Chorioamnionitis Is a Risk Factor for Intraventricular Hemorrhage in Preterm Infants: A Systematic Review and Meta-Analysis

Risk factors associated with intraventricular hemorrhage in very-low-birth-weight premature infants

PURPOSE

To analyze the association between risk factors and severe intraventricular hemorrhage (grade II-IV) in PNB under 1500 g.

METHODS

Multicenter, retrospective, analytical, case-control study in PNB under 34 weeks and under 1500 g admitted to the NICU.

CASE

PNB with severe intraventricular hemorrhage (grade II-IV). Logistic regression analysis was used to adjust for IVH-associated variables and odds ratios (OR).

RESULTS

A total of 90 PNB files were analyzed, 45 cases and 45 controls. The highest risk factors for severe IVH were lower gestational age (OR 1.3, p < 0.001), perinatal asphyxia (OR 12, p < 0.001), Apgar < 6 at minute 1 and 5 (OR 6.3, p < 0.001).

CONCLUSION

Lower gestational age, birth asphyxia, Apgar score lower of 6, and respiratory-type factors are associated with increased risk for severe IVH.

Prenatal diagnosis of cerebellar hemorrhage: A case report

We report the case of a fetus with a sonographic diagnosis of hyperechogenic cerebellum at 28 weeks' gestation, which was suspected to be of hemorrhagic origin on fetal ultrasound. As an adjunct to ultrasound, fetal MRI can confirm the hemorrhagic origin of hyperechogenic cerebellar lesions, particularly by showing a high signal on T1-weighted images. No etiological factors for fetal hemorrhage were found other than maternal hypertension and aspirin use. Postnatal MRI confirmed the prenatal diagnosis of cerebellar hemorrhage without underlying vascular anomaly.

The histologic fetal inflammatory response and neonatal outcomes: systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the prognostic role of concomitant histological fetal inflammatory response with chorioamnionitis on neonatal outcomes through a systematic review and meta-analysis of existing literature.

DATA SOURCES

The primary search was conducted on October 17, 2021, and it was updated on May 26, 2023, across 4 separate databases (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and Scopus) without using any filters.

STUDY ELIGIBILITY CRITERIA

Observational studies reporting obstetrical and neonatal outcomes of infant-mother dyads with histological chorioamnionitis and histological fetal inflammatory response vs infant-mother dyads with histological chorioamnionitis alone were eligible. Studies that enrolled only preterm neonates, studies on neonates born before 37 weeks of gestation, or studies on neonates with very low birthweight (birthweight <1500 g) were included. The protocol was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42021283448).

METHODS

The records were selected by title, abstract, and full text, and disagreements were resolved by consensus. Random-effect model-based pooled odds ratios with corresponding 95% confidence intervals were calculated for dichotomous outcomes.

RESULTS

Overall, 50 studies were identified. A quantitative analysis of 14 outcomes was performed. Subgroup analysis using the mean gestational age of the studies was performed, and a cutoff of 28 weeks of gestation was implemented. Among neonates with lower gestational ages, early-onset sepsis (pooled odds ratio, 2.23; 95% confidence interval, 1.76-2.84) and bronchopulmonary dysplasia (pooled odds ratio, 1.30; 95% confidence interval, 1.02-1.66) were associated with histological fetal inflammatory response. Our analysis showed that preterm neonates with a concomitant histological fetal inflammatory response are more likely to develop intraventricular hemorrhage (pooled odds ratio, 1.54; 95% confidence interval, 1.18-2.02) and retinopathy of prematurity (pooled odds ratio, 1.37; 95% confidence interval, 1.03-1.82). The odds of clinical chorioamnionitis were almost 3-fold higher among infant-mother dyads with histological fetal inflammatory response than among infant-mother dyads with histological chorioamnionitis alone (pooled odds ratio, 2.99; 95% confidence interval, 1.96-4.55).

CONCLUSION

This study investigated multiple neonatal outcomes and found association in the case of 4 major morbidities: early-onset sepsis, bronchopulmonary dysplasia, intraventricular hemorrhage, and retinopathy of prematurity.

Intrauterine exposure to chorioamnionitis and neuroanatomical alterations at term-equivalent age in preterm infants

PURPOSE

Infants born to mothers with chorioamnionitis (CAM) are at increased risk of developing adverse neurodevelopmental disorders in later life. However, clinical magnetic resonance imaging (MRI) studies examining brain injuries and neuroanatomical alterations attributed to CAM have yielded inconsistent results. We aimed to determine whether exposure to histological CAM in utero leads to brain injuries and alterations in the neuroanatomy of preterm infants using 3.0- Tesla MRI at term-equivalent age.

METHODS

A total of 58 preterm infants born before 34 weeks of gestation at Nagoya University Hospital between 2010 and 2018 were eligible for this study (CAM group, n = 21; non-CAM group, n = 37). Brain injuries and abnormalities were assessed using the Kidokoro Global Brain Abnormality Scoring system. Gray matter, white matter, and subcortical gray matter (thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala, and nucleus accumbens) volumes were evaluated using segmentation tools (SPM12 and Infant FreeSurfer).

RESULTS

The Kidokoro scores for each category and severity in the CAM group were comparable to those observed in the non-CAM group. White matter volume was significantly smaller in the CAM group after adjusting for covariates (postmenstrual age at MRI, infant sex, and gestational age) (p = 0.007), whereas gray matter volume was not significantly different. Multiple linear regression analyses revealed significantly smaller volumes in the bilateral pallidums (right, p = 0.045; left, p = 0.038) and nucleus accumbens (right, p = 0.030; left, p = 0.004) after adjusting for covariates.

CONCLUSIONS

Preterm infants born to mothers with histological CAM showed smaller volumes in white matter, pallidum, and nucleus accumbens at term-equivalent age.

Research Hotspots and Trends in the Diagnosis of Chorioamnionitis: Based on Bibliometric Analysis from 2010 to 2022

OBJECTIVE

 This study aimed to conduct a bibliometric analysis of literature related to the diagnosis of chorioamnionitis (CAM) and to point out the current research progress, hotspots, and development trends of CAM research.

STUDY DESIGN

 Literature on the diagnosis of CAM from the Web of Science Core Collection (WoSCC) between 2010 and 2022 was retrieved. CiteSpace, VOSviewer, and Online Analysis Platform (OALM) were used to draw maps of authors, articles, journals, institutions, countries/regions, and keywords.

RESULTS

 A total of 312 articles were included, and the number of articles gradually increased over the study period. The author with the largest number of articles was Roberto Romero. The institution with the largest number of articles was Wayne State University School of Medicine, and the United States was the country that produced the largest number of articles. Analysis of keywords and outbreak words suggested that future research hotspots and trends may focus on early treatment of CAM and more precise, noninvasive, and more sensitive diagnoses.

CONCLUSION

 In this study, visualization software and data information mining were innovatively used to conduct a bibliometric analysis of articles in the field of CAM diagnosis, and the current status, hotspots, and development of this field were obtained. Future research hotspots may be the precision diagnosis and treatment of CAM.

