A template for defining a causal relationship between acute intrapartum events and cerebral palsy: international consensus statement. International Cerebral Palsy Task Force

Appraising Neonatal Morbidity and Mortality in a Developing Country Categorized by Gestational Age Grouping and Implications for Targeted Interventions

Introduction

Despite the relatively higher neonatal morbidity and mortality in developing countries, there are limited data on the detailed analysis of the burden in Nigeria. With a database of over 14,000 admissions, this study presents a compelling picture of the current trends disaggregated by their gestational age groups. It provides unique opportunities for better-targeted interventions for further reducing newborn mortality in line with SDG 3, Target 3.2.

Methods

This prospective observational study involved newborn babies admitted to the Neonatal Intensive Care Unit of the University of Ilorin Teaching Hospital, Kwara State, Nigeria, between January 2007 and December 2018. The outcome was the neonatal mortality rates. The exposure variables included birth weight, gestational age (preterm versus term), and clinical diagnosis. Frequencies were generated on tables and charts, and the trends or associations were determined.

Results

Of the 14,760 neonates admitted, 9,030 (61.2%) were term babies, 4,847 (32.8%) were preterm babies, and in 792 (5%) of the admissions, the gestational ages could not be determined. Males constituted a higher proportion with 55.9%, and the total number of deaths in the study period was 14.7%. The mortality ratio was highest among babies with a birth weight of less than 1,000 g (38.0%) and gestational age of less than 28 weeks (65.5%). The trend analysis showed that the mortality rate decreased from 17.8 to 13% over the 12 years, p-value < 0.0001. For term babies, mortality decreased by 45%, from 15.7% in 2007 to 8.7% in 2018, while the decline in mortality for preterm babies was 28.4%, from 25.7% in 2007 to 18.4% in 2018. For both categories, p-values were < 0.001. Regarding morbidity in term babies, asphyxia occurred in (1:3), jaundice (1:5), sepsis (1:6), and respiratory disorders (1:6) of admissions. For mortality, asphyxia occurred in (1:2), sepsis (1:5), jaundice (1:8), and respiratory disorders (1:10) of deaths. The leading causes of morbidity among preterm babies were asphyxia (1:4), sepsis (1:5), respiratory disorders (1:9), and jaundice (1.10). For mortality, their contributions were asphyxia (≈1:2); sepsis (1:5); respiratory disorders (1:9), and jaundice (1:10).

Conclusion

There was a marked improvement in neonatal mortality trends. However, severe perinatal asphyxia, sepsis, hyperbilirubinemia, and respiratory disorders were the leading conditions contributing to 75% of the morbidities and mortalities. Measures to further accelerate the reduction in neonatal morbidity and mortality are discussed.

Is late prevention of cerebral palsy in extremely preterm infants plausible?

Preterm birth continues to be associated with neurodevelopmental problems including cerebral palsy. Cystic white matter injury is still the major neuropathology underlying cerebral palsy, affecting 1-3% of preterm infants. Although rates have gradually fallen over time, the pathogenesis and evolution of cystic white matter injury are still poorly understood. Hypoxia-ischemia (HI) remains an important contributor yet there is no established treatment to prevent injury. Clinically, serial ultrasound and magnetic resonance imaging studies typically show delayed development of cystic lesions 2 to 4 weeks after birth. This raises the important and unresolved question as to whether this represents slow evolution of injury occurring around the time of birth, or repeated injury over many weeks after birth. There is increasing evidence that tertiary injury after HI can contribute to impairment of white and grey matter maturation. In the present review, we discuss preclinical evidence that severe, cystic white matter injury can evolve for many weeks after acute HI and is associated with microglia activity. This suggests the intriguing hypothesis that the tertiary phase of injury is not as subtle as often thought and that there may be a window of therapeutic opportunity for one to two weeks after hypoxic-ischemic injury to prevent delayed cystic lesions and so further reduce the risk of cerebral palsy after preterm birth.

Risk factors for cerebral palsy in neonates due to placental abruption

Aim

This study aimed to identify risk factors for the onset of cerebral palsy (CP) in neonates due to placental abruption and investigate their characteristics.

