Incidence of brain injuries in premature infants with gestational age ≤ 34 weeks in ten urban hospitals in China

The Association of Placental Abruption and Pediatric Neurological Outcome: A Systematic Review and Meta-Analysis

Placental histopathology provides insights, or "snapshots", into relevant antenatal factors that could elevate the risk of perinatal brain injury. We present a systematic review and meta-analysis comparing frequencies of adverse neurological outcomes in infants born to women with placental abruption versus without abruption. Records were sourced from MEDLINE, Embase, and the CENTRAL Trials Registry from 1946 to December 2019. Studies followed the PRISMA guidelines and compared frequencies of neurodevelopmental morbidities in infants born to pregnant women with placental abruption (exposure) versus women without placental abruption (comparator). The primary endpoint was cerebral palsy. Periventricular and intraventricular (both severe and any grades of IVH) and any histopathological neuronal damage were the secondary endpoints. Study methodologic quality was assessed by the Ottawa-Newcastle scale. Estimated odds ratios (OR) and hazards ratio (HR) were derived according to study design. Data were meta-analyzed using a random effects model expressed as pooled effect sizes and 95% confidence intervals. We included eight observational studies in the review, including 1245 infants born to women with placental abruption. Results of the random effects meta-analysis show that the odds of infants born to pregnant women with placental abruption who experience cerebral palsy is higher than in infants born to pregnant women without placental abruption (OR 5.71 95% CI (1.17, 27.91); I² = 84.0%). There is no statistical difference in the odds of infants born to pregnant women with placental abruption who experience severe IVH (grade 3+) (OR 1.20 95% CI (0.46, 3.11); I² = 35.8%) and any grade of IVH (OR 1.20 95% CI (0.62, 2.32); I² = 32.3%) vs. women without placental abruption. There is no statistically significant difference in the odds of infants born to pregnant women with placental abruption who experience PVL vs. pregnant women without placental abruption (OR 6.51 95% CI (0.94, 45.16); I² = 0.0%). Despite our meta-analysis suggesting increased odds of cerebral palsy in infants born to pregnant women with placental abruption versus without abruption, this finding should be interpreted cautiously, given high heterogeneity and overall poor quality of the included studies.

Risk factors, trends of neurological disorders, and outcomes of neonatal periventricular hemorrhages

Periventricular hemorrhage is bleeding from the subependymal germinal matrix, which results in severe motor disorders, mental and speech developmental delay.

Purpose. The study aims to evaluate risk factors, the trends of neurological disorders, and the outcomes of neonatal periventricular hemorrhage in children whose mothers were on gravidary anticoagulant and/or antiplatelet therapy.

Material and methods. The study examined 160 newborns with PVH: Group I — 53 (37.9%) children born from pregnancy on the background of antiplatelet and/or anticoagulant therapy for hypercoagulation syndrome; Group II — 87 (62.1%) children born from pregnancy on the background of antiplatelet and/or anticoagulant therapy to treat degree 1A uteroplacental blood flow disorders; Group III — 20 children born from pregnancy without corticosteroids and antiplatelet and/or anticoagulant therapy. All newborns underwent clinical and neurological examination and neurosonography; data on somatic and obstetric anamnesis were obtained from accompanying medical records.

Results. In children of Groups I and II a more severe condition of newborns with periventricular hemorrhage at birth was noted, a slower dynamics of restoration of muscle-postural tone and the pace of psychomotor development were observed compared to children in Group III. In Groups I and II a high incidence of epilepsy (5.7%) and cerebral palsy (6.4%) by 12 months of corrected age was revealed compared with the population.

Conclusion. Gravidary anticoagulant and antiplatelet therapy might be considered as a risk factor for the development of intracranial hemorrhages and severe neurological disorders: epilepsy, cerebral palsy, mental and motor developmental delays. 

Global incidence of intraventricular hemorrhage among extremely preterm infants: a systematic literature review

OBJECTIVES

To conduct a systematic literature review to evaluate the global incidence of intraventricular hemorrhage grade 2-4 among extremely preterm infants.

METHODS

We performed searches in MEDLINE and Embase for intraventricular hemorrhage and prematurity cited in English language observational studies published from May 2006 to October 2017. Included studies analyzed data from infants born at ≤28 weeks' gestational age and reported on intraventricular hemorrhage epidemiology.

RESULTS

Ninety-eight eligible studies encompassed 39 articles from Europe, 31 from North America, 25 from Asia, five from Oceania, and none from Africa or South America; both Europe and North America were included in two publications. The reported global incidence range of intraventricular hemorrhage grade 3-4 was 5-52% (Europe: 5-52%; North America: 8-22%; Asia: 5-36%; Oceania: 8-13%). When only population-based studies were included, the incidence range of intraventricular hemorrhage grade 3-4 was 6-22%. The incidence range of intraventricular hemorrhage grade 2 was infrequently documented and ranged from 5-19% (including population-based studies). The incidence of intraventricular hemorrhage was generally inversely related to gestational age.

