Perinatal Arterial Ischemic Stroke in Fetal Vascular Malperfusion: A Case Series and Literature Review

Neonatal Perforator Stroke: Timing, Risk Factors, and Neurological Outcome from a Single-Center Experience

Background and purpose: Perforator stroke (PS) is a subtype of perinatal arterial ischemic stroke (PAIS), in which injuries occur in the territory of the perforator branches of the main cerebral arteries. This study aims to explore the incidence, timing, risk factors, and clinical presentation of PS in both preterm and full-term neonates. Material and methods: We retrospectively analyzed data about all the neonatal brain MRIs carried out in our hospital from March 2012 to March 2023. Criterium of inclusion was the radiologically confirmed diagnosis of perforator stroke involving one or more arterial districts. Results: A total of 1928 patients underwent brain MRIs during the period considered. PAIS was present in 50 patients, of which 19 had PS (38%). Among the patients with PS, nine were preterm babies (47%), and six suffered from perinatal asphyxia (31.5%). PS cUS diagnosis preceded MRI diagnosis in 88% of preterm babies. The mean age at cUS diagnosis was 20 ± 7 days. Preterm babies were often asymptomatic, whereas term babies showed neurological symptoms (mainly seizures). The outcome was favorable as long as PS was isolated. Conclusions: PS is surprisingly frequent among PAIS. It represents the most common form of PAIS in preterm babies and in babies suffering from birth asphyxia. Prenatal and perinatal factors suggesting a possible thromboembolic etiology leading to PAIS are rare in our population of preterm babies, in which the diagnosis was always preceded by negative cUS. These assumptions suggest a postnatal development of PS in premature babies more than a perinatal one.

Placental and Umbilical Cord Anomalies Detected by Ultrasound as Clinical Risk Factors of Adverse Perinatal Outcomes. Case Series Review of Selected Conditions. Part 3: Vascular Anomalies of the Umbilical Cord and Fetoplacental Vascular Malperfusion

In the previous published reviews Part 1 and Part 2, we examined the association between placental and umbilical cord anomalies in relation to adverse perinatal outcomes. In this conclusive Part 3, only umbilical cord vascular anomalies are considered, together with the perinatal effects caused by maternal vascular malperfusion and the secondary fetal vascular malperfusion anomalies. Specifically, the review comprises the following umbilical cord pathologies: umbilical cord torsion/stricture, amniotic band syndrome and umbilical cord strictures/strangulation, umbilical cord hemorrhagic cyst, umbilical cord rupture/cord hemangioma, umbilical cord hematoma, and umbilical cord ulceration. A series of case presentations and a gallery of images have been included to illustrate this final review.

Frequency and Distribution of Perinatal Arterial Ischemic Stroke in a Cohort of Patients With Cerebral Palsy Using Delayed MRI

PURPOSE

This study examined the occurrence and MRI characteristics of perinatal arterial ischemic stroke (PAIS) in children with cerebral palsy (CP) and suspected term hypoxic-ischemic injury (HII).

METHODS

A retrospective review of brain MRI scans was conducted on children with CP and suspected term HII in South Africa.

RESULTS

Out of 1620 children with CP included in the study, 15 (0.9%) had PAIS. The most common site of infarct was the left middle cerebral artery. The majority of infarcts were unilateral, and 67% of cases exhibited cystic changes. Among children with PAIS, 47% exhibited concurrent HII, with the predominant patterns being basal-ganglia-thalamus (BGT) and watershed (WS). In cases of isolated PAIS (53%), network injuries were prevalent in 88% of children, most commonly involving the posterior limbs of the internal capsule, cerebral peduncles, thalami, and corpus callosum.

CONCLUSIONS

The study highlights that PAIS is a relatively rare condition in children with CP, predominantly occurring in the left middle cerebral artery.

Arterial Ischemic Stroke in Children

Arterial ischemic stroke (AIS) in children has a high mortality and life-long disability rate in surviving patients. Diagnostic delays are longer and risk factors are different compared with AIS in the adult population. Congenital heart disease, cervical arterial dissection, and intracranial arteriopathies are the main causes of AIS in children. New revascularization time windows in children require the definition of diagnostic protocols for stroke in each referral center. In this article, we discuss the neuroimaging techniques and protocols, describe the main underlying causes, and review the current treatment options for pediatric and perinatal AIS.