KEY POINTS

· There is no bibliometric study on CAM diagnosis in the existing literature.. · The prediction of CAM diagnosis is an important topic to improve maternal and infant prognosis.. · Bibliometrics can effectively guide the direction of future research..

Small for Gestational Age Affects Outcomes on Singletons and Inborn Births in Extremely Preterm Infants: A Japanese Cohort Study

OBJECTIVE

 This study aimed to compare the short- and long-term outcomes of extremely preterm small for gestational age (SGA) infants and appropriate for gestational age (AGA) infants in Japan.

STUDY DESIGN

 We retrospectively assessed 434 SGA and 1,716 AGA infants born at 22 to 27 weeks of gestational age (GA) and examined their outcomes on singletons and inborn births between 2003 and 2012. Infants were followed-up for 3 years, and the clinical characteristics and outcomes were compared. Fisher's exact and Student's t-tests were used for independent sample comparison. Logistic regression was used to identify associated factors.

RESULTS

 The prevalence of intraventricular hemorrhage ≥ grade 3 was significantly lower (adjusted odds ratio [aOR]: 0.28; 95% confidence interval [CI]: 0.11 - 0.72), and the prevalence of bronchopulmonary dysplasia at 36 weeks of GA and the need for home oxygen therapy were significantly higher (aOR: 2.20; 95% CI: 1.66 - 2.91 and aOR: 2.46; 95% CI: 1.75-3.47, respectively) in SGA infants than in AGA infants. SGA infants born at 24 to 25 weeks of GA had a significantly higher prevalence of developmental quotient (DQ) < 70 (aOR: 1.73; 95% CI: 1.08 - 2.77). Those born at 26 to 27 weeks of GA showed a significantly higher prevalence of cerebral palsy (CP) and visual impairment (aOR: 2.31; 95% CI: 1.22 - 4.40 and aOR: 2.61; 95% CI: 1.21 - 5.61, respectively).

CONCLUSION

 In SGA infants, birth at 24 to 25 weeks of GA is an independent risk factor for DQ < 70, and birth at 26 to 27 weeks of GA is an independent risk factor for CP and visual impairment. However, we did not consider nutritional and developmental factors, and a longer follow-up would help assess neurodevelopmental outcomes.

KEY POINTS

· SGA is a risk factor for poor outcomes.. · In SGA infants, birth at 25 to 26 weeks is a risk factor for low a DQ.. · In SGA infants, birth at 26 to 27 weeks is a risk factor for CP..

Transferring an extremely premature infant to an extra-uterine life support system: a prospective view on the obstetric procedure

To improve care for extremely premature infants, the development of an extrauterine environment for newborn development is being researched, known as Artificial Placenta and Artificial Womb (APAW) technology. APAW facilitates extended development in a liquid-filled incubator with oxygen and nutrient supply through an oxygenator connected to the umbilical vessels. This setup is intended to provide the optimal environment for further development, allowing further lung maturation by delaying gas exposure to oxygen. This innovative treatment necessitates interventions in obstetric procedures to transfer an infant from the native to an artificial womb, while preventing fetal-to-neonatal transition. In this narrative review we analyze relevant fetal physiology literature, provide an overview of insights from APAW studies, and identify considerations for the obstetric procedure from the native uterus to an APAW system. Lastly, this review provides suggestions to improve sterility, fetal and maternal well-being, and the prevention of neonatal transition.

Development and Validation of a Multivariable Predictive Model for the Risk of Histologic Chorioamnionitis in Patients with Premature Rupture of Membranes in the Late Preterm and Term

Background

This study aimed to develop and validate a model to predict histologic chorioamnionitis (HCA) risk in late preterm and term premature rupture of membranes (PROM) patients using clinical and laboratory parameters.

Methods

We conducted a retrospective study on 116 late preterm and term PROM cases, divided into a training (n=81) and a validation set (n=35). A multivariable logistic regression model was developed using the training set. Performance was assessed via the area under the receiver operating characteristic curve (AUC) and net reclassification index (NRI). Decision curve analysis (DCA) evaluated the model's clinical utility. Additionally, nomograms and a web version of the model were developed.

Results

In the training set, the combined model constructed using maternal BMI, gravidity, amniotic fluid characteristics, and prenatal white blood cell (WBC) count showed significantly higher AUC than WBC alone (0.859 vs 0.710, P=0.010), with improved accuracy and sensitivity. In the validation set, the AUC of the combined model remained higher than that of WBC, but the difference was not statistically significant (0.728 vs 0.584, P=0.173). NRI analysis indicated that the combined model improved the correct classification of HCA by 25.0% (P=0.012) compared to that of WBC alone. DCA demonstrated that the combined model had a higher net benefit than WBC in most cases. The nomograms and web version of the model provided convenient tools for clinicians to predict the risk of HCA.

Conclusion

This study successfully developed and validated a clinically feasible multivariable model to predict the risk of HCA in women with late preterm and term PROM.

Relationship between vaginal microbiota and chorioamnionitis: A prospective cohort study

OBJECTIVE

This study aimed to determine the association between vaginal microbiota and chorioamnionitis and its predictive value.

METHODS

Thirty pregnant women in their third trimester were prospectively recruited. The participants were categorized into three groups based on their clinical manifestations and placental pathology: the clinical chorioamnionitis group (IP group), the asymptomatic histological chorioamnionitis group (CP group), and the healthy control group (CN group). Basic data and medical history were collected from each participant. Vaginal samples were collected before delivery and analyzed using microbial diversity sequencing.

RESULTS

No significant differences were observed in age, body mass index, and education among the groups (P > 0.05). However, the IP group exhibited higher rates of low birth weight (60 % vs 20 % vs 0 %, P = 0.008) and respiratory distress syndrome (50 % vs 20 % vs 0 %, P = 0.003) compared with the CP and CN groups. The Shannon index [2.09 (1.16-3.86) vs 0.84 (0.19-1.11) vs 0.44 (0.25-0.85), P = 0.009] and Simpson index [0.70 (0.41-0.81) vs 0.26 (0.04-0.39) vs 0.11 (0.05-0.29), P = 0.010] in the IP group were higher than those in the CN and CP groups. β diversity analysis indicated that the microbial community structure differed among the three groups, with a 14.1 % variation associated with group differences (P = 0.002). At the genus level, the random forest model revealed that Lactobacillus, Dialister, Prevotella, Ligilactobacillus, and Anaerococcus had Gini indexes higher than 1. Further, linear discriminant analysis (LDA) demonstrated that the abundance of Lactobacillus crispatus in the IP group was lower than in the CN group (LDA >4.0, mean relative abundance 9.19 % vs 54.40 %, P = 0.031). The logistic regression analysis indicated that a decreased abundance of L. crispatus was associated with an increased risk of clinical chorioamnionitis.

CONCLUSIONS

The reduction of L. crispatus and increasing trend of specific anaerobic groups are associated with the onset of chorioamnionitis, suggesting their potential value in chorioamnionitis identification. The vaginal microbiota could serve as a useful biomarker for predicting future disease and tailoring surveillance efforts. Additionally, it may present a viable target for developing prevention and therapeutic strategies.

