Cystic periventricular leukomalacia in preterm infants: an analysis of obstetric risk factors

The Effect of Size and Asymmetry at Birth on Brain Injury and Neurodevelopmental Outcomes in Congenital Heart Disease

Poor and asymmetric fetal growth have been associated with neonatal brain injury (BI) and worse neurodevelopmental outcomes (NDO) in the growth-restricted population due to placental insufficiency. We tested the hypothesis that postnatal markers of fetal growth (birthweight (BW), head circumference (HC), and head to body symmetry) are associated with preoperative white matter injury (WMI) and NDO in infants with single ventricle physiology (SVP) and d-transposition of great arteries (TGA). 173 term newborns (106 TGA; 67 SVP) at two sites had pre-operative brain MRI to assess for WMI and measures of microstructural brain development. NDO was assessed at 30 months with the Bayley Scale of Infant Development-II (n = 69). We tested the association between growth parameters at birth with the primary outcome of WMI on the pre-operative brain MRI. Secondary outcomes included measures of NDO. Newborns with TGA were more likely to have growth asymmetry with smaller heads relative to weight while SVP newborns were symmetrically small. There was no association between BW, HC or asymmetry and WMI on preoperative brain MRI or with measures of microstructural brain development. Similarly, growth parameters at birth were not associated with NDO at 30 months. In a multivariable model only cardiac lesion and site were associated with NDO. Unlike other high-risk infant populations, postnatal markers of fetal growth including head to body asymmetry that is common in TGA is not associated with brain injury or NDO. Lesion type appears to play a more important role in NDO in CHD.

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.

Recurrent neonatal sepsis and progressive white matter injury in a premature newborn culture-positive for group B Streptococcus: A case report

RATIONALE

Group B Streptococcus (GBS) remains a principal pathogen causing neonatal sepsis and meningitis, particularly in premature infants with relatively insufficient immunity. Recurrence may occur uncommonly, largely associated with subclinical mucosal persistence or repetitive exposure to exogenous sources. White matter injury (WMI) including cystic periventricular leukomalacia (PVL) has been associated with intrauterine infection/inflammation, and neonatal infection as a more significant predictor including postnatal sepsis and recurrent infection, even without microbial neuroinvasion. Furthermore, clinical and experimental evidence of WMI by some bacteria other than GBS without central nervous system invasion has been reported. However, there is little evidence of WMI associated with neonatal GBS sepsis in the absence of meningitis in the literature.

PATIENT CONCERNS

A newborn at 30+4 weeks' gestation with low birthweight presented with 2 episodes (with a 13-day interval with no antibiotic therapy) of neonatal sepsis culture-proven for GBS with early-onset presentation after clinical chorioamnionitis via vertical GBS transmission and the associated conditions including prematurity-related neonatal immunodeficiency and persistent mucosal GBS carriage after the first antibiotic treatment. The perinatal GBS infection was complicated by progressive WMI presenting with ventriculomegaly and cystic PVL without a definite evidence of meningitis, intraventricular hemorrhage, and documented cerebral hypoxia or hypoperfusion conditions including septic shock.

DIAGNOSES

Recurrent group B streptococcal sepsis and cystic PVL with ventriculomegaly.

INTERVENTIONS

Two episodes of GBS sepsis were treated with 15-day parenteral antibiotic therapy, respectively.

OUTCOMES

Resolution of the recurrent GBS sepsis without further relapses, however, complicated by WMI and subsequent about 6 months delay in motor development at 12 months' corrected age.

LESSONS

This case suggests WMI associated with GBS bacteremia without central nervous system entry by viable GBS and also shows that in premature infants, intrauterine GBS infection with no interventions may lead to extensive and persistent GBS colonization, early-onset and recurrent GBS disease, and WMI. Postnatal as well as intrauterine infection/inflammation controls with maternal prophylaxis may be pivotal for prevention and limiting the magnitude of neurologic injury.