Methods

A retrospective case–control study was conducted using a nationwide registry from Japan. The study population included pregnant women (n = 122) who delivered an infant with CP between 2009 and 2015, where placental abruption was identified as the single cause of CP. The control group consisted of pregnant women with placental abruption, who delivered an infant without CP and were managed from 2013 to 2014. They were randomly identified from the prenatal database of the Japan Society of Obstetrics and Gynecology (JSOG‐DB; n = 1214). Risk factors were investigated using multivariate analysis.

Results

Alcohol consumption (3.38, 2.01–5.68) (odds ratio, 95% confidence interval), smoking during pregnancy (3.50, 1.32–9.25), number of deliveries (1.28, 1.05–1.56), polyhydramnios (5.60, 1.37–22.6), oral administration of ritodrine hydrochloride (2.09, 1.22–3.57) and hypertensive disorders in pregnancy (2.25, 1.27–4.07) were significant risk factors. In contrast, intravenous administration of oxytocin (odds ratio, 95% confidence interval: 0.22, 0.09–0.58) and magnesium sulfate (0.122, 0.02–0.89) attenuated risk.

Conclusion

Alcohol consumption, smoking during pregnancy, number of deliveries, polyhydramnios, oral administration of ritodrine hydrochloride and hypertensive disorders in pregnancy were identified as risk factors for CP following placental abruption. Regarding alcohol consumption and smoking during pregnancy, the results suggest the importance of educational activities targeting pregnant women to increase their awareness of placental abruption.

Intrapartum hypoxia and sexual dimorphism in adverse perinatal outcomes

OBJECTIVES

The aim of this study is to evaluate whether markers of intrapartum hypoxia differ according to sex, and if this could explain the increased risk of adverse perinatal outcomes in males.

STUDY DESIGN

This is a retrospective observational cohort study of non-anomalous, singleton deliveries >36 completed weeks' gestation at a UK teaching hospital over a 4.5 year period. Absent or incomplete cord gas results were excluded and the remaining data were validated according to an established method. The relations between sex and both arterial pH and a composite variable, 'fetal distress' (cases in which operative delivery or caesarean section were undertaken for presumed fetal compromise), were examined using independent samples t-test and Chi-square test. Odds ratios with 95 % confidence intervals were calculated to describe the relation between fetal sex and intermediate-term adverse outcomes. Binary logistic regression was performed to generate odds ratios (with 95 % confidence intervals) adjusted for arterial pH and fetal distress. This was repeated to adjust for labor and induction of labor.

RESULTS

There were eligible 8758 cases, of which 4655 were male and 4103 female, from a total of 39,148 deliveries during the study period. Neonatal unit admission (OR 1.54, 95 % CI; 1.31-1.80), renal impairment (OR 1.63, 95 % CI; 1.15-2.32), neurological impairment (OR 1.73, 95 % CI; 1.06-2.84) and a composite adverse outcome (OR 1.73, 95 % CI; 1.29-2.33) were all more likely in males, even after adjusting for labor and induction of labor, both of which were more likely males. The mean cord arterial pH of males was lower (7.23 vs 7.24, P = 0.019) although they were not more likely to be acidemic with a pH <7.0 (males 43 (0.92 %) vs females 41 (1.00 %), P = 0.717), and males were also more likely to have fetal distress (834 (17.9 %) vs 588 (14.3 %), P = <0.001). Being male remained associated with adverse outcomes despite adjustment for arterial pH and fetal distress.

CONCLUSION

Despite a lower mean cord arterial pH and greater incidence of fetal distress in males, intrapartum hypoxia does not account for their worse neonatal outcomes.

The association of cerebral palsy with birth asphyxia: a definitional quagmire

AIM

The aim of this study was to investigate whether current literature provides a useful body of evidence reflecting the proportion of cerebral palsy (CP) that is attributable to birth asphyxia.

METHOD

We identified 23 studies conducted between 1986 and 2010 that provided data on intrapartum risks of CP.