Development and validation of a nomogram to predict intracranial haemorrhage in neonates

BACKGROUND

The aim of this study was to establish and validate a Susceptibility-weighted imaging (SWI)-based predictive model for neonatal intracranial haemorrhage (ICH).

METHODS

A total of 1190 neonates suspected of ICH after cranial ultrasound screening in a tertiary hospital were retrospectively enrolled. The neonates were randomly divided into a training cohort and a internal validation cohort by a ratio of 7:3. Univariate analysis was used to analyze the correlation between risk factors and ICH, and the prediction model of neonatal ICH was established by multivariate logistic regression based on minimum Akaike information criterion (AIC). The nomogram was externally validated in another tertiary hospital of 91 neonates. The performance of the nomogram was evaluated in terms of discrimination by the area under the curve (AUC), calibration by the calibration curve and clinical net benefit by the decision curve analysis (DCA).

RESULTS

Univariate analysis and min AIC-based multivariate logistic regression screened the following variables to establish a predictive model for neonatal ICH: Platelet count (PLT), gestational diabetes, mode of delivery, amniotic fluid contamination, 1-min Apgar score. The AUC was 0.715, 0.711, and 0.700 for the training cohort, internal validation cohort, and external validation cohort, respectively. The calibration curve showed a good correlation between the nomogram prediction and actual observation for ICH. DCA showed the nomogram was clinically useful.

CONCLUSION

We developed and validated an easy-to-use nomogram to predict ICH for neonates. This model could support individualized risk assessment and healthcare.

Single Umbilical Artery Umbilical Cord Is Associated With High-Grade Distal Fetal Vascular Malperfusion

PURPOSE AND CONTEXT

Umbilical cord abnormalities with clinical signs of cord compromise are frequently associated with fetal vascular malperfusion (FVM). Single umbilical artery (SUA) has been reported to be associated with high-grade FVM in fetal growth restriction but not in an unselected population; our study aimed to address this issue.

METHODS

Clinical and placental phenotypes of 55 consecutive placentas with SUA (Group 1) were compared with those of 655 placentas with 3-vessel umbilical cord (Group 2) from patients who were in the second half of their pregnancy. The placentas were histologically examined using hematoxylin and eosin (H&E) staining and CD 34 immunostaining.

KEY RESULTS

Several umbilical cord phenotypes and high-grade distal FVM, based on H&E staining and endothelial fragmentation by CD34 were significantly more common in Group 1, whereas decidual clusters of multinucleate trophoblasts were more common in Group 2. Notably, H&E staining or CD34 immunostaining evaluated separately showed that high-grade distal FVM was more common in Group 1 than in Group 2, but the difference was not statistically significant.

CONCLUSIONS

SUA predisposes to remote, advanced, and recent high-grade distal villous FVM, with a pathogenesis partly different from that of stasis-induced FVM, likely related to fetal anomalies associated with SUA.

CD34 immunostain increases the sensitivity of placental examination for distal fetal vascular malperfusion in liveborn infants

INTRODUCTION

Placental fetal vascular malperfusion (FVM) is associated with increased perinatal morbidity and mortality. This retrospective observational analysis was performed to compare the impact of large proximal vessel (global) FVM, established/remote distal villous FVM, and recent (acute) FVM diagnosed by clustered endothelial fragmentation by CD34 immunostaining, on clinical and other placental phenotypes.

METHODS

Clinical and placental phenotypes of 581 consecutive high-risk pregnancies with a live birth divided in five groups based on presence and type of FVM were analyzed. CD34 immunostaining was performed on all cases to refine the diagnosis of FVM. The statistical analysis was by ANOVA and Chi square.

RESULTS

FVM was present in 88% of placentas from pregnancies dominated by congenital anomalies. 43% of those had global FVM (partial, large proximal vessel) without distal villous changes, either acute (endothelial fragmentation) or established (avascular villi). Acute distal villous FVM without avascular villi did not link with significant perinatal morbidity/mortality, likely because of its short duration. Established distal villous FVM with active endothelial fragmentation, labelled as FVM with temporal heterogeneity, is associated with preterm births, preeclampsia, abnormal Dopplers, fetal growth restriction, highest cesarean section rate, and high grade FVM, particularly the latter.