Epidural analgesia, intrapartum hyperthermia, and neonatal brain injury: a systematic review and meta-analysis

BACKGROUND

Epidural analgesia is associated with intrapartum hyperthermia, and chorioamnionitis is associated with neonatal brain injury. However, it is not known if epidural hyperthermia is associated with neonatal brain injury. This systematic review and meta-analysis investigated three questions: (1) does epidural analgesia cause intrapartum hyperthermia, (2) is intrapartum hyperthermia associated with neonatal brain injury, and (3) is epidural-induced hyperthermia associated with neonatal brain injury?

METHODS

PubMed, ISI Web of Knowledge, The Cochrane Library, and Embase were searched from inception to January 2020 using Medical Subject Headings (MeSH) terms relating to epidural analgesia, hyperthermia, labour, and neonatal brain injury. Studies were reviewed independently for inclusion and quality by two authors (Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach). Two meta-analyses were performed using the Mantel-Haenszel fixed effect method to generate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-one studies were included for Question 1 (646 296 participants), 36 for Question 2 (11 866 021 participants), and two studies for Question 3 (297 113 participants). When the mode of analgesia was randomised, epidural analgesia was associated with intrapartum hyperthermia (OR: 4.21; 95% CI: 3.48-5.09). There was an association between intrapartum hyperthermia and neonatal brain injury (OR: 2.79; 95% CI: 2.54-2.3.06). It was not possible to quantify the association between epidural-induced hyperthermia and neonatal brain injury.

CONCLUSIONS

Epidural analgesia is a cause of intrapartum hyperthermia, and intrapartum hyperthermia of any cause is associated with neonatal brain injury. Further work is required to establish if epidural-induced hyperthermia is a cause of neonatal brain injury.

Spontaneous hypocarbia without mechanical ventilation in preterm infants with cystic periventricular leukomalacia

AIM

Hypocarbia induced by mechanical ventilation has been considered a main cause of cystic periventricular leukomalacia (cPVL). However, hypocarbia may occur spontaneously in response to intracellular metabolic acidosis. We aimed to assess whether hypocarbia is more common during mechanical respiratory support than during spontaneous ventilation in infants with cPVL.

METHOD

In this single-centre, retrospective chart analysis, we compared partial pressure of carbon dioxide (pCO₂ ) during the first 96 hours of life in infants with cPVL during endotracheal mechanical ventilation, non-invasive respiratory support, or without respiratory support.

RESULTS

Cystic periventricular leukomalacia was diagnosed in 23 infants born between 2006 and 2017. Gestational age was 24 weeks in two infants and ranged between 28 and 32 weeks in 21 infants. In these 21 infants, pCO₂ less than 35 mm Hg during the first 96 ours of life accounted for 9/60 (15%) measurements during endotracheal mechanical ventilation, 16/116 (14%) during non-invasive respiratory support and 14/42 (33%) in infants without respiratory support (P = .014).

CONCLUSION

In our series of infants with cPVL, hypocarbia was more common without respiratory support than during endotracheal mechanical ventilation and non-invasive respiratory support. This would suggest that hypocarbia is a symptom rather than a cause of cPVL in these infants.

A population-based study of cystic white matter injury on ultrasound in very preterm infants born over two decades in Nova Scotia, Canada

OBJECTIVE

To identify the temporal trends, risk factors and outcomes of cystic white matter injury (WMI) detected by ultrasound in a population-based cohort of very preterm infants (VPI) with a minimal risk of selection bias.

STUDY DESIGN

All live-born VPIs between 22 and < 31 weeks gestational age born in Nova Scotia, Canada from 1993 to 2013.

RESULTS

Cystic WMI was identified in 87 (7%) out of 1184 eligible infants. The gestational age and mortality adjusted prevalence of cystic WMI decreased over time (p = 0.04). In multivariable analysis, chorioamnionitis, antenatal steroids, admission hypothermia, ventilator support, inotropes, and non-Coagulase-negative Staphylococcal and fungal infections were independently associated with cystic WMI. Cerebral palsy was the most common disability in the survivors, however, half of the survivors had none or mild disability.

