCLUSION

Lowering the recommended threshold for UCF from 5 to 4 contractions per 10-minute period as averaged over 30 min facilitates earlier detection of potentially compromised fetuses and is also an important contributor to a multicomponent contextualized approach to risk assessment.

Changing Perspectives of Electronic Fetal Monitoring

The delivery of healthy babies is the primary goal of obstetric care. Many technologies have been developed to reduce both maternal and fetal risks for poor outcomes. For 50 years, electronic fetal monitoring (EFM) has been used extensively in labor attempting to prevent a large proportion of neonatal encephalopathy and cerebral palsy. However, even key opinion leaders admit that EFM has mostly failed to achieve this goal. We believe this situation emanates from a fundamental misunderstanding of differences between screening and diagnostic tests, considerable subjectivity and inter-observer variability in EFM interpretation, failure to address the pathophysiology of fetal compromise, and a tunnel vision focus. To address these suboptimal results, several iterations of increasingly sophisticated analyses have intended to improve the situation. We believe that part of the continuing problem is that the focus of EFM has been too narrow ignoring important contextual issues such as maternal, fetal, and obstetrical risk factors, and increased uterine contraction frequency. All of these can significantly impact the application of EFM to intrapartum care. We have recently developed a new clinical approach, the Fetal Reserve Index (FRI), contextualizing EFM interpretation. Our data suggest the FRI is capable of providing higher accuracy and earlier detection of emerging fetal compromise. Over time, artificial intelligence/machine learning approaches will likely improve measurements and interpretation of FHR characteristics and other relevant variables. Such future developments will allow us to develop more comprehensive models that increase the interpretability and utility of interfaces for clinical decision making during the intrapartum period.