Cerebral palsy in term infants: a clinicopathologic analysis of 158 medicolegal case reviews

Preterm birth increases cerebral palsy hazards in children of mothers with chronic hypertension in pregnancy

BACKGROUND

Children of mothers with chronic-hypertension in pregnancy have high rates of preterm-birth (<37 weeks of gestation) and small-for-gestational-age (SGA), both of which are risk factors of cerebral palsy (CP). This study investigated the cumulative risks of CP in children exposed to maternal chronic-hypertension vs. other types of hypertensive-disorders-of-pregnancy (HDP), and whether preterm-birth and SGA potentiate the antenatal impact of chronic-hypertension to increase CP hazards.

METHODS

This population-based cohort study enrolled 1,417,373 mother-child pairs with singleton live births between 2004 and 2011 from the Taiwan Maternal and Child Health Database. A total of 19,457 pairs with HDP were identified and propensity-score-matched with 97,285 normotensive controls. Children were followed up for CP outcome until age 6-13 years. HDP were classified into chronic-hypertension, gestational-hypertension, preeclampsia, and preeclampsia-with-chronic-hypertension. Using the normotensive group as the reference, the associations between chronic-hypertension and CP hazard were assessed with adjusted hazard ratios (HR) and 95% confidence intervals (CI) in Cox proportional hazards regression models, and the effects of preterm-birth and SGA on the associations were examined.

RESULTS

The HDP group had higher rates of CP (0.8%) than the normotensive group (0.5%), particularly the subgroup of preeclampsia-with-chronic-hypertension (1.0%), followed by preeclampsia (0.9%), chronic-hypertension (0.7%) and gestational-hypertension (0.6%). Preterm-birth, but not SGA, exerted moderating effects to increase CP risks in children exposed to maternal chronic-hypertension. Before adjustments, chronic-hypertension alone had no substantial contribution to CP hazard (HR 1.35, 95% CI 1.00-1.83), while preeclampsia alone (1.64, 1.28-2.11) or with superimposed-chronic-hypertension (1.83, 1.16-2.89) had significant effects. After including preterm-birth in the multivariable model, the CP hazard for chronic-hypertension alone rather than other types of HDP was raised and became significant (1.56, 1.15-2.12), and the significance remained after stepwise adjustments in the final model (1.74, 1.16-2.60).

CONCLUSIONS

Preterm-birth might potentiate CP hazards in children of mothers with chronic-hypertension in pregnancy.

Placental fetal vascular malperfusion in congenital diaphragmatic hernia

The success of in-utero or intrapartum treatment for congenital diaphragmatic hernia (CDH) can be impacted by poor placental function; however, this relationship has not yet been studied. To analyze placental histomorphology in CDH, the frequencies of 24 independent clinical and 48 placental phenotypes were compared. Slides from 103 CDH placentas (group 1) and 133 clinical umbilical cord (UC) compromise/anatomical UC abnormality placentas without CDH (group 2) were subjected to hematoxylin/eosin staining and CD34 immunostaining and then examined. CD34 immunostaining was performed to identify clustered distal villi with endothelial fragmentation of recent fetal vascular malperfusion (FVM). Cesarean delivery and ex utero intrapartum treatment were more common in group 1, but group 2 showed a higher frequency of statistically significant increases in other clinical phenotypes. The frequencies of large vessels and distal villous FVMs (clustered endothelial fragmentation by CD34 immunostaining, stromal vascular karyorrhexis, avascular, or mineralized villi) did not differ between the groups, but low-grade distal villous FVMs were statistically significantly more common in group 1 than in group 2, while high-grade distal villous FVMs were significantly more common in group 2 than group 1. Large vessel and distal villous FVMs were manyfold more common in both the CDH and UC compromise groups than in the general population. However, CDH placentas were more likely to show low-grade distal villous FVMs and less likely to show high-grade distal villous FVMs in UC compromise placentas. FVM of CDH may therefore be caused by a similar pathomechanism as that of UC compromise, resulting in impaired placental fetal blood outflow.

First-trimester biomarkers and the risk of cerebral palsy

BACKGROUND

Cerebral palsy (CP) is the most common severe motor disability and a manifestation of early brain damage.

AIMS

To analyze if abnormal levels of first-trimester biomarkers were associated with CP. Furthermore, to investigate their clinical applicability in early predicting of CP.

STUDY DESIGN

Nationwide cohort study.

SUBJECTS

We included 258.057 singleton live births, born during 2008-2013 with completed first-trimester assessments.

OUTCOME MEASURES

Data on beta subunit of human chorionic gonadotropin (beta-hCG), pregnancy-associated plasma protein-A (PAPP-A), nuchal translucency thickness, and biparietal diameter (BPD) were converted to multiple of the medians (MoM). Associations were analyzed by comparing mean and extreme levels between pregnancies with and without CP. All CP diagnoses were validated by trained neuropediatricians. Logistic regression was used to create an early prediction model.

RESULTS

The mean beta-hCG value was significantly lower in pregnancies with CP (0.96MoM [95% CI 0.91-1.02] vs 1.04MoM [1.04-1.04], p = 0.01) and the mean PAPP-A value tended to be lower (0.96MoM [0.91-1.01] vs 1.01MoM [1.00-1.01], p = 0.07). Moreover, fetuses that developed CP more likely had a BPD measurement below the fifth percentile (7.5% vs 5%, p = 0.045). The final prediction model had poor discrimination.

CONCLUSIONS

Pregnancies with CP tend to have lower values of beta-hCG and PAPP-A in the first trimester, however, the associations are mediated differently. Nonetheless, abnormal levels of the most common first-trimester biomarkers only have weak associations with CP; resulting in inadequate predictive abilities when included in an early prediction model.