CONCLUSIONS

This cohort study demonstrated a decreasing trend in the incidence of cystic WMI and reported population-based neurological outcomes with cystic WMI, which is important for health-care planning and parental counseling.

Association between perinatal hypoxic-ischemia and periventricular leukomalacia in preterm infants: A systematic review and meta-analysis

Background

Although investigators have implicated hypoxic-ischemia (HI) as a potential cause of periventricular leukomalacia (PVL), the role of clinical risk factors or markers for HI in the development of PVL remains controversial. The aim of this study was to identify perinatal HI-related factors associated with PVL.

Method

The PubMed, EMBASE, and Cochrane Library databases were searched. The last search was performed on January 2017. Summary effect estimates (pooled odds ratios [ORs]) were calculated for each risk factor using fixed or random effects models with tests for heterogeneity and publication bias.

Results

Fifteen studies with a total of 12,851 participants were included in this meta-analysis, and 14 potential risk factors were analyzed. The pooled results showed that mothers with oligohydramnios (OR, 1.55; 95% confidence interval [CI], 1.05 to 2.30), preterm infants with acidemia (OR, 1.87; 95% CI, 1.18 to 2.97), 1-minute Apgar score <7 (OR 2.69; 95% CI, 1.13 to 6.41), 5-minute Apgar score <7 (OR, 1.89; 95% CI, 1.39 to 2.56), apnea (OR, 1.76; 95% CI, 1.07 to 2.90), respiratory distress syndrome (OR, 1.46; 95% CI, 1.04 to 2.03), and seizures (OR, 4.60; 95% CI, 2.84 to 7.46) were associated with increased risk of PVL.

Conclusion

This study identified perinatal HI-related risk factors for the development of PVL in preterm infants. Future large-scale prospective clinical studies are required to validate and extend these findings.

White Matter Injury of Prematurity: Its Mechanisms and Clinical Features

A developing central nervous system is vulnerable to various insults such as infection and ischemia. While increased understanding of the dynamic nature of brain development allows a deeper insight into the pathophysiology of perinatal brain injury, the precise nature of specific fetal and neonatal brain injuries and their short- and long-term clinical consequences need special attention and further elucidation. The current review will describe the pathophysiological aspects and clinical significance of white matter injury of prematurity, a main form of perinatal brain injury in premature newborns, with a particular emphasis on its potential antenatal components.

Risk factors for brain damage among preterm twins

AIM

To evaluate the perinatal and postnatal risk factors for various brain pathologies among preterm twins.

METHODS

Retrospective data of 104 twin pairs of which one of the siblings had evidence of abnormal head ultrasound (HUS) and its co-twin with normal HUS served as control.

RESULTS

Abnormal HUS consisted of periventricular echodensities among 69 infants, intraventricular hemorrhage among 28 infants, cystic periventricular leukomalacia among 10 infants, and other parenchymal brain pathologies among 5 infants. Perinatal and postnatal complications were similar between study and controls. Siblings with severe brain pathologies were ventilated for longer time over their co-twins. In 10 out of 11 cases of discordant twins (≥20%) with severe brain pathology, the severe pathology was recorded in the larger sibling.

CONCLUSIONS

Our study results, which included matched preterm twin pairs for study/control groups to evaluate risk factors for the overall evidence of brain injury, could not determine specific risk factors for these brain pathologies. The finding that severe brain pathologies were more common among the larger co-twin requires further study of and attention to short- and long-term outcomes and the potential conflicts that may arise.

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.