Germinal matrix hemorrhage induces immune responses, brain injury, and motor impairment in neonatal rats

Germinal matrix hemorrhage (GMH) is a major complication of prematurity that causes secondary brain injury and is associated with long-term neurological disabilities. This study used a postnatal day 5 rat model of GMH to explore immune response, brain injury, and neurobehavioral changes after hemorrhagic injury. The results showed that CD45high/CD11b+ immune cells increased in the brain after GMH and were accompanied by increased macrophage-related chemokine/cytokines and inflammatory mediators. Hematoma formed as early as 2 h after injection of collagenase VII and white matter injury appeared not only in the external capsule and hippocampus, but also in the thalamus. In addition, GMH caused abnormal motor function as revealed by gait analysis, and locomotor hyperactivity in the elevated plus maze, though no other obvious anxiety or recognition/memory function changes were noted when examined by the open field test and novel object recognition test. The animal model used here partially reproduces the GMH-induced brain injury and motor dysfunction seen in human neonates and therefore can be used as a valid tool in experimental studies for the development of effective therapeutic strategies for GMH-induced brain injury.

Artificial placenta technology: History, potential and perception

As presently conceptualised, the artificial placenta (AP) is an experimental life support platform for extremely preterm infants (i.e. 400-600 g; 21-23+6 weeks of gestation) born at the border of viability. It is based around the oxygenation of the periviable fetus using gas-exchangers connected to the fetal vasculature. In this system, the lung remains fluid-filled and the fetus remains in a quiescent state. The AP has been in development for some sixty years. Over this time, animal experimental models have evolved iteratively from employing external pump-driven systems used to support comparatively mature fetuses (generally goats or sheep) to platforms driven by the fetal heart and used successfully to maintain extremely premature fetuses weighing around 600 g. Simultaneously, sizable advances in neonatal and obstetric care mean that the nature of a potential candidate patient for this therapy, and thus the threshold success level for justifying its adoption, have both changed markedly since this approach was first conceived. Five landmark breakthroughs have occurred over the developmental history of the AP: i) the first human studies reported in the 1950's; ii) foundation animal studies reported in the 1960's; iii) the first extended use of AP technology combined with fetal pulmonary resuscitation reported in the 1990s; iv) the development of AP systems powered by the fetal heart reported in the 2000's; and v) the adaption of this technology to maintain extremely preterm fetuses (i.e. 500-600 g body weight) reported in the 2010's. Using this framework, the present paper will provide a review of the developmental history of this long-running experimental system and up-to-date assessment of the published field today. With the apparent acceleration of AP technology towards clinical application, there has been an increase in the attention paid to the field, along with some inaccurate commentary regarding its potential application and merits. Additionally, this paper will address several misrepresentations regarding the potential application of AP technology that serve to distract from the significant potential of this approach to greatly improve outcomes for extremely preterm infants born at or close to the present border of viability.

Association between Endotype of Prematurity and Mortality: A Systematic Review, Meta-Analysis, and Meta-Regression

INTRODUCTION

Preterm birth represents the leading cause of neonatal mortality. Pathophysiological pathways, or endotypes, leading to prematurity can be clustered into infection/inflammation and dysfunctional placentation. We aimed to perform a systematic review and meta-analysis exploring the association between these endotypes and risk of mortality during first hospital admission Methods: PROSPERO ID: CRD42020184843. PubMed and Embase were searched for observational studies examining infants with gestational age (GA) ≤34 weeks. Chorioamnionitis represented the infectious-inflammatory endotype, while dysfunctional placentation proxies were hypertensive disorders of pregnancy (HDP) and small for GA (SGA)/intrauterine growth restriction (IUGR). A random-effects model was used to calculate odds ratios (ORs) and 95% confidence intervals. Heterogeneity was studied using random-effects meta-regression analysis.

RESULTS

Of 4,322 potentially relevant studies, 150 (612,580 infants) were included. Meta-analysis showed positive mortality odds for chorioamnionitis (OR: 1.43, 95% confidence interval: 1.25-1.62) and SGA/IUGR (OR: 1.68, 95% confidence interval: 1.38-2.04) but negative mortality odds for HDP (OR 0.74, 95% confidence interval: 0.64-0.86). Chorioamnionitis was associated with a lower GA, while HDP and SGA/IUGR were associated with a higher GA. Meta-regression showed a significant correlation between these differences in GA and mortality odds.

CONCLUSION

Our data suggest that the infectious/inflammatory endotype of prematurity has a greater overall impact on mortality risk as it is the most frequent endotype in the lower GAs. However, when the endotype of placental dysfunction is severe enough to induce growth restriction, it is strongly associated with higher mortality rates even though newborns are more mature.

Three-dimensional cranial ultrasound and functional near-infrared spectroscopy for bedside monitoring of intraventricular hemorrhage in preterm neonates

Germinal Matrix-Intraventricular Hemorrhage (GMH-IVH) remains a significant cause of adverse neurodevelopment in preterm infants. Current management relies on 2-dimensional cranial ultrasound (2D cUS) ventricular measurements. Reliable biomarkers are needed to aid in the early detection of posthemorrhagic ventricular dilatation (PHVD) and subsequent neurodevelopment. In a prospective cohort study, we incorporated 3-dimensional (3D) cUS and functional near-infrared spectroscopy (fNIRS) to monitor neonates with GMH-IVH. Preterm neonates (≤ 32 weeks' gestation) were enrolled following a GMH-IVH diagnosis. Neonates underwent sequential measurements: 3D cUS images were manually segmented using in-house software, and the ventricle volumes (VV) were extracted. Multichannel fNIRS data were acquired using a high-density system, and spontaneous functional connectivity (sFC) was calculated. Of the 30 neonates enrolled in the study, 19 (63.3%) had grade I-II and 11 (36.7%) grade III-IV GMH-IVH; of these, 7 neonates (23%) underwent surgical interventions to divert cerebrospinal fluid (CSF). In infants with severe GMH-IVH, larger VV were significantly associated with decreased |sFC|. Our findings of increased VV and reduced sFC suggest that regional disruptions of ventricular size may impact the development of the underlying white matter. Hence, 3D cUS and fNIRS are promising bedside tools for monitoring the progression of GMH-IVH in preterm neonates.

Association between endotypes of prematurity and pharmacological closure of patent ductus arteriosus: A systematic review and meta-analysis

Introduction

Endotypes leading to very and extremely preterm birth are clustered into two groups: infection/inflammation and dysfunctional placentation. We conducted a systematic review of observational studies exploring the association between these two endotypes and the pharmacological closure of patent ductus arteriosus (PDA) induced by cyclooxygenase (COX) inhibitors. Chorioamnionitis represented the infectious-inflammatory endotype, while dysfunctional placentation proxies were hypertensive disorders of pregnancy (HDP) and small for gestational age (SGA) or intrauterine growth restriction.