Placental pathology: Pathways leading to or associated with perinatal brain injury in experimental neurology, special issue: Placental mediated mechanisms of perinatal brain injury

Perinatal brain injury is a multifactorial process. In utero placental physiology plays a major role in neuroprotection and the normal development of the fetal central nervous system. Advances in placental pathology have clarified several specific mechanisms of injury and the histologic lesions most strongly associated with them. This review provides an updated summary of the relevant placental anatomy and physiology, the specific placental pathways leading to brain injury, the revised Amsterdam classification system for placental pathology, and the known associations of specific placental lesions with subtypes of adverse neurologic outcomes.

Resistance to Neuromuscular Blockade by Rocuronium in Surgical Patients with Spastic Cerebral Palsy

Individuals with spastic cerebral palsy (CP) often exhibit altered sensitivities to neuromuscular blocking agents (NMBAs) used for surgical intubation. We assessed usage of the NMBA rocuronium in patients with spastic CP and evaluated potential modifiers of dosing including gross motor function classification system (GMFCS) level, birthweight, gestational age, and the use of anticonvulsant therapy. In a case-control study, surgical patients with spastic CP (n = 64) or with idiopathic or non-neuromuscular conditions (n = 73) were enrolled after informed consent/assent. Patient data, GMFCS level, anticonvulsant use, and rocuronium dosing for intubation and post-intubation neuromuscular blockade were obtained from medical records. Findings reveal participants with CP required more rocuronium per body weight for intubation than controls (1.00 ± 0.08 versus 0.64 ± 0.03 mg/kg; p < 0.0001). Dosing increased with GMFCS level (Spearman's rho = 0.323; p = 0.005), and participants with moderate to severe disability (GMFCS III-V) had elevated rocuronium with (1.21 ± 0.13 mg/kg) or without (0.86 ± 0.09 mg/kg) concurrent anticonvulsant therapy. Children born full-term or with birthweight >2.5 kg in the CP cohort required more rocuronium than preterm and low birthweight counterparts. Individuals with CP exhibited highly varied and significant resistance to neuromuscular blockade with rocuronium that was related to GMFCS and gestational age and weight at birth.

Disorders of placental villous maturation are present in one-third of cases with spontaneous preterm labor

OBJECTIVES

Spontaneous preterm labor is an obstetrical syndrome accounting for approximately 65-70% of preterm births, the latter being the most frequent cause of neonatal death and the second most frequent cause of death in children less than five years of age worldwide. The purpose of this study was to determine and compare to uncomplicated pregnancies (1) the frequency of placental disorders of villous maturation in spontaneous preterm labor; (2) the frequency of other placental morphologic characteristics associated with the preterm labor syndrome; and (3) the distribution of these lesions according to gestational age at delivery and their severity.

METHODS

A case-control study of singleton pregnant women was conducted that included (1) uncomplicated pregnancies (controls, n=944) and (2) pregnancies with spontaneous preterm labor (cases, n=438). All placentas underwent histopathologic examination. Patients with chronic maternal diseases (e.g., chronic hypertension, diabetes mellitus, renal disease, thyroid disease, asthma, autoimmune disease, and coagulopathies), fetal malformations, chromosomal abnormalities, multifetal gestation, preeclampsia, eclampsia, preterm prelabor rupture of the fetal membranes, gestational hypertension, gestational diabetes mellitus, and HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome were excluded from the study.

RESULTS

Compared to the controls, the most prevalent placental lesions among the cases were the disorders of villous maturation (31.8% [106/333] including delayed villous maturation 18.6% [62/333] vs. 1.4% [6/442], q<0.0001, prevalence ratio 13.7; and accelerated villous maturation 13.2% [44/333] vs. 0% [0/442], q<0.001). Other lesions in decreasing order of prevalence included hypercapillarized villi (15.6% [68/435] vs. 3.5% [33/938], q<0.001, prevalence ratio 4.4); nucleated red blood cells (1.1% [5/437] vs. 0% [0/938], q<0.01); chronic inflammatory lesions (47.9% [210/438] vs. 29.9% [282/944], q<0.0001, prevalence ratio 1.6); fetal inflammatory response (30.1% [132/438] vs. 23.2% [219/944], q<0.05, prevalence ratio 1.3); maternal inflammatory response (45.5% [195/438] vs. 36.1% [341/944], q<0.01, prevalence ratio 1.2); and maternal vascular malperfusion (44.5% [195/438] vs. 35.7% [337/944], q<0.01, prevalence ratio 1.2). Accelerated villous maturation did not show gestational age-dependent association with any other placental lesion while delayed villous maturation showed a gestational age-dependent association with acute placental inflammation (q-value=0.005).

CONCLUSIONS

Disorders of villous maturation are present in nearly one-third of the cases of spontaneous preterm labor.

Forensic Analysis of Umbilical and Newborn Blood Gas Values for Infants at Risk of Cerebral Palsy

Cerebral palsy litigation cases account for the highest claims involving obstetricians/gynecologists, a specialty that ranks among the highest liability medical professions. Although epidemiologic studies indicate that only a small proportion of cerebral palsy (10-20%) is due to birth asphyxia, negligent obstetrical care is often alleged to be the etiologic factor, resulting in contentious medical-legal conflicts. Defense and plaintiff expert opinions regarding the etiology and timing of injury are often polarized, as there is a lack of established methodology for analysis. The objective results provided by umbilical cord and newborn acid/base and blood gas values and the established association with the incidence of cerebral palsy provide a basis for the forensic assessment of both the mechanism and timing of fetal neurologic injury. Using established physiologic and biochemical principles, a series of case examples demonstrates how an unbiased expert assessment can aid in both conflict resolution and opportunities for clinical education.

First-trimester maternal serum biomarkers and the risk of cerebral palsy

AIM

To investigate whether combined first-trimester screening (cFTS) biomarkers are associated with cerebral palsy (CP) and to identify CP characteristics associated with abnormal biomarker levels.

METHOD

In this retrospective case-control data linkage study, we matched mothers of 435 singletons with CP from a population register to their cFTS records and selected 10 singleton pregnancy controls per case. We compared mean and abnormal levels (expressed as multiples of the median [MoMs]) of pregnancy-associated plasma protein-A (PAPP-A), beta subunit of human chorionic gonadotrophin (β-hCG), and nuchal translucency between cases and controls and between CP subgroups.

