A Proposed Evidence-Based Neonatal Work-up to Confirm or Refute Allegations of Intrapartum Asphyxia

Eucapnic pH coupled with arterial cord pH improves hypoxic-ischemic encephalopathy prediction

OBJECTIVE

To consider the classical use of "pH < 7.0 and/or a base deficiency ≥12 mmol/L" as markers of the risk of neonatal hypoxic-ischemic encephalopathy (HIE), recalling various criticisms of the use of these markers in favor of that of neonatal eucapnic pH, which appears to be a better marker of this risk.

METHODS

Fifty-five cases of acidemia with pH < 7.00 were collected from a cohort from the Nice University Hospital with eight cases of HIE. We compared the receiver operating characteristics curves established from the positive likelihood ratio (+LR) for each case of: umbilical cord artery pH (pHa), neonatal eucapnic pH (pH euc-n) in isolation (not matched to pHa), and matched pHa to its own pH euc-n.

RESULTS

The areas under the curve (AUC) are identical for pHa and pH euc-n, but AUC for the matched pair pHa-pH euc-n appears superior but non-significant because of the small number in our cohort. However, using the bootstrap method, the partial AUC for a sensitivity greater than 75% indicates the significant superiority (P < 0.01) of the matched pair pHa-pH euc-n approach.

CONCLUSION

The originality of this study lies in the use of two methodologic approaches: (1) standardized partial analysis of the AUCs of the pHa curve and that of pHa matched to its own pH euc-n, and (2) bootstrap statistical technique, that allowed us to conclude (P < 0.01) that the combined use of pH measured at the cord coupled with its eucapnic correction is better for diagnosing metabolic acidosis and best predicting the risk of HIE.

Neonatal serial creatinine levels as an adjunct biomarker in timing of fetal neurologic injury

Objective

To investigate the rise and clearance of newborn creatinine in perinatal asphyxia as an adjunct biomarker to support or refute allegations of acute intrapartum asphyxia.

Study design

In this retrospective chart review, newborns > 35 weeks gestational age were evaluated from closed medicolegal cases of confirmed perinatal asphyxia and reviewed for causation. Data collected included newborn demographic data, patterns of hypoxic ischemic encephalopathy, brain magnetic resonance imaging, Apgar scores, cord and initial newborn blood gases, and serial newborn creatinine levels during the first 96 h of life. Newborn serum creatinine values were collected at 0-12, 13-24, 25-48, and 49-96 h. Newborn brain magnetic resonance imaging was used to define 3 patterns of asphyxial injury: acute profound, partial prolonged, or Both.

Results

Two hundred and eleven cases of neonatal encephalopathy from multiple institutions were reviewed from 1987 to 2019 with only 76 cases having serial creatinine values during the first 96 h of life. A total of 187 creatinine values were collected. Partial prolonged and Both had significantly greater degree of metabolic acidosis in the first newborn arterial blood gas in comparison to acute profound. Acute profound and Both had significantly lower 5- and 10- minute Apgar scores in comparison to partial prolonged. Newborn creatinine values were stratified by asphyxial injury. Acute profound injury showed minimally elevated creatinine trends with rapid normalization. Partial prolonged and Both demonstrated higher creatinine trends with delayed normalization. Mean creatinine values were significantly different between the three types of asphyxial injuries within 13-24 h of life at the time when creatinine values peaked (p = 0.01).

Conclusion

Serial newborn serum creatinine levels taken within the first 96 h of life can provide objective data of timing and duration of perinatal asphyxia.

FIRS: Neonatal considerations

Fetal Inflammatory Response Syndrome (FIRS) is the fetal counterpart of systemic inflammatory response syndrome (SIRS) described in adults. When the fetus is directly exposed to inflammation of the fetal membranes or the placental-fetal circulation, and organs are adversely affected, the disorder is known as FIRS. This syndrome can significantly affect multiple organs with significant short and long term implications for the newborn. In cases of neonatal encephalopathy when no obvious etiology is identified, FIRS needs to be considered. Based on the significant incidence of chorioamnionitis and its potential effects on the newborn, any evidence of maternal, fetal, or neonatal infection should mandate further evaluation of the placenta and membrane histopathology.

The role of fetal inflammatory response syndrome and fetal anemia in nonpreventable term neonatal encephalopathy

OBJECTIVE

To evaluate asphyxial patterns in term encephalopathic newborns caused by chorioamnionitis or intrapartum blood loss that resulted in cerebral palsy and allegations of obstetrical professional liability.

STUDY DESIGN

As an expert witness, JKM identified term newborns with profound neurologic impairment: 18 born in the presence of chorioamnionitis and 14 with significant anemia.

RESULT

In both study groups, profound depression with low 10-min Apgars was associated with early-onset seizures (88%), multiorgan failure (94%) and a partial prolonged injury to the cortex and subcortical white matter (94%). A cord arterial pH>7.00 was noted in 68% and deep gray matter injury involving the basal ganglia and thalamus occurred in only 19% of the newborns studied.