Latency after preterm prelabor rupture of the membranes: increased risk for periventricular leukomalacia

Objective. To identify the risk factors for cystic periventricular leukomalacia (cPVL) and their implications for deciding between immediate delivery and conservative management of preterm prelabor rupture of the membranes (pPROM). Methods. The following risk factors were compared between cPVL infants and 6440 controls: chorioamnionitis, sex, gestational age (GA), birth weight, pPROM, and pPROM-delivery interval. Factor impact on cPVL risk and clinical decision-making was determined by multivariate logistic regression. Results. Overall cPVL prevalence (n = 32) was 0.99/1000 births. All cPVL infants but one were born <34 weeks of gestation and were <2500 g; 56% had histological chorioamnionitis versus 1.1% of controls (OR 35.9; 95%-CI 12.6–102.7). Because chorioamnionitis is a postnatal diagnosis, logistic regression was performed with prenatally available factors: pPROM-delivery interval >48 hours (OR 9.0; 95%-CI 4.1–20.0), male gender (OR 3.2; 95%-CI 1.4–7.3). GA was not a risk factor if birth weight was included. Risk decreased with increasing fetal weight despite a prolonged pPROM-delivery interval. Conclusion. pPROM-delivery interval is the single most important prenatally available risk factor for the development of cPVL. Immediate delivery favors babies with chorioamnionitis but disfavors those with non infectious pPROM. In the absence of clinical chorioamnionitis fetal weight gain may offset the inflammatory risk of cPVL caused by a prolonged pPROM-delivery interval.

The fetal inflammatory response syndrome is a risk factor for morbidity in preterm neonates

OBJECTIVE

The aim of this study was to show and discuss an association between fetal inflammatory response syndrome (FIRS) and an adverse neonatal outcome defined as combined severe neonatal morbidity and mortality in preterm neonates hospitalized in our neonatal intensive care unit.

STUDY DESIGN

This was an observational study including all preterm neonates hospitalized in our neonatal intensive care unit over a 21 month period. FIRS was defined as cord blood interleukin (IL)-6 greater than 11 pg/mL. Main outcome parameter was an adverse neonatal outcome defined as hospital mortality and/or the presence of any of 5 prespecified morbidities (bronchopulmonary dysplasia, periventricular leukomalacia, intraventricular hemorrhage, and early- or late-onset sepsis).

RESULTS

Fifty-seven of 176 preterm infants hospitalized during the study period (32%) had an adverse neonatal outcome and 62 of these 176 infants (35%) had FIRS with median IL-6 values of 51.8 pg/mL (range, 11.2 to >1000 pg/mL). In a regression analysis, FIRS was significantly associated with adverse neonatal outcome (P < .001) and with the single outcome parameters, intraventricular hemorrhage and early-onset sepsis (P = .006 and P = .018, respectively). In the bivariate analysis, FIRS was associated with death and bronchopulmonary dysplasia (P = .004 and P < .001, respectively). IL-6 correlated with adverse neonatal outcome (r = 0.411, P < .001). When comparing the correlation in neonates less than 32 weeks' gestational age (r = 0.481, P < .001) with neonates 32 weeks or longer (r = 0.233, P = .019), the difference was nearly significant (P = .065).

CONCLUSION

FIRS is a risk factor for adverse neonatal outcome in preterm infants. In particular, the combination of IL-6 greater than 11 pg/mL and low gestational age increased the risk for severe neonatal morbidity or death.

Cognitive impairment at age 5 years in very preterm infants born following premature rupture of membranes

OBJECTIVE

To evaluate the relationship between preterm premature rupture of membranes (PPROM) and cognitive impairment in 5-year-old children born very preterm.

STUDY DESIGN

The Etude Epidémiologique sur les Petits Ages Gestationnels Study is a population-based cohort of children followed up from birth to age 5 years recruited in 9 French regions in 1997. We analyzed data from singletons born between 24 and 32 weeks gestation categorized into 4 groups according to etiology of prematurity: infants born after PPROM, after idiopathic preterm labor, in a vascular context (Vasc), and to women with other complications (Other). Cognitive development at age 5 years was assessed using the Mental Processing Composite score of the Kaufman-Assessment Battery for Children.