RESULTS

Compared with control pregnancies, CP pregnancies had lower mean levels of PAPP-A (0.95 vs 1.01 MoM, p=0.02) and β-hCG (0.93 vs 0.99 MoM, p=0.02). Biomarker levels in CP pregnancies were 1.8 times more likely to be associated with abnormally low levels of PAPP-A (p<0.01), 1.4 times for β-hCG (p=0.12), and 2.6 times for low PAPP-A and β-hCG together (p=0.04). In cases with CP, an abnormally low PAPP-A level was associated with moderate preterm birth, low Apgar scores, and Gross Motor Function Classification System level V. Low β-hCG was associated with very low birthweight.

INTERPRETATION

Low first-trimester biomarker levels suggest a role for early pregnancy factors in some causal pathways to CP.

WHAT THIS PAPER ADDS

Low first-trimester levels of biomarkers in maternal serum are associated with later cerebral palsy (CP). Early pregnancy factors have potential importance in causal pathways to CP. Causal pathways involving preterm birth, term neonatal encephalopathy, and genetic syndromes may be implicated.

Predictors of High Grade and Other Clinically Significant Placental Findings by Indication for Submission in Singleton Placentas From Term Births

Indications for placental submission are variable. Established guidelines are largely based on expert opinion, and there is a need for more evidence-based criteria. A 10-year database of term placentas was used to evaluate indications significantly associated with placental pathology. Lesions in 5 categories were separated into high- and low-grade subgroups. Two additional high-grade lesions were also evaluated. Indications associated with high-grade placental lesions were chronic monitoring abnormalities, severe preeclampsia, pregestational diabetes, maternal signs of infection, postdates pregnancy, artificial reproductive technology, drug abuse, umbilical cord entanglements, selected gross placental abnormalities, stillbirth, Apgar 5 minutes <6, small-for-gestational age infant, and macrosomia. Indications for which placental findings did not differ from the population as a whole were acute monitoring abnormalities, chronic hypertension, maternal obesity, vaginal bleeding, accessory lobe/multilobed placenta, meconium-stained fluid, single umbilical artery, and borderline large-for-gestational age infant. Other indications for submission were intermediate showing significant or borderline elevations in the prevalence of low- and high-grade lesions combined. We suggest on the basis of this study that guidelines for the submission of singleton term placentas could be modified to exclude cases with clinical indications that lack a significant association with placental lesions.

Uncertainty over implications of placental histopathological findings: A survey of Australian and New Zealand neonatologists

AIM

Placental examination is known to provide useful information following an adverse pregnancy outcome. Despite existing literature and guidelines for placental examination; current workplace practices, attitudes towards the value of placental examination and the knowledge of perinatal clinicians regarding placental lesions of significance are unknown. The aim of the study is to explore the current knowledge of neonatologists and maternal fetal medicine specialists on placental histopathological findings and clinical management based on placental pathology.

METHODS

A total of 280 specialists working in perinatal centres across Australia and New Zealand were invited to complete a 20-question online multiple-choice-based survey addressing work-place placental examination practices, and participant beliefs regarding the utility of histopathological findings and follow-up practices.

RESULTS

A total of 74 neonatologists participated in the survey (28.2% response rate). Maternal fetal medicine specialists were excluded due to low response rate (2%). A total of 100% of respondents believed placental examination provided useful information regarding recent pregnancy and neonatal outcomes. They reported being aware of the presence of protocols for macroscopic examination of, and indications for histopathological examination of the placenta (55.4 and 54.1%, respectively). Nine neonatologists reported a system for actioning abnormal placental reports. There was no consensus amongst neonatologists as to which specific placental lesions held implications for future pregnancy or neonatal outcomes, and how these findings should be followed.

CONCLUSIONS

Our findings show placental examination is valued amongst neonatologists in Australia and New Zealand, but highlights the need for better education regarding the significance and utility of the results and what would be best practice for following up reports.

Placental findings among newborns with hypoxic ischemic encephalopathy

OBJECTIVE

To determine if pre-specified placental abnormalities among newborns with hypoxic-ischemic encephalopathy (HIE) differ compared to newborns admitted to a NICU without encephalopathy.

STUDY DESIGN

Retrospective case-control study of newborns with HIE (2006-2014) and controls matched for birth year, gestational age, weight, and gender. One pathologist reviewed archived placental sections using pre-specified criteria.

RESULTS

Sixty-seven newborns had HIE, 46 had available placentas and were matched with 92 controls. HIE had more maternal vascular malperfusion (46% vs 25%, p = 0.02), fetal vascular malperfusion (13% vs 0%, p < 0.001), and clinical abruption (22% vs 4%, p = 0.001). Controls had more normal placentas (29% vs 7%, p = 0.002), and chorioamnionitis (30% vs 9%, p = 0.005). Pre-specified placental lesions occurred in 87% of HIE and 65% of controls (p = 0.008) and identified >90% of primary diagnoses.

CONCLUSIONS

Pre-specified placental lesions identified nearly all abnormalities in HIE and represented both acute and chronic processes.

CD34 immunostain increases the sensitivity of placental diagnosis of fetal vascular malperfusion in stillbirth

INTRODUCTION

Postmortem regressive placental changes of stillbirth may obscure the pre-existing placental histomorphology. The objective is to find out whether the use of CD34 immunostain can increase the sensitivity of placental examination in the diagnosis of fetal vascular malperfusion (FVM).

METHODS

Twenty six independent clinical and 46 placental variables of 46 placentas from stillbirths were statistically compared to those of 92 placentas from livebirths. One histologically most unremarkable section per case was stained using double E-cadherin/CD34 immunostain (ECCD34). Clusters of avascular/hypovascular chorionic villi on hematoxylin and eosin (H&E) staining system and/or CD34 immunostaining, the latter also including endothelial CD34 positive debris in the villous stroma, were regarded as evidence of FVM.