Methods

PubMed/Medline and Embase databases were searched. The random-effects odds ratio (OR) and 95% confidence interval (CI) were calculated for each association. We included 30 studies (12,639 infants).

Results

Meta-analysis showed a significant association between exposure to HDP and increased rate of pharmacological closure of PDA (17 studies, OR 1.41, 95% CI 1.10-1.81, p = 0.006). In contrast, neither chorioamnionitis (13 studies, OR 0.75, 95% CI 0.47-1.18, p = 0.211) nor SGA (17 studies, OR 1.20, 95% CI 0.96-1.50, p = 0.115) were significantly associated with the response to therapy. Subgroup analyses showed that the higher response to COX inhibitors in the HDP group was significant for indomethacin (OR 1.568, 95% CI 1.147-2.141, p = 0.005) but not for ibuprofen (OR 1.107, 95% CI 0.248-4.392, p = 0.894) or for the studies using both drugs (OR 1.280, 95% CI 0.935-1.751, p = 0.124). However, meta-regression showed that this difference between the drugs was not statistically significant (p = 0.404).

Discussion/Conclusion

Our data suggest that the pathologic condition that triggers prematurity may alter the response to pharmacological treatment of PDA. The DA of infants exposed to HDP appears to be more responsive to COX inhibitors.

Association of patent ductus arteriosus with fetal factors and endotypes of prematurity

During fetal life, the ductus arteriosus (DA) acquires the mechanisms for its postnatal closure following a thorough developmental program. This program can be interrupted by preterm birth and is also susceptible to alteration during fetal life by numerous physiological and pathological stimuli. In this review, we aim to summarize the evidence on how physiological and pathological factors affect DA development, eventually leading to patent DA (PDA). Specifically, we reviewed the associations of sex, race, and pathophysiological pathways leading to very preterm birth (endotypes) with PDA incidence and pharmacological closure. Summary of evidence suggests that there are no male-female differences in the incidence of PDA among very preterm infants. In contrast, risk of developing PDA appears to be higher in infants exposed to chorioamnionitis or who are small for gestational age. Finally, hypertensive disorders of pregnancy may be associated with a better response to pharmacological treatment of PDA. All of this evidence comes from observational studies and therefore associations do not imply causation. The current trend for many neonatologists is to wait for the natural evolution of preterm PDA. Continued research is needed to identify which fetal and perinatal factors modulate the eventual late closure of PDA in very and extremely preterm infants.

Association of Funisitis with Short-Term Outcomes of Prematurity: A Frequentist and Bayesian Meta-Analysis

The fetal systemic inflammatory response associated with intra-amniotic inflammation may play a key role in the pathogenesis of complications of preterm birth. Funisitis is the histologic equivalent of the fetal inflammatory response, whereas chorioamnionitis represents a maternal inflammatory response. We conducted a frequentist and Bayesian model average (BMA) meta-analysis of studies investigating the effects of funisitis on short-term outcomes of prematurity. Thirty-three studies (12,237 infants with gestational age ≤ 34 weeks) were included. Frequentist meta-analysis showed that funisitis was associated with an increased risk of any bronchopulmonary dysplasia (BPD), moderate/severe BPD, retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), any sepsis, early-onset sepsis (EOS), and mortality. However, Bayesian meta-analysis showed that the evidence in favor of the alternative hypothesis (i.e., funisitis is associated with an increased risk of developing the outcome) was strong for any IVH, moderate for severe IVH and EOS, and weak for the other outcomes. When the control group was restricted to infants having chorioamnionitis without funisitis, the only outcome associated with funisitis was any IVH. In conclusion, our data suggest that the presence of funisitis does not add an additional risk to preterm birth when compared to chorioamnionitis in the absence of fetal inflammatory response.

Comparison of Neonatal Morbidity and Mortality Following Spontaneous and Medically Indicated Preterm Births: A Retrospective Population-Based Study Using Data from the Slovenian National Perinatal Information System 2013-2018

BACKGROUND This retrospective population-based study analyzed data from the Slovenian National Perinatal Information System (NPIS) between 2013 and 2018 to compare neonatal morbidity and mortality following spontaneous and medically indicated preterm births. MATERIAL AND METHODS Retrospective population-based cohort. Entries to the NPIS database were searched by gestational age (GA) <37 weeks in Slovenia between 2013 and 2018. Of 9200 (6252 following spontaneous birth, 2948 following medically indicated) neonates included, 1358 were born at extremely to very preterm GA (998 following spontaneous birth, 360 following medically indicated). Logistic regression analysis was used to examine the association between neonatal mortality and composite severe neonatal morbidity and preterm birth type (spontaneous vs medically indicated) controlling for potential confounding variables. Analysis was first performed for all preterm births (GA 22 0/7 to 36 6/7) and later only for extremely to very preterm births (GA 22 0/7 to 31 6/7). RESULTS Neonatal mortality was significantly lower following spontaneous preterm birth at extremely to very preterm GA (odds ratio [OR] 0.34; 95% confidence interval [CI] [0.14, 0.81]), while there was no association in all preterm births group (OR 0.56; 95% CI [0.26, 1.20]). No significant correlation between preterm birth type and neonatal morbidity was found (OR 0.76; 95% CI [0.54, 1.09] for all preterm births and OR 0.71; 95% CI [0.47, 1.07] for extremely to very preterm births). CONCLUSIONS In this population study from Slovenia between 2013 and 2018, medically indicated preterm births at <32 weeks of GA were associated with significantly increased neonatal mortality but not neonatal morbidity.

Olfactomedin-4-Positive Neutrophils in Neonates: Link to Systemic Inflammation and Bronchopulmonary Dysplasia

INTRODUCTION

Little is known about the interplay between neutrophil heterogeneity in neonates in health and disease states. Olfactomedin-4 (OLFM4) marks a subset of neutrophils that have been described in adults and pediatric patients but not neonates, and this subset is thought to play a role in modulating the host inflammatory response.

METHODS

This is a prospective cohort of neonates who were born between June 2020 and December 2021 at the University of Cincinnati Medical Center NICU. Olfactomedin-4-positive (OLFM4+) neutrophils were identified in the peripheral blood using flow cytometry.

RESULTS

OLFM4+ neutrophil percentage was not correlated with gestational age or developmental age. Neonates with sepsis had a higher percentage than those without the condition, 66.9% (IQR 24.3-76.9%) versus 21.5% (IQR 10.6-34.7%), respectively, p = 0.0003. At birth, a high percentage of OLFM4+ neutrophils was associated with severe chorioamnionitis at 49.1% (IQR 28.2-61.5%) compared to those without it at 13.7% (IQR 7.7-26.3%), p < 0.0001. Among neonates without sepsis, the percentages of OLFM4+ neutrophils were lower in the BPD/early death group compared to those without BPD, 11.8% (IQR 6.3-29.0%) versus 32.5% (IQR 18.5-46.1%), p = 0.003, and this retained significance in a multiple logistic regression model that included gestational age, birthweight, and race.