CONCLUSIONS

Intraventricular hemorrhage is a frequent complication of extremely preterm birth. Intraventricular hemorrhage incidence range varies by region, and the global incidence of intraventricular hemorrhage grade 2 is not well documented.

Risk Factors for Periventricular Leukomalacia in Preterm Infants: A Systematic Review, Meta-analysis, and GRADE-Based Assessment of Certainty of Evidence

BACKGROUND

We analyzed the certainty of evidence (CoE) for risk factors of periventricular leukomalacia (PVL) in preterm neonates, a common morbidity of prematurity.

METHODS

Medline, CENTRAL, Embase, and CINAHL were searched. Cohort and case-control studies and randomised randomized controlled trials were included. Data extraction was performed in duplicate. A random random-effects meta-analysis was utilizedused. CoE was evaluated as per Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines.

RESULTS

One hundred eighty-six studies evaluating 95 risk factors for PVL were included. Of the 2,509,507 neonates assessed, 16,569 were diagnosed with PVL. Intraventricular hemorrhage [adjusted odds ratio: 3.22 (2.52-4.12)] had moderate CoE for its association with PVL. Other factors such as hypocarbia, chorioamnionitis, PPROM >48 hour, multifetal pregnancy reduction, antenatal indomethacin, lack of antenatal steroids, perinatal asphyxia, ventilation, shock/hypotension, patent ductus arteriosus requiring surgical ligation, late-onset circulatory collapse, sepsis, necrotizing enterocolitis, and neonatal surgery showed significant association with PVL after adjustment for confounders (CoE: very low to low). Amongst the risk factors associated with mother placental fetal (MPF) triad, there was paucity of literature related to genetic predisposition and defective placentation. Sensitivity analysis revealed that the strength of association between invasive ventilation and PVL decreased over time (P < 0.01), suggesting progress in ventilation strategies. Limited studies had evaluated diffuse PVL.

CONCLUSION

Despite decades of research, our findings indicate that the CoE is low to very low for most of the commonly attributed risk factors of PVL. Future studies should evaluate genetic predisposition and defective placentation in the MPF triad contributing to PVL. Studies evaluating exclusively diffuse PVL are warranted.

Mesenchymal stem cell-derived secretomes for therapeutic potential of premature infant diseases

Preterm birth is a complex syndrome and remains a substantial public health problem globally. Its common complications include periventricular leukomalacia (PVL), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP). Despite great advances in the comprehension of the pathogenesis and improvements in neonatal intensive care and associated medicine, preterm birth-related diseases remain essentially without adequate treatment and can lead to high morbidity and mortality. The therapeutic potential of mesenchymal stem/stromal cells (MSCs) appears promising as evidenced by their efficacy in preclinical models of pathologies relevant to premature infant complications. MSC-based therapeutic efficacy is closely associated with MSC secretomes and a subsequent paracrine action response to tissue injuries, which are complex and abundant in response to the local microenvironment. In the current review, we summarize the paracrine mechanisms of MSC secretomes underlying diverse preterm birth-related diseases, including PVL, BPD, NEC and ROP, are summarized, and focus is placed on MSC-conditioned media (CM) and MSC-derived extracellular vesicles (EVs) as key mediators of modulatory action, thereby providing new insights for future therapies in newborn medicine.

A systematic review on brain injury and altered brain development in moderate-late preterm infants

OBJECTIVES

To provide a systematic review of brain injury and altered brain development in moderate-late preterm (MLPT) infants as compared to very preterm and term infants.

STUDY DESIGN

A systematic search in five databases was performed in January 2020. Original research papers on incidence of brain injury and papers using quantitative data on brain development in MLPT infants were selected. The Johanna Briggs Institute 'Critical Appraisal Checklist for Studies Reporting Prevalence Data' was used for quality appraisal. Data extraction included: imaging modality, incidences of brain injury, brain volumes, 2D-measurements and diffusivity values.

RESULTS

In total, 24 studies were eligible. Most studies had a moderate quality. Twenty studies reported on the incidence of brain injury in MLPT infants. The incidence of intraventricular hemorrhage (IVH) ranged from 0.0% to 23.5% and of white matter injury (WMI) from 0.5% to 10.8%. One study reported the incidence of arterial infarction (0.3%) and none of cerebellar hemorrhage. Eleven studies compared incidences of brain injury between MLPT infants and very preterm or term infants. Five studies reported signs of altered brain development in MLPT infants.