RESULTS

The gestational age and cesarean section rate were statistically significantly lower and the induction of labor and mild erythroblastosis of fetal blood was higher, but the frequencies of clinical and placental features of umbilical cord compromise were not statistically significant between stillbirths and livebirths, respectively. By using H&E stain, 9 (19.6%) of stillbirths and 30 (32.6%) of livebirths showed clusters of avascular villi on H&E. By CD34, the rates of FVM increased to 23 (50%) and 34 (40%), respectively. The increase was statistically significant for stillbirths only (Chi square = 9.4, p = 0.002). By CD34, new clusters of hypovascular chorionic villi or villi with endothelial fragmentation were found in 23 stillbirth cases (50%) as opposed to livebirths (29 cases, 31.5%)(Chi square = 9.4, p = 0.002).

DISCUSSION

When compared with H&E stain, the CD34 increases sensitivity and/or upgrades FVM in placental examination in stillbirths but not in livebirths.

The placenta

Examination of the placenta provides a unique opportunity to explore and understand the intrauterine environment, as well as providing a record of events that may be associated with adverse pregnancy outcomes, one of the most devastating of which is central nervous system (CNS) injury. A number of placental lesions have been described in association with various forms of neurologic injury. They can be divided into four major categories: sentinel events, inflammatory lesions, vascular lesions, and "biomarker" lesions, which are not themselves causative, but are often found in association with other lesions that are causative. The purpose of this review is to outline these placental lesions and summarize the types of CNS injury that have been described in association with each. Finally, one of the most important of all risk factors for CNS injury is the finding of multiple independent placental lesions. The effects of these lesions may be synergistic, particularly when metachronous, with an earlier lesion leaving the CNS more vulnerable to the effects of a later lesion.

The structure and utility of the placental pathology report

The placenta is one of the most exciting organs. It is dynamic; its morphology and function continuously develop and adjust over its brief life span. It mediates the physiology of two distinct yet highly interconnected individuals. The pathology that develops in the placenta, and the adaptations the placenta undergoes to mitigate this pathology, may influence the later life health of the mother and baby (Circ Res, 116, 2015, 715; Hum Reprod Update, 17, 2011, 397; Nutr Rev 71, 2013, S88; Placenta, 36, 2015, S20). Pathological placenta examination may reveal macroscopic and microscopic patterns that provide valuable information to the obstetricians, neonatologists, and pediatricians caring for the family. The placenta often plays a key role in understanding adverse fetal outcomes such as hypoxic brain injury, cerebral palsy, fetal growth restriction, stillbirth, and neonatal death (Placenta, 35, 2014, 552; Placenta, 52, 2017, 58; Placenta, 30, 2009, 700; Obstet Gynecol, 114, 2009, 809; Clin Perinatol, 33, 2006, 503; Pediatr Dev Pathol, 11, 2008, 456; Arch Pathol Lab Med, 124, 2000, 1785). Moreover, it may help to understand the pathophysiology of pregnancy, improve management of subsequent pregnancies, and assist in medicolegal assessment. Placental pathologic examination may even provide evidence of susceptibility to adult-onset diseases such as diabetes (Pediatr Dev Pathol, 6, 2003, 54; Diabetes Metab, 36, 2010, 682; BJOG, 113, 2006, 1126; Int J Gynaecol Obstet, 104, 2009, S25; Zentralbl Gynakol, 97, 1975, 875). Pathologic examination of the placenta may thus be of tremendous value, particularly for those women experiencing an adverse pregnancy outcome. However, this potential utility may be entirely wasted, if the findings are not communicated in an effective manner to the appropriate clinicians. An optimized, readily understandable report of pathological findings is essential for clinical utility.

Fetal vascular malperfusion, an update

Fetal vascular malperfusion is the most recent term applied to a group of placental lesions indicating reduced or absent perfusion of the villous parenchyma by the fetus. The most common etiology of malperfusion is umbilical cord obstruction leading to stasis, ischemia, and in some cases thrombosis. Other contributing factors may include maternal diabetes, fetal cardiac insufficiency or hyperviscosity, and inherited or acquired thrombophilias. Severe or high grade fetal vascular malperfusion is an important risk factor for adverse pregnancy outcomes including fetal growth restriction, fetal CNS injury, and stillbirth. Overall recurrence risk for subsequent pregnancies is low.

Neonatal Infection in Children With Cerebral Palsy: A Registry-Based Cohort Study

BACKGROUND

The goal of this study was to explore the association between neonatal infection and outcomes in children with cerebral palsy.

METHODS

We conducted a retrospective cohort study using the Canadian CP Registry. Neonatal infection was defined as meeting one of the following criteria: (1) septicemia, (2) septic shock, or (3) administration of antibiotics for ≥10 days. Phenotypic profiles of children with cerebral palsy with and without an antecedent neonatal infection were compared. Subgroup analysis was performed, stratified by gestational age (term versus preterm).

RESULTS

Of the 1229 registry participants, 505 (41.1%) were preterm, and 192 (15.6%) met the criteria for neonatal infection with 29% of preterm children having a neonatal infection compared with 6.5% in term-born children. Children with prior neonatal infection were more likely to have a white matter injury (odds ratio 2.2, 95% confidence interval 1.5 to 3.2), spastic diplegic neurological subtype (odds ratio 1.6, 95% confidence interval 1.1 to 2.3), and sensorineural auditory impairment (odds ratio 2.1, 95% confidence interval 1.4 to 3.3). Among preterm children, neonatal infection was not associated with a difference in phenotypic profile. Term-born children with neonatal infection were more likely to have spastic triplegia or quadriplegia (odds ratio 2.4, 95% confidence interval 1.3 to 4.3), concomitant white matter and cortical injury (odds ratio 4.1, 95% confidence interval 1.6 to 10.3), and more severe gross motor ability (Gross Motor Function Classification System IV to V) (odds ratio 2.6, 95% confidence interval 1.4 to 4.8) compared with preterm children.