RESULTS

Among the 1051 children followed up to age 5 years, the mean Mental Processing Composite score was 93.6 ± 19.7, and 13.3% of the children (140 of 1051) had cognitive impairment. After adjustment for potential confounders, the risk of cognitive impairment among infants in the PPROM group was not significantly different than that in the idiopathic preterm labor group (OR, 1.09; 95% CI, 0.62-1.92) and the Other group (OR, 1.36; 95% CI, 0.75-2.47), but was lower than that in the Vasc group (OR, 1.86; 95% CI, 1.16-2.97). In the PPROM group, the risk of cognitive impairment was greater when the latency period (ie, time from rupture to delivery) was <3 days (OR, 2.32; 95% CI, 1.07-5.02).

CONCLUSION

Preterm infants born after PPROM are not at increased risk for cognitive impairment in childhood, but the time between PPROM and birth may influence that risk.

Two-year neonatal outcome following PPROM prior to 25 weeks with a prolonged period of oligohydramnios

BACKGROUND

Improved neonatal survival data have been reported following early preterm prelabour rupture of membranes (PPROM) prior to 25 weeks gestation with a prolonged latency to delivery and persistent oligohydramnios. However, data regarding long-term respiratory and neurological morbidity are lacking.

AIMS

To evaluate the respiratory and neurological outcome data at two years of age in a cohort of infants born following PPROM prior to 25 weeks with a prolonged latency (14 days) to delivery and compare the data to an aged matched group of infants.

METHODS

Retrospective case note analysis over a 43-month period at Saint Luc University Hospital, Brussels.

RESULTS

15 surviving infants born following PPROM were matched to a group of 30 control infants. Although there was no significant difference in the incidence of BPD between the groups (33% vs 27%, p=0.24), the length of hospitalisation, duration of respiratory support and number of hospital readmissions for respiratory indications were all significantly higher for infants born following a prolonged period of oligohydramnios. There were no major anomalies on cranial ultrasound in the PPROM group and Baileys developmental assessment at 20-24 months corrected gestational age showed no difference between the two groups (Mental development index 93.9 vs 94.4 and Psychomotor development index 95.5 vs 95.8 respectively p = ns).

CONCLUSION

Neurodevelopmental outcome appears encouraging in this cohort although these infants are at high risk of prolonged initial hospitalisation and significant respiratory morbidity in the first two-years of life.

Episodes of hypocarbia and early-onset sepsis are risk factors for cystic periventricular leukomalacia in the preterm infant

BACKGROUND

Septic episodes in preterm infants recently have been reported to be associated with periventricular leukomalacia (PVL). The role of hypocarbia as an independent risk factor for PVL in clinical studies raises many questions without conclusive answers.

AIMS

To evaluate risk factors for cystic PVL focussing on the influence of hypocarbia.

STUDY DESIGN

Retrospective single centre case-control study.

SUBJECTS

Preterm infants 24 to 35 weeks of gestational age and matched (1:2 for gender, birth year, gestational age and birth weight) controls.

OUTCOME MEASURES

Multivariate analysis of perinatal factors being associated with cystic PVL diagnosed by serial ultrasound examinations.

RESULTS

Univariate analysis of risk factors revealed lower 5 and 10 min Apgar scores, and higher rates of neonatal seizures, early-onset sepsis, neonatal steroids, respiratory distress syndrome with surfactant replacement therapy, and episodes of hypocarbia significantly being associated with PVL. Multivariate analysis using a logistic regression model revealed early-onset sepsis and hypocarbia being significantly associated with PVL (p=.022 and .024, respectively). Lowest PaCO(2) values did not differ as did not the duration of hypocarbia, but the onset of hypocarbia was significantly later in PVL cases compared to controls (mean 26 vs. 15 h, p=.033). Neurodevelopmental follow-up at a median time of 46 months was poor showing 88% of the cases having an adverse neurological outcome.

CONCLUSION

We found early-onset sepsis and episodes of hypocarbia within the first days of life being independently associated with PVL.