CONCLUSION

This is the first study describing OLFM4+ neutrophils in neonates and it shows that this neutrophil subpopulation is not influenced by gestational age but is elevated in inflammatory conditions such as sepsis and severe chorioamnionitis, and lower percentage at birth is associated with developing bronchopulmonary dysplasia.

Very Low Birth Weight Outcomes and Admission Temperature: Does Hyperthermia Matter?

National and international recommendations for thermal care at preterm birth include recommendations to avoid hypothermia and hyperthermia. There is limited evidence demonstrating harm resulting from admission hyperthermia. Our aim was to assess the relationships between admission temperature and outcomes in very low birth weight (VLBW) babies in a unit with low rates of hypothermia and a higher rate of hyperthermia. This was an observational study based on routinely collected data including demographics, admission temperature, survival and major morbidity outcomes. Subjects were 1104 consecutive inborn VLBW babies admitted to a Neonatal Intensive Care Unit in United Kingdom between 2010 and 2017. Results: 155 (14%) of babies were hypothermic (<36.5 °C) with only 21 (1.9%) < 36 °C, and 254 (23%) of babies were hyperthermic (>37.5 °C). The rate of major abnormality on cranial ultrasound scan was increased in the hyperthermic babies compared to the normothermic babies (37/239 (15.5%) vs. 54/601 (9%), relative risk (95% CI) 1.723 (1.166 to 2.546), p = 0.006). There was no difference in survival or other major morbidity in the hyperthermic babies compared to the normothermic babies. There was no association between hypothermia and survival or any major morbidity, although this probably reflects the low power of the study given the low rates of significant hypothermia. Higher admission temperature was associated with an increase in the risk of major cranial ultrasound abnormality using multiple logistic regression analysis (p = 0.007) with an increased odds ratio (95% CI) of 1.48 (1.11 to 1.97) for each degree of increase. We conclude that admission hyperthermia is independently associated with an increased risk of preterm brain injury. It is not possible to state whether this is a causative association, or whether the association is a consequence of a shared aetiology of perinatal infection.

Histological severity of maternal and fetal inflammation is correlated with the prevalence of maternal clinical signs

AIM

To evaluate whether there is a stepwise increase in the prevalence of maternal clinical signs according to the severity of histological inflammation in the chorioamniotic membranes, placenta, and umbilical cord in preterm deliveries.

METHODS

This retrospective study, conducted between January 2007 and May 2017, included patients with preterm delivery between 22 and 33 weeks. The histological findings of maternal/fetal inflammatory responses were staged and graded according to the Amsterdam Placental Workshop Group consensus statement. Correlations between the histological severity of maternal/fetal inflammatory responses and the prevalence of clinical chorioamnionitis and clinical signs were evaluated using the Cochran-Armitage trend test.

RESULTS

A total of 138 patients were included. The stage and grade of the maternal inflammatory response were correlated with earlier gestational weeks at delivery and lighter birth weight. The prevalence of clinical chorioamnionitis was significantly correlated with a higher stage and grade of the maternal inflammatory response (Gibbs/Lencki criteria: 15.8%/15.8% in Stage 3, 16.3%/14% in Grade 2). No significant correlations were observed between gestational weeks at delivery and birth weight and stage/grade of fetal inflammatory response. The prevalence of clinical chorioamnionitis was significantly correlated with higher stage and grade of fetal inflammatory response (Gibbs/Lencki criteria: 25%/25% in Stage 3 and 29.4%/29.4% in Grade 2).

CONCLUSION

Correlations exist between the severity of histological maternal/fetal inflammatory responses and the prevalence of clinical chorioamnionitis and positive maternal clinical signs in preterm deliveries. However, the prevalence of clinical chorioamnionitis was 20%-30% even in the most severe fetal inflammatory responses.

Maintaining Normothermia in Preterm Babies during Stabilisation with an Intact Umbilical Cord

Background: We had experienced an increase in admission hypothermia rates during implementation of deferred cord clamping (DCC) in our unit. Our objective was to reduce the number of babies with a gestation below 32 weeks who are hypothermic on admission, whilst practising DCC and providing delivery room cuddles (DRC). Method: A 12 month quality improvement project set, in a large Neonatal Intensive Care Unit, from January 2020 to December 2020. Monthly rates of admission hypothermia (<36.5 °C) for all eligible babies, were tracked prospectively. Each hypothermic baby was reviewed as part of a series of Plan, Do, Study Act (PDSA) cycles, to understand potential reasons and to develop solutions. Implementation of these solutions included the dissemination of the learning through a variety of methods. The main outcome measure was the proportion of babies who were hypothermic (<36.5 °C) on admission compared to the previous 12 months. Results: 130 babies with a gestation below 32 weeks were admitted during the study period. 90 babies (69.2%) had DCC and 79 babies (60%) received DRC. Compared to the preceding 12 months, the rate of hypothermia decreased from 25/109 (22.3%) to 13/130 (10%) (p = 0.017). Only 1 baby (0.8%) was admitted with a temperature below 36 °C and 12 babies (9.2%) were admitted with a temperature between 36 °C and 36.4 °C. Continued monitoring during the 3 months after the end of the project showed that the improvements were sustained with 0 cases of hypothermia in 33 consecutive admissions. Conclusions: It is possible to achieve low rates of admission hypothermia in preterm babies whilst providing DCC and DRC. Using a quality improvement approach with PDSA cycles is an effective method of changing clinical practice to improve outcomes.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

Severe intraventricular hemorrhage causes long-lasting structural damage in a preterm rabbit pup model

BACKGROUND

Intraventricular hemorrhage causes significant lifelong mortality and morbidity, especially in preterm born infants. Progress in finding an effective therapy is stymied by a lack of preterm animal models with long-term follow-up. This study addresses this unmet need, using an established model of preterm rabbit IVH and analyzing outcomes out to 1 month of age.

METHODS

Rabbit pups were delivered preterm and administered intraperitoneal injection of glycerol at 3 h of life and approximately 58% developed IVH. Neurobehavioral assessment was performed at 1 month of age followed by immunohistochemical labeling of epitopes for neurons, synapses, myelination, and interneurons, analyzed by means of digital quantitation and assessed via two-way ANOVA or Student's t test.

RESULTS

IVH pups had globally reduced myelin content, an aberrant cortical myelination microstructure, and thinner upper cortical layers (I-III). We also observed a lower number of parvalbumin (PV)-positive interneurons in deeper cortical layers (IV-VI) in IVH animals and reduced numbers of neurons, synapses, and microglia. However, there were no discernable changes in behaviors.

CONCLUSIONS

We have established in this preterm pup model that long-term changes after IVH include significant wide-ranging alterations to cortical organization and microstructure. Further work to improve the sensitivity of neurocognitive testing in this species at this age may be required.

IMPACT

This study uses an established animal model of preterm birth, in which the rabbit pups are truly born preterm, with reduced organ maturation and deprivation of maternally supplied trophic factors. This is the first study in preterm rabbits that explores the impacts of severe intraventricular hemorrhage beyond 14 days, out to 1 month of age. Our finding of persisting but subtle global changes including brain white and gray matter will have impact on our understanding of the best path for therapy design and interventions.