CONCLUSIONS

Findings suggest a role of systemic infection on the developing brain in term-born infants, and the possibility to develop targeted therapeutic and preventive strategies to reduce cerebral palsy morbidity.

Fetal Vascular Malperfusion

CONTEXT

- Fetal vascular malperfusion, also known as fetal thrombotic vasculopathy, remains an underrecognized pathologic finding and should be noted during placental evaluation.

OBJECTIVE

- To review histologic findings, gain familiarity with the updated terminology, and to recognize important clinical associations with this entity.

DATA SOURCES

- University of Michigan cases, PubMed search, multiple review articles including recent placental workshop group consensus statement, and selected book chapters.

CONCLUSIONS

- Multiple histologic patterns of fetal vascular malperfusion have been described including thrombosis, avascular villi, villous stromal-vascular karyorrhexis, intramural fibrin thrombi, and stem villous vascular obliteration. Various underlying etiologies can be involved in fetal vascular malperfusion. Cord lesions including abnormal insertion, length, and coiling are important causes. Maternal vascular malperfusion such as preeclampsia, hypercoagulable states, lupus anticoagulant, and sometimes diabetes have been associated with this condition. Fetal cardiac dysfunction/malformations and severe fetal inflammatory response in the setting of ascending intrauterine infection have also been attributed to this important finding. Fetal vascular malperfusion has been implicated in several significant and sometimes devastating clinical associations; these include intrauterine growth restriction, poor perinatal outcome, fetal demise, and neurodevelopmental sequelae. A diagnostic challenge may be encountered in cases with prior intrauterine fetal death, since degenerative changes post demise result in a similar histomorphologic picture. The diffuse versus the focal nature of the lesions may help in the distinction.

Image-Based Modeling of Blood Flow and Oxygen Transfer in Feto-Placental Capillaries

During pregnancy, oxygen diffuses from maternal to fetal blood through villous trees in the placenta. In this paper, we simulate blood flow and oxygen transfer in feto-placental capillaries by converting three-dimensional representations of villous and capillary surfaces, reconstructed from confocal laser scanning microscopy, to finite-element meshes, and calculating values of vascular flow resistance and total oxygen transfer. The relationship between the total oxygen transfer rate and the pressure drop through the capillary is shown to be captured across a wide range of pressure drops by physical scaling laws and an upper bound on the oxygen transfer rate. A regression equation is introduced that can be used to estimate the oxygen transfer in a capillary using the vascular resistance. Two techniques for quantifying the effects of statistical variability, experimental uncertainty and pathological placental structure on the calculated properties are then introduced. First, scaling arguments are used to quantify the sensitivity of the model to uncertainties in the geometry and the parameters. Second, the effects of localized dilations in fetal capillaries are investigated using an idealized axisymmetric model, to quantify the possible effect of pathological placental structure on oxygen transfer. The model predicts how, for a fixed pressure drop through a capillary, oxygen transfer is maximized by an optimal width of the dilation. The results could explain the prevalence of fetal hypoxia in cases of delayed villous maturation, a pathology characterized by a lack of the vasculo-syncytial membranes often seen in conjunction with localized capillary dilations.

Association of coexisting morphological umbilical cord abnormality and clinical cord compromise with hypoxic and thrombotic placental histology

To assess the usefulness and limitations of placental histology when morphological umbilical cord (UC) abnormality coexists with clinical UC compromise, 5634 consecutive placentas were divided into four groups and statistically compared: group 1-182 placentas from pregnancies with clinical features of UC compromise (variable decelerations, UC entanglement, prolapse, or true knot at delivery); group 2-1355 placentas with abnormal UC morphology or insertion; group 3-152 placentas with at least one phenotype from group 1 and one from group 2; group 4-3945 placentas with no clinical or morphological UC-related phenotypes (control group).Differences were analyzed by ANOVA or χ (2). Of 68 phenotypes studied, 13 clinical and 18 placental phenotypes were statistically significant. In group 1, 2 phenotypes were most common (oligohydramnios and abnormal fetal heart rate tracing). In group 2, 6 phenotypes were most common, including 4 clinical (abnormal umbilical artery Dopplers, nonmacerated stillbirth, multiple pregnancy, and fetal growth restriction) and 2 placental. In group 3, 23 phenotypes were most common, including 7 clinical (gestational hypertension, polyhydramnios, induction of labor, cesarean section, macerated stillbirth, congenital malformations, and abnormal 3rd stage of labor) and 16 placental. The existence of clinical signs of UC compromise alone was associated with the absence of pathomorphological placental abnormalities. However, the coexistence of clinical and abnormal morphological UC phenotypes was statistically significantly associated with placental histological signs of decreased fetal blood flow, hypoxia (acute and chronic post uterine), shallow placental implantation, and/or amnion nodosum. Thus, confirmation of clinical UC compromise should not be expected on placental examination if no morphological UC abnormality or abnormal UC insertion has been found.

Early onset preeclampsia and cerebral palsy: a double hit model?

BACKGROUND

Cerebral palsy (CP) is a late sequel of pregnancy, and the role of preeclampsia is debatable.

OBJECTIVE

The aims of this study were to determine the association between preeclampsia and cerebral palsy and to determine the risk factors for the development of cerebral palsy in these patients.

STUDY DESIGN

A retrospective population-based cohort study was designed that included 229,192 singleton pregnancies. The study population was divided into 2 groups: (1) patients with preeclampsia (n = 9749) and (2) normotensive gestations (n = 219,443). Generalized Estimating Equation multiple logistic regression models were performed to study the associations among preeclampsia, small for gestational age, gestational age at delivery, and the risk factors for the development of cerebral palsy in neonates of women with preeclampsia.