CONCLUSIONS

The incidences of IVH and WMI in MLPT infants varied widely between studies. Other abnormalities were sparsely reported. Evidence regarding a higher or lower incidence of brain injury in MLPT infants compared to very preterm or term infants is weak due to moderate methodological quality of reported studies. There is limited evidence suggesting a difference in brain development between MLPT and term infants.

Hypoxia of Rats Subjected to Carotid Artery Ligation Results in Impaired Neurogenesis and Reduced Number of Cortical Neurons

BACKGROUND/AIM

Cerebral ischemia is a major cause of abnormal brain development. In a cerebral ischemia model, periventricular leukomalacia (PVL), white matter lesion and a decrease in the number of subcortical neurons were observed. The aim of this study was to investigate the effect of hypoxia on neurogenesis and cell survival.

MATERIALS AND METHODS

In seven-day postnatal rats, the right carotid artery was ligated. The rats were incubated either in a regular normoxic chamber (control group) or in a hypoxic chamber (PVL group, 8% 02 and 92% N2 at 37°C) for 2 h. Nestin- and NeuN-positive neurons were detected by immunohistochemistry.

RESULTS

The densities of nestin-immunoreactivity (IR) cells in the cerebral parietal cortex and subventricular zone were increased with hypoxia. NeuN-IR cells in the cerebral cortex were significantly decreased in the PVL group.

CONCLUSION

Perinatal white matter injury induced neurogenesis, while the survival of neurons was decreased in the cerebral cortex.

Maternal, Labor, Delivery, and Perinatal Outcomes Associated with Placental Abruption: A Systematic Review

Objective Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. Methods We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. Results A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Conclusion Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.

Recombinant human erythropoietin offers neuroprotection through inducing endogenous erythropoietin receptor and neuroglobin in a neonatal rat model of periventricular white matter damage

Recombinant human erythropoietin (rh-EPO) has been reported to have protective effects against brain injury. The purpose of this study was to evaluate the levels of erythropoietin receptor (EPOR) and neuroglobin (Ngb) in a neonatal rat model of periventricular white matter damage (PWMD), and to identify the relationship between the two proteins. On postnatal day 3 (P3), rats underwent permanent ligation of the right common carotid artery followed by 6% O₂ for 4h (HI) or sham operation and normoxic exposure (sham). Immediately after HI, rats received a single intraperitoneal injection of rh-EPO (5U/g) or saline. We assessed the expression level of Ngb and EPOR on postnatal days 5, 7, 10 and 14. EPOR in the HI rats was initially increased as compared to the sham rats at P5. Subsequently, EPOR expression decreased, but was maintained at a higher level than in sham rats from P7 to P14. In rh-EPO treated rats, the increase in EPOR was greater than in HI rats at P5. However, EPOR levels decreased sharply from P7 to P14. In HI rats, Ngb was increased compared to the sham rats from P5 to P14. Ngb levels were further upregulated after rh-EPO administration from P5 to P10 compared to HI rats. However, this upregulation decreased at P14. In conclusion, this study shows that EPOR and Ngb were upregulated, and both of them act as important coordinated neuroprotectors in rh-EPO treatment of PWMD. However, the two proteins exhibit different expression patterns.

Risk Factors for Intraventricular Hemorrhage in Preterm Infants Born at 34 Weeks of Gestation or Less Following Preterm Premature Rupture of Membranes

OBJECTIVE

The objective of this study is to identify possible perinatal risk factors related to intraventricular hemorrhage (IVH) in preterm infants born at 34 weeks of gestation or less following preterm premature rupture of membranes (pPROM).

METHODS

A total of 292 preterm infants born at 34 weeks of gestation or less following pPROM were enrolled in the study, while 155 newborns with incomplete data, especially those that lack histological examination of the placenta, maternal details, and neonatal characteristics, have been further excluded. Finally, data of 137 preterm infants were included in the analysis. All infants underwent ultrasonographic screening for IVH. Thirty-three infants with IVH were considered as cases and 104 infants without IVH were considered as controls. The association between risk factors and IVH was evaluated by univariate and multivariate logistic regression analyses.

RESULTS

The incidence of IVH in preterm infants born at 34 weeks of gestation or less following pPROM was 24.1%, while the incidence of maternal chorioamnionitis was 43.8%. By univariate analysis, gestational age, birth weight, asphyxia resuscitation, maternal chorioamnionitis, fetal distress, amniotic fluid index, and latency of the rupture of membranes to birth were found to be significantly different between the 2 groups. By logistic regression analysis, lower gestational age, low birth weight, asphyxia resuscitation, and maternal chorioamnionitis were found to be independent risk factors for IVH.

CONCLUSION

Lower gestational age, low birth weight, asphyxia resuscitation, and maternal chorioamnionitis are independent risk factors for IVH in preterm infants born at 34 weeks of gestation or less following pPROM.