Endothelial dysfunction in preterm infants: The hidden legacy of uteroplacental pathologies

Millions of infants are born prematurely every year worldwide. Prematurity, particularly at lower gestational ages, is associated with high mortality and morbidity and is a significant global health burden. Pregnancy complications and preterm birth syndrome strongly impact neonatal clinical phenotypes and outcomes. The vascular endothelium is a pivotal regulator of fetal growth and development. In recent years, the key role of uteroplacental pathologies impairing endothelial homeostasis is emerging. Conditions leading to very and extremely preterm birth can be classified into two main pathophysiological patterns or endotypes: infection/inflammation and dysfunctional placentation. The first is frequently related to chorioamnionitis, whereas the second is commonly associated with hypertensive disorders of pregnancy and fetal growth restriction. The nature, timing, and extent of prenatal noxa may alter fetal and neonatal endothelial phenotype and functions. Changes in the luminal surface, oxidative stress, growth factors imbalance, and dysregulation of permeability and vascular tone are the leading causes of endothelial dysfunction in preterm infants. However, the available evidence regarding endothelial physiology and damage is limited in neonates compared to adults. Herein, we discuss the current knowledge on endothelial dysfunction in the infectious/inflammatory and dysfunctional placentation endotypes of prematurity, summarizing their molecular features, available biomarkers, and clinical impact. Furthermore, knowledge gaps, shadows, and future research perspectives are highlighted.

Intracranial Hemorrhage and 2-Year Neurodevelopmental Outcomes in Infants Born Extremely Preterm

OBJECTIVES

To determine the incidence, timing, progression, and risk factors for intracranial hemorrhage (ICH) in infants 24^0/7 to 27^6/7 weeks of gestational age and to characterize the association between ICH and death or neurodevelopmental impairment (NDI) at 2 years of corrected age.

STUDY DESIGN

Infants enrolled in the Preterm Erythropoietin Neuroprotection Trial had serial cranial ultrasound scans performed on day 1, day 7-9, and 36 weeks of postmenstrual age to evaluate ICH. Potential risk factors for development of ICH were examined. Outcomes included death or severe NDI as well as Bayley Scales of Infant and Toddler Development, 3rd Edition, at 2 years of corrected age.

RESULTS

ICH was identified in 38% (n = 339) of 883 enrolled infants. Multiple gestation and cesarean delivery reduced the risk of any ICH on day 1. Risk factors for development of bilateral Grade 2, Grade 3, or Grade 4 ICH at day 7-9 included any ICH at day 1; 2 or more doses of prenatal steroids decreased risk. Bilateral Grade 2, Grade 3, or Grade 4 ICH at 36 weeks were associated with previous ICH at day 7-9. Bilateral Grade 2, any Grade 3, and any Grade 4 ICH at 7-9 days or 36 weeks of postmenstrual age were associated with increased risk of death or severe NDI and lower Bayley Scales of Infant and Toddler Development, 3rd Edition, scores.

CONCLUSIONS

Risk factors for ICH varied by timing of bleed. Bilateral and increasing grade of ICH were associated with death or NDI in infants born extremely preterm.

Preterm Birth Is Associated With Immune Dysregulation Which Persists in Infants Exposed to Histologic Chorioamnionitis

Introduction

Preterm infants are at increased risk of exposure to histologic chorioamnionitis (HCA) when compared to term-born controls, and this is associated with several neonatal morbidities involving brain, lungs and gut. Preterm infants could benefit from immunomodulatory therapies in the perinatal period, but development of rational treatment strategies requires improved characterization of the perinatal response to HCA. We had two objectives: The first, to characterize the umbilical cord blood immune profile in preterm infants compared to term-born controls; the second, to investigate the postnatal immune response in preterm infants exposed to HCA versus those who were not.

Population

For objective one 59 term infants [mean gestational age (GA) 39⁺⁴ (37⁺³ to 42⁺⁰)] and 55 preterm infants [mean GA29⁺⁰(23⁺³ to 32⁺⁰)] with umbilical cord samples available were included; for objective two we studied 96 preterm infants [mean GA29⁺¹(23⁺² to 32⁺⁰)] for whom placental histology and postnatal blood samples were available.

Methods

Placental histopathology was used to identify reaction patterns indicative of HCA, and a customized immunoassay of 24 inflammatory markers and trophic proteins selected to reflect the perinatal immune response was performed on umbilical cord blood in term and preterm participants and postnatal day 5 blood in the preterm group.

Results

The umbilical cord blood immune profile classified gestational age category with 86% accuracy (95% CI 0.78-0.92), p-value=1.242x10^-14. Pro-inflammatory proteins IL-6, MCP-1 and CRP were elevated in the cord blood of preterm infants whilst BDNF, C3, C9, IL-18, MMP-9 and RANTES were decreased, compared to infants born at term. In preterm infants, exposure to HCA was associated with elevations in 8 immune proteins on postnatal day 5 (BDNF, C3, C5a, C9, IL-8, MCP-1, MIP-1β and MMP-9) when compared to preterm infants who were not exposed.

Conclusion

Preterm birth is associated with a distinct immune profile in umbilical cord blood and preterm infants exposed to HCA with evidence of a fetal inflammatory response have specific alterations in immune function that are apparent on day 5 of postnatal life.

Turkish Neonatal Society Guideline on the Diagnosis and Management of Germinal Matrix Hemorrhage-Intraventricular Hemorrhage and Related Complications

Germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) remains an important cause of brain injury in preterm infants, and is associated with high rates of mortality and adverse neurodevelopmental outcomes, despite the recent advances in perinatal care. Close neuroimaging is recommended for both the detection of GMH-IVH and for the follow-up of serious complications, such as post-hemorrhagic ventricular dilatation (PHVD). Although the question when best to treat PHVD remains a matter of debate, recent literature on this topic shows that later timing of interventions predicted higher rates of neurodevelopmental impairment, emphasizing the importance of a well-structured neuroimaging protocol and timely interventions. In this guideline, pathophysiologic mechanisms, preventive measures, and clinical presentations of GMH-IVH and PHVD will be presented, and a neuroimaging protocol as well as an optimal treatment approach will be proposed in light of the recent literature.

A multicenter retrospective study on survival rate and complications of very preterm infants

OBJECTIVES

To study the survival rate and the incidence of complications of very preterm infants and the factors influencing the survival rate and the incidence of complications.

METHODS

The medical data of the very preterm infants with a gestational age of <32 weeks and who were admitted to the Department of Neonatology in 11 hospitals of Jiangsu Province in China from January 2018 to December 2019 were retrospectively reviewed. Their survival rate and the incidence of serious complications were analyzed. A multivariate logistic regression analysis was used to evaluate the risk factors for death and serious complications in very preterm infants.