RESULTS

The rate of cerebral palsy was double in patients with preeclampsia than in the normotensive group (0.2% vs 0.1%; P = .015); early onset preeclampsia and small for gestational age were independent risk factors for the subsequent development of cerebral palsy (odds ratio, 8.639 [95% confidence interval, 4.269-17.480]; odds ratio, 2.737 [95% confidence interval, 1.937-3.868], respectively). A second model was conducted to determine the risk factors for the development of cerebral palsy in women with preeclampsia. Birth asphyxia, complications of prematurity, and neonatal infectious morbidity, but not small for gestational age or gestational age at delivery, were independent risk factors for the development of cerebral palsy.

CONCLUSION

In a comparison with normal pregnant women, the rate of cerebral palsy is double among patients with preeclampsia, especially those with early-onset disease. Early-onset preeclampsia is an independent risk factor for cerebral palsy. Among women with preeclampsia, the presence of neonatal infectious morbidity, birth asphyxia, and complications of prematurity are independent risk factors for the development of cerebral palsy, which further supports the role of a multi-hit model in the pathogenesis of this syndrome.

"Delayed Villous Maturation" in Placental Reporting: Concordance among Consultant Pediatric Pathologists at a Single Specialist Center

Delayed villous maturation (DVM) has been associated with an increased risk of adverse pregnancy outcome, including stillbirth, in the late third trimester, but there are limited published data. Moreover, it is recognized that the assessment of villous maturation is subjective and hampered by both intraobserver and interobserver variability. This audit aims to assess concordance in the reporting of DVM among pediatric pathologists at a single specialist center to improve reproducibility of this potentially important diagnosis. This is a retrospective review of singleton placentas from pregnancies at 35 weeks gestation or greater submitted for histopathologic examination between June 2013 and December 2013. Placental slides were reviewed independently by 4 pediatric pathologists, blinded to the original report, apart from gestational age; villous maturation was assessed as appropriate, accelerated, or delayed for the stated gestational age. A total of 464 placental histopathology reports were reviewed, of which 164 were greater than 35 weeks gestation; of those, 42 (26%) were originally reported as DVM. Following the audit slide review, 38 cases (23%) were assessed to show DVM by at least 1 pathologist. Consensus, with at least 3 pathologists agreeing to a diagnosis of DVM, was achieved in only 14 cases (9% of all cases reviewed; 37% of all cases called DVM). However, the proportion of overall agreement between 2 of the pathologists was 0.92. Concordance for DVM is poor among pathologists and subject to much interobserver variability. Consistency may be improved by consensus histologic review of all the placentas in which the diagnosis of DVM is being considered and stringent application of the published diagnostic criteria.

The clinical implications of placental diagnoses

The clinical utility of placental pathology is both overestimated and underestimated, and the overall quality of placental pathology reporting, even at major medical centers, is highly variable. Clear benefits of examining placentas include the immediate diagnosis of treatable conditions in both the mother and the infant, clarification of the underlying etiology of adverse pregnancy outcomes, estimation of recurrence risk, and guidance for the management of future pregnancies. In order to realize these benefits and get the most out of their pathology departments, it is critical for clinicians to understand the range and implications of placental lesions. This article will review the nomenclature, diagnostic criteria and pitfalls, and clinical significance of seven common placental disease processes and a handful of other lesions.

Antenatal brain injury in third trimester neonates with severe congenital anomalies: an autopsy study

OBJECTIVE

With advances in therapy, more neonates with severe congenital anomalies are surviving, albeit some with neurologic disorders, possibly related to antenatal low brain blood flow. This autopsy series reports antenatal brain injury in neonates expiring due to severe anomalies, and provides correlation with umbilical cord blood gas and acid-base analysis.

METHODS

We identified autopsies of third trimester neonates expiring shortly following delivery due to severe anomalies or malformations. Brain injury classified as "older" included periventricular leukomalacia, gliosis and karyorrhectic neurons, and "recent" included red neurons and reactive glial changes.

RESULTS

We identified 22 cases (nine term, 13 preterm). 16 (73%) had brain injury, including 11 with older injury. Cord arterial blood was analyzed in 17, and six had pH <7 or base deficit >12 mmol/L. Four out of 5 (80%) neonates with neuronal necrosis compared to two out of 12 (17%) without had a pH <7 or base deficit >12 mmol/L (p = 0.03). Five out of nine (56%) neonates with white matter injury compared to one out of 8 (13%) without had pH <7 or base deficit >12 mmol/L (p = NS).

CONCLUSIONS

Antenatal brain injury is frequent in neonates with severe congenital anomalies. Severely abnormal cord blood analysis results correlate significantly with neuronal necrosis and show a trend toward white matter injury; however, the absence of these abnormal results does not preclude the presence of brain injury.

Patterns of placental pathology in preterm premature rupture of membranes

Inflammation is associated with preterm premature rupture of membranes (PPROM) and adverse neonatal outcomes. Subchorionic thrombi, with or without inflammation, may also be a significant pathological finding in PPROM. Patterns of inflammation and thrombosis may give insight into mechanisms of adverse neonatal outcomes associated with PPROM. To characterize histologic findings of placentas from pregnancies complicated by PPROM at altitude, 44 placentas were evaluated for gross and histological indicators of inflammation and thrombosis. Student's t-test (or Mann-Whitney U-test), χ 2 analysis (or Fisher's exact test), mean square contingency and logistic regression were used when appropriate. The prevalence of histologic acute chorioamnionitis (HCA) was 59%. Fetal-derived inflammation (funisitis and chorionic plate vasculitis) was seen at lower frequency (30% and 45%, respectively) and not always in association with HCA. There was a trend for Hispanic women to have higher odds of funisitis (OR = 5.9; P = 0.05). Subchorionic thrombi were seen in 34% of all placentas. The odds of subchorionic thrombi without HCA was 6.3 times greater that the odds of subchorionic thrombi with HCA (P = 0.02). There was no difference in gestational age or rupture-to-delivery interval, with the presence or absence of inflammatory or thrombotic lesions. These findings suggest that PPROM is caused by or can result in fetal inflammation, placental malperfusion, or both, independent of gestational age or rupture-to-delivery interval; maternal ethnicity and altitude may contribute to these findings. Future studies focused on this constellation of PPROM placental findings, genetic polymorphisms and neonatal outcomes are needed.