RESULTS

The proportion of CP with birth asphyxia as a precursor (case exposure rate) varied from less than 3% to over 50% in the 23 studies reviewed. The studies were heterogeneous in many regards, including the definitions for birth asphyxia and the outcome of CP.

INTERPRETATIONS

Current data do not support the belief, widely held in the medical and legal communities, that birth asphyxia can be recognized reliably and specifically, or that much of CP is due to birth asphyxia. The very high case exposure rates linking birth asphyxia to CP can probably be attributed to several factors: the fact that the clinical picture at birth cannot specifically identify birth asphyxia; the definition of CP employed; and confusion of proximal effects - results - with causes. Further research is needed.

Labor augmentation with oxytocin decreases glutathione level

Objective. To compare oxidative stress following spontaneous vaginal delivery with that induced by Oxytocin augmented delivery. Methods. 98 women recruited prior to labor. 57 delivered spontaneously, while 41 received Oxytocin for augmentation of labor. Complicated deliveries and high-risk pregnancies were excluded. Informed consent was documented. Arterial cord blood gases, levels of Hematocrit, Hemoglobin, and Bilirubin were studied. Glutathione (GSH) concentration was measured by a spectroscopic method. Plasma and red blood cell (RBC) levels of Malondialdehyde indicated lipid peroxidation. RBC uptake of phenol red denoted cell penetrability. SPSS data analysis was used. Results. Cord blood GSH was significantly lower in the Oxytocin group (2.3 +/- 0.55 mM versus 2.55 +/- 0.55 mM, P = .01). No differences were found in plasma or RBC levels of MDA or in uptake of Phenol red between the groups. Conclusion. Lower GSH levels following Oxytocin augmentation indicate an oxidative stress, though selected measures of oxidative stress demonstrate no cell damage.

Placental Pathology and Clinical Outcomes in a Cohort of Infants Admitted to a Neonatal Intensive Care Unit

BACKGROUND

Placental pathology predicts persistent neurological impairment, even in normally grown infants. However, few studies have linked placental pathology with neonatal outcomes in a large population.

METHODS

We matched the clinical outcomes of a cohort of neonates admitted to a neonatal intensive care unit (NICU) with placental pathology, where available, and examined (by multivariable logistic regression) the relationship between placental pathologies and these outcomes. The outcomes included neonatal death, necrotizing enterocolitis, and intraventricular hemorrhage > or = grade 3. A forward selection model (10% significance level for entry) was used after adjusting for onfounding factors.

RESULTS

A detailed gross and microscopic pathological report was available for 1296 eligible infants (64%). Specific placental features were associated with specific neonatal outcomes. The Canadian Neonatal Network has previously determined that specific changes in the pattern of neonatal care can alter the incidence and severity of these outcomes. In the placentas from pregnancies delivering small for gestational age infants who were subsequently admitted to NICU, two different patterns of placental pathologies were found, one ischemic and the other inflammatory.

CONCLUSION

Frozen section examination of placentas may facilitate more timely delivery of tailored neonatal therapy.

Fetal hypoxic and ischemic injuries

PURPOSE OF REVIEW

The principles of neonatal neurological protection following intrapartum hypoxia are briefly reviewed. The physiological principles behind the use of cardiotocograph patterns in defining the timing and mechanism of fetal hypoxia and injury are then demonstrated.

RECENT FINDINGS

Fetal neurological injury may result from progressive hypoxemia, acidosis, diminished cardiac output and cerebral ischemia, manifested at birth as low Apgar scores, multisystem compromise, severe acidosis and encephalopathy. More commonly, however, intrapartum injury results from often intermittent, regional ischemia secondary to umbilical cord or head compression resulting in hemorrhage or infarction. Under these circumstances, the amount of umbilical acidosis and neonatal encephalopathy varies and the potential candidate for neuroprotection may escape recognition and timely treatment. Selecting infants likely to benefit from neuroprotection requires information on the timing, duration and mechanism of hypoxia. Neonatal parameters, including low Apgar scores, acidosis, even seizures, lack sensitivity and specificity. Cardiotocograph patterns are capable of determining the duration, mechanism and severity of hypoxia and occasionally, the timing of neurological injury.