DISCUSSION

Lesions of global FVM are common, featuring relatively low sensitivity for perinatal complications. Caution is indicated in assigning significance to isolated lesions such as fetal vascular ectasia, intramural fibrin deposition and stem vessel obliteration. Established and on-going FVM diagnosed by using CD34 immunostain, is much more significant and portends the most complicated perinatal outcomes.

Development and Validation of a Prediction Model for Perinatal Arterial Ischemic Stroke in Term Neonates

IMPORTANCE

Perinatal arterial ischemic stroke (PAIS) is a focal brain injury in term neonates that is identified postnatally but is presumed to occur near the time of birth. Many pregnancy, delivery, and fetal factors have been associated with PAIS, but early risk detection is lacking; thus, targeted treatment and prevention efforts are currently limited.

OBJECTIVE

To develop and validate a diagnostic risk prediction model that uses common clinical factors to predict the probability of PAIS in a term neonate.

DESIGN, SETTING, AND PARTICIPANTS

In this diagnostic study, a prediction model was developed using multivariable logistic regression with registry-based case data collected between January 2003, and March 2020, from the Alberta Perinatal Stroke Project, Canadian Cerebral Palsy Registry, International Pediatric Stroke Study, and Alberta Pregnancy Outcomes and Nutrition study. Criteria for inclusion were term birth and no underlying medical conditions associated with stroke diagnosis. Records with more than 20% missing data were excluded. Variable selection was based on peer-reviewed literature. Data were analyzed in September 2021.

EXPOSURES

Clinical pregnancy, delivery, and neonatal factors associated with PAIS as common data elements across the 4 registries.

MAIN OUTCOMES AND MEASURES

The primary outcome was the discriminative accuracy of the model predicting PAIS, measured by the concordance statistic (C statistic).

RESULTS

Of 2571 term neonates in the initial analysis (527 [20%] case and 2044 [80%] control individuals; gestational age range, 37-42 weeks), 1389 (54%) were male, with a greater proportion of males among cases compared with controls (318 [60%] vs 1071 [52%]). The final model was developed using 1924 neonates, including 321 cases (17%) and 1603 controls (83%), and 9 clinical factors associated with risk of PAIS in term neonates: maternal age, tobacco exposure, recreational drug exposure, preeclampsia, chorioamnionitis, intrapartum maternal fever, emergency cesarean delivery, low 5-minute Apgar score, and male sex. The model demonstrated good discrimination between cases and controls (C statistic, 0.73; 95% CI, 0.69-0.76) and good model fit (Hosmer-Lemeshow P = .20). Internal validation techniques yielded similar C statistics (0.73 [95% CI, 0.69-0.77] with bootstrap resampling, 10-fold cross-validated area under the curve, 0.72 [bootstrap bias-corrected 95% CI, 0.69-0.76]), as did a sensitivity analysis using cases and controls from Alberta, Canada, only (C statistic, 0.71; 95% CI, 0.65-0.77).

CONCLUSIONS AND RELEVANCE

The findings suggest that clinical variables can be used to develop and internally validate a model to predict the risk of PAIS in term neonates, with good predictive performance and strong internal validity. Identifying neonates with a high probability of PAIS who could then be screened for early diagnosis and treatment may be associated with reductions in lifelong morbidity for affected individuals and their families.

What is known about neuroplacentology in fetal growth restriction and in preterm infants: A narrative review of literature

The placenta plays a fundamental role during pregnancy for fetal growth and development. A suboptimal placental function may result in severe consequences during the infant's first years of life. In recent years, a new field known as neuroplacentology has emerged and it focuses on the role of the placenta in fetal and neonatal brain development. Because of the limited data, our aim was to provide a narrative review of the most recent knowledge about the relation between placental lesions and fetal and newborn neurological development. Papers published online from 2000 until February 2022 were taken into consideration and particular attention was given to articles in which placental lesions were related to neonatal morbidity and short-term and long-term neurological outcome. Most research regarding the role of placental lesions in neurodevelopment has been conducted on fetal growth restriction and preterm infants. Principal neurological outcomes investigated were periventricular leukomalacia, intraventricular hemorrhages, neonatal encephalopathy and autism spectrum disorder. No consequences in motor development were found. All the considered studies agree about the crucial role played by placenta in fetal and neonatal neurological development and outcome. However, the causal mechanisms remain largely unknown. Knowledge on the pathophysiological mechanisms and on placenta-related risks for neurological problems may provide clues for early interventions aiming to improve neurological outcomes, especially among pediatricians and child psychiatrists.