Fetal thrombotic vasculopathy is associated with thromboembolic events and adverse perinatal outcome but not with neurologic complications: a retrospective cohort study of 54 cases with a 3-year follow-up of children

OBJECTIVE

to test the hypothesis that placental fetal thrombotic vasculopathy (FTV) is associated with obstetric complications and predisposes the child to unfavorable outcomes.

METHODS

54 placentas with FTV lesions and 100 placentas without FTV lesions were collected over a 5-year period at the Croix-Rousse Pathology Department. Clinical findings including maternal, fetal, neonatal condition and pediatric outcome up to three years were collected for each case and control observation. The statistical analyses were assessed with Wald's chi-square derived from conditional logistic regression modeling.

RESULTS

FTV was associated with a significantly higher frequency of obstetric complications: (pregnancy-induced hypertension (OR 3.620, CI 1.563-8.385), preeclampsia (OR 3.674, CI 1.500-8.998), emergency delivery procedures (OR 3.727, CI 1.477-9.403), cesarean sections (OR 2.684, CI 1.016-7.088)), poor fetal condition (intrauterine growth restriction (IUGR) (OR 5.440, CI 2.007-14.748), nonreassuring fetal heart tracing (OR 6.062, CI 2.280-16.115), difficulties in immediate ex utero adaptation (OR 3.416, CI 1.087-10.732)) and perinatal or early childhood demise (OR 3.043, CI 1.327-6.978). On pathological examination, FTV was associated with marginal cord insertion (OR 3.492, CI 1.350-9.035), cord stricture and hypercoiled cord (OR 3.936, CI 1.209-12.813). Thromboembolic events were significantly more frequent in cases with FTV (OR 2.154, CI 1.032-5.622). Neurological complications within the first 3 years of life were also more frequent in the FTV group compared to the control group, but this association was not statistically significant.

CONCLUSIONS

FTV is associated with maternal complications, pathological findings in the placenta, especially gross cord abnormalities, IUGR, and poor perinatal or early childhood outcome. It may also predispose children to somatic thromboembolic events.

Fault and blame, insults to the perinatal brain may be remote from time of birth

There is a certainty in malpractice cases that neurodevelopmental deficits are caused by preventable events at birth when the onset, nature, and timing of the insult in the antenatal and natal period are unknown. The biggest problem is determining timing. Electronic fetal monitoring is given excessive importance in legal cases. Before assigning fault on events at birth, a better understanding of developmental neurobiology and limitations of the present clinical biomarkers is warranted. The issues of single versus repeated episodes, timing of antenatal insults, pros and cons of legal arguments, interaction of various etiologic and anatomic factors are discussed.

Delayed villous maturation of the placenta: quantitative assessment in different cohorts

Placental villous maturation is maximal in the 3rd trimester, with an abundance of terminal villi. Delayed villous maturation (DVM) of the placenta is associated with chromosomal abnormalities, gestational diabetes, and an adverse outcome. This study compares quantitative assessment of vasculo-syncytial membranes (VSM) in cases of liveborn infants, perinatal deaths, and controls. Cases were selected as follows: (1) liveborn infants with a qualitative diagnosis of DVM (n  =  15); (2) controls matched for gestational age whose placentas did not have DVM (n  =  15); (3) stillbirths (SB)/neonatal deaths (NND) showing DVM (n  =  13); and (4) SB from autopsies in which DVM was felt to be the cause of death (COD) (n  =  12). Vasculo-syncytial membranes were counted in 10 terminal villi in each of 10 consecutive high-power fields on 3 slides. Data analysis was carried out using SPSS. Liveborn cases with DVM showed statistically significantly less VSM than controls (mean 1.01 vs 2.42, P < 0.0001). The SB/NND group also showed significantly less VSM than the control group (mean 0.46 vs 2.42, P < 0.0001) and less than the liveborn DVM group (mean 0.46 vs 1.01, P  =  0.001). The COD group was significantly different from the control group (mean 0.42 vs 2.42, P < 0.0001) and the liveborn DVM group (mean 0.42 vs 1.01, P < 0.0001) but not significantly different from the SB/NND group. There is a quantitative reduction in VSM in cases of DVM compared to controls.

Correlation of Placental Pathology with Perinatal Brain Injury

The purpose of placental pathology is to explain adverse clinical outcomes. One of the most tragic of these outcomes is perinatal brain injury with subsequent neurodisability. Findings in the placenta can play an important role in documenting sentinel events, uncovering clinically silent thromboinflammatory disease processes, revealing developmental alterations in functional reserve, and suggesting alterations in related maternal and fetal physiology. These findings, when integrated with clinical data, provide a plausible explanation for an otherwise unexpected outcome and can be helpful for treating physicians and family members.

Hematologic profile of the fetus with systemic inflammatory response syndrome

OBJECTIVE

The fetal inflammatory response syndrome (FIRS) is associated with impending onset of preterm labor/delivery, microbial invasion of the amniotic cavity and increased perinatal morbidity. FIRS has been defined by an elevated fetal plasma interleukin (IL)-6, a cytokine with potent effects on the differentiation and proliferation of hematopoietic precursors. The objective of this study was to characterize the hematologic profile of fetuses with FIRS.

STUDY DESIGN

Fetal blood sampling was performed in patients with preterm prelabor rupture of membranes and preterm labor with intact membranes (n=152). A fetal plasma IL-6 concentration ≥ 11 pg/mL was used to define FIRS. Hemoglobin concentration, platelet count, total white blood cell (WBC) count, differential count, and nucleated red blood cell (NRBC) count were obtained. Since blood cell count varies with gestational age, the observed values were corrected for fetal age by calculating a ratio between the observed and expected mean value for gestational age.