CONCLUSION

The cord arterial pH and pCO2 values, early-onset seizures and paucity of isolated deep gray matter injury support that significant injury occurred postnatally despite appropriate resuscitation. This unique pattern may refute allegations of obstetrical mismanagement in the intrapartum period.

Neurologic parameters in the perinatal period in children with neurodevelopmental disorders

Cerebral palsy (CP) is a term encompassing a group of nonprogressive, noncontagious conditions causing mild, moderate or severe disorders of neurodevelopment.

OBJECTIVE

Objective of this study was to analyze the possible prenatal etiological factors for the emergence of neurodevelopmental disorders (NDs) and CP from the medical records of 100 children with neuromotor disabilities who were treated in Special Hospital for Children with Neuro-developmental and Movement Disorders, Goljak, Croatia.

RESULTS

ND and CP were more often diagnosed in children with birth weight below 2500 g which was statistically proved at the level of significance reaching 0.05, although significant correlation was low for both parameters reaching 0.21. There are both statistically significant differences and the statistically significant correlation between the three gestational age categories within ND and CP. There were more children with the birth weight below 2500 g in the CP than in the ND group and the difference was statistically significant. In the CP group, there were more children with the lower gestational age than in the ND group, which was statistically highly significant. This difference, together with correlation is significant at the level of 0.01.

CONCLUSION

Further studies on the etiology of NDs are needed, with particular focus on the intrauterine risk factors.

[Cerebral palsy and perinatal asphyxia (II--Medicolegal implications and prevention)]

Obstetric litigation is a growing problem in developed countries and its escalating cost together with increasing medical insurance premiums is a major concern for maternity service providers, leading to obstetric practice cessation by many practitioners. Fifty-four to 74 % of claims are based on cardiotocographic (CTG) abnormalities and their interpretation followed by inappropriate or delayed reactions. A critical analysis is performed about the nine criteria identified by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics in their task force on Neonatal Encephalopathy and Cerebral Palsy: four essential criteria defining neonatal asphyxia and five other suggesting an acute intrapartum event sufficient to cause cerebral palsy in term newborns. The importance of placental histologic examination is emphasized in order to confirm sudden catastrophic events occurring before or during labor or to detect occult thrombotic processes affecting the fetal circulation, patterns of decreased placenta reserve and adaptative responses to chronic hypoxia. It may also exclude intrapartum hypoxia by revealing some histologic patterns typical of acute chorioamnionitis and fetal inflammatory response or compatible with metabolic diseases. Magnetic resonance imaging (MRI) of the infant's damaged brain is very contributive to elucidate the mechanism and timing of asphyxia in conjunction with the clinical picture, by locating cerebral injuries predominantly in white or grey matter. Intrapartum asphyxia is sometimes preventable by delivering weak fetuses by cesarean sections before birth, by avoiding some "sentinel" events, and essentially by responding appropriately to CTG anomalies and performing an efficient neonatal resuscitation. During litigation procedures, it is necessary to have access to a readable CTG, a well-documented partogram, a complete analysis of umbilical cord gases, a placental pathology and an extensive clinical work-up of the newborn infant including cerebral MRI. Malpractice litigation in obstetric care can be reduced by permanent CTG education, respect of national CTG guidelines, use of adjuncts such as fetal blood sampling for pH or lactates, regular review of adverse events in Clinical Risk Management (CRM) groups and periodic audits about low arterial cord pH in newborns, admission to neonatal unit, the need for assisted ventilation and the decision-to-delivery interval for emergency operative deliveries. Considering the fast occurrence of fetal cerebral hypoxic injuries, and thus despite an adequate management, many intrapartum asphyxias will not be preventable. Conversely, well-documented hypoxic-ischemic brain insults during the antenatal period do not automatically exclude intrapartum suboptimal obstetric care.

Does the International Classification of Disease (ICD-9) code accurately identify neonates who clinically have hypoxic-ischemic encephalopathy?

BACKGROUND/AIMS

Hypoxic-ischemic encephalopathy (HIE) refers to neonatal neurological signs and symptoms of hypoxia and/or ischemia. Our aim was to determine the accuracy of ICD-9 codes to identify newborns with HIE confirmed by umbilical cord blood analysis.

METHODS

ICD-9 codes in the newborn chart for birth trauma, birth asphyxia, intrauterine hypoxia, and fetal distress were used to identify newborns with suspected HIE by neonatal personnel. Maternal charts were reviewed for umbilical cord gases meeting the HIE clinical criteria.

RESULTS

There were 21,008 deliveries at center I and 17,540 at center II. ICD-9 codes identified 172 neonates, 49 infants (2.3‰ births) at center I and 123 neonates (7‰) at center II. Only 3 neonates (6%) were ≥34 weeks and none met ACOG criteria [umbilical artery pH <7.00 or base excess (BE) ≥12 mmol/l at center I]. At center II, 80 infants were ≥34 weeks but only 5/123 (4%) met the ACOG clinical criteria for HIE (pH <7.00, BE ≥12 mmol/l, and Apgar ≤3 at 5 min).

CONCLUSIONS

ICD-9 codes are unreliable in identifying birth asphyxia and cannot identify newborns meeting the clinical criteria for intrapartum HIE.