RESULTS

A total of 2 339 very preterm infants were enrolled, among whom 2 010 (85.93%) survived and 1 507 (64.43%) survived without serious complications. The groups with a gestational age of 22-25⁺⁶ weeks, 26-26⁺⁶ weeks, 27-27⁺⁶ weeks, 28-28⁺⁶ weeks, 29-29⁺⁶ weeks, 30-30⁺⁶ weeks, and 31-31⁺⁶ weeks had a survival rate of 32.5%, 60.6%, 68.0%, 82.9%, 90.1%, 92.3%, and 94.8% respectively. The survival rate tended to increase with the gestational age (P<0.05) and the survival rate without serious complications in each gestational age group was 7.5%, 18.1%, 34.5%, 52.2%, 66.7%, 75.7%, and 81.8% respectively, suggesting that the survival rate without serious complications increased with the gestational age (P<0.05). The multivariate logistic regression analysis showed that high gestational age, high birth weight, and prenatal use of glucocorticoids were protective factors against death in very preterm infants (P<0.05), and 1-minute Apgar score ≤3 was a risk factor for death in very preterm infants (P<0.05); high gestational age and high birth weight were protective factors against serious complications in very preterm infants who survived (P<0.05), while 5-minute Apgar score ≤3 and maternal chorioamnionitis were risk factors for serious complications in very preterm infants who survived (P<0.05).

CONCLUSIONS

The survival rate is closely associated with gestational age in very preterm infants. A low 1-minute Apgar score (≤3) may increase the risk of death in very preterm infants, while high gestational age, high birth weight, and prenatal use of glucocorticoids are associated with the reduced risk of death. A low 5-minute Apgar score (≤3) and maternal chorioamnionitis may increase the risk of serious complications in these infants, while high gestational age and high birth weight may reduce the risk of serious complications.

Chorioamnionitis and Risk for Maternal and Neonatal Sepsis: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the risk of maternal and neonatal sepsis associated with chorioamnionitis.

DATA SOURCES

PubMed, BIOSIS, and ClinicalTrials.gov databases were systematically searched for full-text articles in English from inception until May 11, 2020.

METHODS OF STUDY SELECTION

We screened 1,251 studies. Randomized controlled trials, case-control, or cohort studies quantifying a relationship between chorioamnionitis and sepsis in mothers (postpartum) or neonates born at greater than 22 weeks of gestation were eligible. Studies were grouped for meta-analyses according to exposures of histologic or clinical chorioamnionitis and outcomes of maternal or neonatal sepsis.

TABULATION, INTEGRATION, AND RESULTS

One hundred three studies were included, and 55 met criteria for meta-analysis (39 studies of preterm neonates, 10 studies of general populations of preterm and term neonates, and six studies of late preterm and term neonates). Study details and quantitative data were abstracted. Random-effects models were used to generate pooled odds ratios (ORs); most studies only reported unadjusted results. Histologic chorioamnionitis was associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 4.42 [95% CI 2.68-7.29] and 5.88 [95% CI 3.68-9.41], respectively). Clinical chorioamnionitis was also associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 6.82 [95% CI 4.93-9.45] and 3.90 [95% CI 2.74-5.55], respectively). Additionally, histologic and clinical chorioamnionitis were each associated with higher odds of late-onset sepsis in preterm neonates. Confirmed sepsis incidence was 7% (early-onset) and 22% (late-onset) for histologic and 6% (early-onset) and 26% (late-onset) for clinical chorioamnionitis-exposed neonates. Three studies evaluated chorioamnionitis and maternal sepsis and were inconclusive.

CONCLUSION

Both histologic and clinical chorioamnionitis were associated with early- and late-onset sepsis in neonates. Overall, our findings support current guidelines for preventative neonatal care. There was insufficient evidence to determine the association between chorioamnionitis and maternal sepsis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020156812.

Assessment of the fetal thymus gland: Comparing MRI-acquired thymus volumes with 2D ultrasound measurements

OBJECTIVES

The fetal thymus gland has been shown to involute in response to intrauterine infection, and therefore could be used as a non-invasive marker of fetal compartment infection. The objective of this study was to evaluate how accurately 2D ultrasound-derived measurements of the fetal thymus reflect the 3D volume of the gland derived from motion corrected MRI images.

STUDY DESIGN

A retrospective study was performed using paired ultrasound and MRI datasets from the iFIND project (http://www.ifindproject.com). To obtain 3D volumetry of the thymus gland, T2-weighted single shot turbo spin echo (ssTSE) sequences of the fetal thorax were acquired. Thymus volumes were manually segmented from deformable slice-to-volume reconstructed images. To obtain 2D ultrasound measurements, previously stored fetal cine loops were used and measurements obtained at the 3-vessel-view (3VV) and 3-vessel-trachea view (3VT): anterior-posterior diameter (APD), intrathoracic diameter (ITD), transverse diameter (TD), perimeter and 3-vessel-edge (3VE). Inter-observer and intra-observer reliability (ICC) was calculated for both MRI and ultrasound measurements. Pearson correlation coefficients (PCC) were used to compare 2D-parameters with acceptable ICC to TV.

RESULTS

38 participants were identified. Adequate visualisation was possible on 37 MRI scans and 31 ultrasound scans. Of the 30 datasets where both MRI and ultrasound data were available, MRI had good interobserver reliability (ICC 0.964) and all ultrasound 3VV 2D-parameters and 3VT 3VE had acceptable ICC (>0.75). Four 2D parameters were reflective of the 3D thymus volume: 3VV TD r = 0.540 (P = 0.002); 3VV perimeter r = 0.446 (P = 0.013); 3VV APD r = 0.435 (P = 0.110) and 3VT TD r = 0.544 (P = 0.002).

CONCLUSIONS

MRI appeared superior to ultrasound for visualization of the thymus gland and reproducibility of measurements. Three 2D US parameters, 3VV TD, perimeter and 3VT APD, correlated well with TV. Therefore, these represent a more accurate reflection of the true size of the gland than other 2D measurements, where MRI is not available.

Elevated neutrophil-lymphocyte ratios in extremely preterm neonates with histologic chorioamnionitis

OBJECTIVE

Histologic chorioamnionitis (HCA) is a placental inflammation linked to preterm birth and adverse neonatal outcome. The neutrophil-lymphocyte ratio (NLR) can identify various inflammatory disorders, however its utility in HCA is not clear. Our goal was to examine NLR values and HCA diagnoses in at-risk pregnancies and neonates.

STUDY DESIGN

We retrospectively analyzed the EHR of mothers and preterm (<33 wk GA) neonates with or without HCA (identified by placental histology). The NLR was calculated from complete blood counts in laboring women and in their neonates (0-24 h of life).

RESULT

In 712 consecutive gestations, 50.8% had HCA (26.5% fetal HCA). The neonatal NLR (0-12 h, 13-24 h) predicted fetal HCA better than chance alone (p = 0.01 and 0.002, respectively).

CONCLUSION

Early NLR elevation in preterm neonates is consistent with a diagnosis of fetal HCA. The NLR may identify preterm neonates at risk for HCA-related complications.