RESULTS

1) The prevalence of FIRS was 28.9% (44/152); 2) fetuses with FIRS had a higher median corrected WBC and corrected neutrophil count than those without FIRS (WBC: median 1.4, range 0.3-5.6, vs. median 1.1, range 0.4-2.9, P=0.001; neutrophils: median 3.6, range 0.1-57.5, vs. median 1.8, range 0.2-13.9, P<0.001); 3) neutrophilia (defined as a neutrophil count >95th centile of gestational age) was significantly more common in fetuses with FIRS than in those without FIRS (71%, 30/42, vs. 35%, 37/105; P<0.001); 4) more than two-thirds of fetuses with FIRS had neutrophilia, whereas neutropenia was present in only 4.8% (2/42); 5) FIRS was not associated with detectable changes in hemoglobin concentration, platelet, lymphocyte, monocyte, basophil or eosinophil counts; and 6) fetuses with FIRS had a median corrected NRBC count higher than those without FIRS. However, the difference did not reach statistical significance (NRBC median 0.07, range 0-1.3, vs. median 0.04, range 0-2.3, P=0.06).

CONCLUSION

The hematologic profile of the human fetus with FIRS is characterized by significant changes in the total WBC and neutrophil counts. The NRBC count in fetuses with FIRS tends to be higher than fetuses without FIRS.

Eosinophilic/T-cell chorionic vasculitis: a clinicopathologic and immunohistochemical study of 51 cases

We report 51 placentas diagnosed with eosinophilic/T-cell chorionic vasculitis (E/TCV), an unusual form of chorionic vasculitis characterized by an infiltrate composed predominantly of CD3+ T cells and eosinophils. The placentas were all 3rd trimester, with 48 (94.1%) being term. Forty-seven (92.2%) were singleton placentas, and the remaining 4 were twins. The E/TCV was limited to 1 chorionic surface vessel in 40 (78.4%) and involved 50% or less of the vessel circumference in 30 (58.8%) placentas. The inflammation faced the intervillous space in 12 (23.5%) and the amniotic cavity in 8 (15.7%) and had no distinct predominant direction in the remaining 31 (60.8%) placentas. Twelve (25.5%) placentas showed mural thrombi or intramural fibrin in association with the E/TCV. One hundred six term singleton placentas were selected as the control group, and the 47 singleton placentas with E/TCV made up the study group for comparison of demographic and histopathologic features. Villitis of unknown etiology was identified more frequently in study group placentas (20 [42.6%]) compared with control group placentas (14 [13.2%]) (P < 0.001). Vascular changes of fetal vascular thrombo-occlusive disease were identified away from the E/TCV more frequently in study group placentas (8 [17.0%]) compared with control group placentas (4 [3.8%]) (P  =  0.008). There were no significant differences in the frequencies of other placental lesions studied, including acute inflammatory lesions and lesions related to maternal underperfusion. There were no significant differences in maternal age, race, parity, birth weight, allergy history, blood type, or medication use.

[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.

Periventricular leukomalacia and placental histopathologic abnormalities

OBJECTIVE

To estimate whether there are placental histopathologic abnormalities associated with neonatal periventricular leukomalacia (PVL), a major precursor of cerebral palsy.

METHODS

This is a case-control study of 167 neonates born between 23 and 34 weeks of gestation diagnosed with PVL by head ultrasonography within 6 weeks of birth, and 167 control neonates without neurologic morbidity matched by gestational age. Placentas for both case neonates and control neonates were reviewed by two perinatal pathologists who were blinded to neonatal course.

RESULTS

Neonates with PVL were significantly more likely to have positive neonatal blood (28.7%, 16.8%, P=.001) and cerebrospinal fluid (14.4%, 4.8%, P=.007) cultures. The ratio of placental weight to birth weight did not differ between groups, but neonates with PVL had significantly more chronic diffuse capsular deciduitis (20.4%, 10.8%, P=.02) and capsular decidual plasma cells (8.4%, 2.4%, P=.02). Conditional logistic regression adjusting for birth weight and the presence of multiple gestation in the identification of PVL showed a significant increase for diffuse capsular deciduitis (P=.02) and capsular decidual plasma cells (P=.03).

CONCLUSION

Periventricular leukomalacia has a significant but weak association with chronic diffuse capsular deciduitis and the presence of capsular decidual plasma cells, evidence of chronic infection but not histologic acute chorioamnionitis.

LEVEL OF EVIDENCE

II.

Risk factors for cerebral palsy in term birth infants

PURPOSE

The aim of this study was to identify the antenatal, intrapartum and neonatal risk factors in term birth infants for cerebral palsy (CP) among babies in a hospital-based study.

MATERIALS AND METHODS

The medical records of children with cerebral palsy referred to our Pediatric Rehabilitation Department in Bialystok were reviewed. Antenatal, intrapartum, and neonatal events were compared among 213 children with CP and 280 controls in a retrospective study. We studied live births >36 weeks gestation born between January 1, 1990, and December 31, 2005.

RESULTS

Fifty-seven percent of the infants with CP were male. Spastic tetraplegia 78 (36.61%) and spastic hemiplegia 65 (30.51%) were the dominant types of CP. Factors associated with an increased risk of CP identified as antenatal and intrapartum risk factors were pre-eclampsia, abruptio placenta, and placenta previa. Birth asphyxia occurred significantly more often (p<0.001) in children with CP compared to controls. In the neonatal period, respiratory distress syndrome, meningitis and neonatal seizures were associated with an increased incidence of CP.

CONCLUSION

Our findings confirm that several antenatal, intrapartum and neonatal risk factors for CP in term birth infants contribute to the etiology of CP.

Disorders of placental circulation and the fetal brain

Disorders of the placental circulation, including the release of deleterious mediators to the fetus, are important risk factors for central nervous system complications. These disorders result in discrete patterns of placental injury detectable by a thorough placental pathologic examination. Consideration of the location, severity, multiplicity, and timing of these lesions is critical to a full understanding of their significance. Less than 10% of placentas from term infants that later develop cerebral palsy lack any evidence of placental abnormalities potentially related to adverse outcome.