SUMMARY

Protecting the newborn from the neurological consequences of intrapartum hypoxia requires critical definition of the mechanism and timing of this exposure. cardiotocograph tracings offer the opportunity to refine the selection of candidates for neonatal rescue.

The CTG and the timing and mechanism of fetal neurological injuries

Defining the relationship between the cardiotocograph (CTG) pattern and subsequent neurological injury is confounded by the requirement that certain clinical and biochemical perinatal findings are essential for relating intrapartum events to subsequent neurological injury. Similarly, the value of CTG analysis in these cases has been compromised by antiquated terminology focused on hypoxia but not neurological behavior. Strong evidence suggests that the evaluation of umbilical artery acidosis, low Apgar score and neonatal encephalopathy are limited in their ability to either include or exclude intrapartum injury. Proper evaluation of the CTG requires that trends and the rapidity of changes in patterns of decelerations are necessary to confidently define the normal-behaving fetus, the hypoxemic but uninjured fetus, the injured but non-hypoxic fetus, and finally to distinguish ischemic events from other forms of hypoxia. A newly defined CTG pattern, the 'conversion' pattern, appears to be a specific marker of ischemic injury and could help to redefine the role of CTG monitoring.

Cerebral palsy registries

Cerebral palsy (CP) registers appear to be appropriate tools for answering questions regarding the prevalence and characteristics of this common childhood disability. Registers are population databases issuing from multiple sources, relying on a clear definition and inclusion and exclusion criteria of CP, and requiring a mix of skills with the collaboration of obstetricians, pediatricians, and epidemiologists. In Europe alone there are 18 different CP registers or population data collections on CP, and collaborative research efforts exist through a European network. Data collection on CP has also been done in Australia (register), the United States (surveys), and Canada (register). Beside monitoring trends, other public health contributions of CP registers might be to reduce the frequency of CP and to improve the quality of life of children with CP. CP registers are useful to clinicians by enabling them to identify subgroups of children requiring specific etiologic investigations, and also to provide more accurate information to the parents of children with CP.

Developmental outcomes of newborn encephalopathy in the term infant

Newborn encephalopathy is a clinically defined condition of abnormal neurological behaviours in the newborn period. Though most cases have their origin in the preconceptional and antepartum period, newborn encephalopathy represents a crucial link between intrapartum events and permanent neurological problems in the child. The birth prevalence of newborn encephalopathy ranges from 1.8 to 7.7 per 1000 term live births according to the definition used and the population to which it is applied. Few studies have investigated the outcomes of newborn encephalopathy other than for cases solely attributed to intrapartum hypoxia. These adverse outcomes range from death to cerebral palsy, intellectual disability, and less severe neurological disabilities such as learning and behavioural problems. Outcomes following newborn encephalopathy may vary from country to country with 9.1% of affected babies dying in the newborn period in Western Australia and 10.1% manifesting cerebral palsy by the age of two. These compare to a case fatality of 30.5% in Kathmandu and a cerebral palsy rate of 14.5% by one year of age. The study by Robertson et al which followed children with hypoxic ischaemic encephalopathy found an incidence of impairment of 16% among survivors assessed at 8 years with 42% requiring school resource room help or special classes. This review emphasises the great need for comprehensive clinical and educational assessment as these infants approach school entry to enable appropriate educational provisions to be made.

The fetal inflammatory response syndrome and cerebral palsy: yet another challenge and dilemma for the obstetrician

There is increasing evidence demonstrating a relationship between intrauterine infection and the development of neonatal intraventricular haemorrhage and periventricular leukomalacia with the subsequent occurrence of cerebral palsy, which is thought to be mediated through the generation of pro-inflammatory cytokines by the fetus. In the light of this relationship, a review of the current management of intrapartum infection and the associated complications of intrauterine infection such as preterm labour and preterm premature rupture of the membranes would seem timely along with the development of potential strategies which might prevent or ameliorate the effects of the fetal inflammatory response syndrome. The suggested changes in the understanding and management of the fetal inflammatory response syndrome provide a challenge and pose a dilemma for the practising obstetrician.