Neuroprotection of the Perinatal Brain by Early Information of Cerebral Oxygenation and Perfusion Patterns

Abnormal patterns of cerebral perfusion/oxygenation are associated with neuronal damage. In preterm neonates, hypoxemia, hypo-/hypercapnia and lack of cerebral autoregulation are related to peri-intraventricular hemorrhages and white matter injury. Reperfusion damage after perinatal hypoxic ischemia in term neonates seems related with cerebral hyperoxygenation. Since biological tissue is transparent for near infrared (NIR) light, NIR-spectroscopy (NIRS) is a noninvasive bedside tool to monitor brain oxygenation and perfusion. This review focuses on early assessment and guiding abnormal cerebral oxygenation/perfusion patterns to possibly reduce brain injury. In term infants, early patterns of brain oxygenation helps to decide whether or not therapy (hypothermia) and add-on therapies should be considered. Further NIRS-related technical advances such as the use of (functional) NIRS allowing simultaneous estimation and integrating of heart rate, respiration rate and monitoring cerebral autoregulation will be discussed.

Umbilical Cord Milking vs Delayed Cord Clamping and Associations with In-Hospital Outcomes among Extremely Premature Infants

OBJECTIVE

To compare in-hospital outcomes after umbilical cord milking vs delayed cord clamping among infants <29 weeks of gestation.

STUDY DESIGN

Multicenter retrospective study of infants born <29 weeks of gestation from 2016 to 2018 without congenital anomalies who received active treatment at delivery and were exposed to umbilical cord milking or delayed cord clamping. The primary outcome was mortality or severe (grade III or IV) intraventricular hemorrhage (IVH) by 36 weeks of postmenstrual age (PMA). Secondary outcomes assessed at 36 weeks of PMA were mortality, severe IVH, any IVH or mortality, and a composite of mortality or major morbidity. Outcomes were assessed using multivariable regression, incorporating mortality risk factors identified a priori, confounders, and center. A prespecified, exploratory analysis evaluated severe IVH in 2 gestational age strata, 22-24^6/7 and 25-28^6/7 weeks.

RESULTS

Among 1834 infants, 23.6% were exposed to umbilical cord milking and 76.4% to delayed cord clamping. The primary outcome, mortality or severe IVH, occurred in 21.1% of infants: 28.3% exposed to umbilical cord milking and 19.1% exposed to delayed cord clamping, with an aOR that was similar between groups (aOR 1.45, 95% CI 0.93, 2.26). Infants exposed to umbilical cord milking had higher odds of severe IVH (19.8% umbilical cord milking vs 11.8% delayed cord clamping, aOR 1.70 95% CI 1.20, 2.43), as did the 25-28^6/7 week stratum (14.8% umbilical cord milking vs 7.4% delayed cord clamping, aOR 1.89 95% CI 1.22, 2.95). Other secondary outcomes were similar between groups.

CONCLUSIONS

This analysis of extremely preterm infants suggests that delayed cord clamping is the preferred practice for placental transfusion, as umbilical cord milking exposure was associated with an increase in the adverse outcome of severe IVH.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00063063.

Placental pathology and intraventricular hemorrhage in preterm and small for gestational age infants

OBJECTIVE

The aim of this study was to examine the relationship between chorioamnionitis and vascular malperfusion on placental pathology and intraventricular hemorrhage (IVH) in premature and small for gestational age (SGA) infants.

STUDY DESIGN

A retrospective analysis of 263 infants ≤34 weeks gestation or ≤1800 g and their mothers was conducted by chart review for placental pathology and clinical data from 2014 to 2018. Unadjusted and adjusted odds ratios (OR) for the association of placental pathology with IVH were calculated.

RESULT

Unadjusted OR showed an association between acute chorioamnionitis and IVH, but logistic regression analysis showed a non-significant adjusted OR between acute or chronic chorioamnionitis with IVH. Maternal vascular malperfusion was significantly associated with increased IVH when controlling for confounders.

CONCLUSION

Placental maternal vascular malperfusion is associated with the development of IVH in premature and SGA infants when controlling for other confounders.

Evaluating the Effect of a Neonatal Care Bundle for the Prevention of Intraventricular Hemorrhage in Preterm Infants

Germinal matrix intraventricular hemorrhage (IVH) remains a severe and common complication in preterm infants. A neonatal care bundle (NCB) was implemented as an in-house guideline at a tertiary neonatal intensive care unit to reduce the incidence of IVH in preterm infants. The NCB was applied either to preterm infants <1250 g birth weight or <30 weeks gestational age or both, and standardized patient positioning, nursing care, and medical procedures within the first week of life. A retrospective cohort study was performed to investigate the effect of the NCB and other known risk factors on the occurrence and severity of IVH. Data from 229 preterm infants were analyzed. The rate of IVH was 26.2% before and 27.1% after implementing the NCB. The NCB was associated neither with reducing the overall rate of IVH (odds ratio (OR) 1.02; 95% confidence interval (CI) 0.57–1.84; p = 0.94) nor with severe IVH (OR 1.0; 95% CI 0.67–1.55; p = 0.92). After adjustment for group differences and other influencing factors, amnion infection syndrome and early intubation were associated with an increased risk for IVH. An NCB focusing on patient positioning, nursing care, and medical interventions had no impact on IVH in preterm infants. Known risk factors for IVH were confirmed.

Biomarkers for a histological chorioamnionitis diagnosis in pregnant women with or without group B streptococcus infection: a case-control study

Background

Chorioamnionitis may cause serious perinatal and neonatal adverse outcomes, and group B streptococcus (GBS) is one of the most common bacteria isolated from human chorioamnionitis. The present study analyzed the impact of GBS infection and histological chorioamnionitis (HCA) on pregnancy outcomes and the diagnostic value of various biomarkers.

Methods

Pregnant women were grouped according to GBS infection and HCA detection. Perinatal and neonatal adverse outcomes were recorded with a follow-up period of 6 weeks. The white blood cell count (WBC), neutrophil ratio, and C-reactive protein (CRP) level from peripheral blood and soluble intercellular adhesion molecule-1 (sICAM-1), interleukin 8 (IL-8), and tumor necrosis factor α (TNF-α) levels from cord blood were assessed.

Results

A total of 371 pregnant women were included. Pregnant women with GBS infection or HCA had a higher risk of pathological jaundice and premature rupture of membranes and higher levels of sICAM-1, IL-8, and TNF-α in umbilical cord blood. Univariate and multivariate regression analysis revealed that sICMA-1, IL-8, TNF-α, WBC, and CRP were significantly related to an increased HCA risk. For all included pregnant women, TNF-α had the largest receiver operating characteristic (ROC) area (area: 0.841; 95% CI: 0.778–0.904) of the biomarkers analyzed. TNF-α still had the largest area under the ROC curve (area: 0.898; 95% CI: 0.814–0.982) for non-GBS-infected pregnant women, who also exhibited a higher neutrophil ratio (area: 0.815; 95% CI: 0.645–0.985) and WBC (area: 0.849; 95% CI: 0.72–0.978), but all biomarkers had lower value in the diagnosis of HCA in GBS-infected pregnant women.

Conclusion

GBS infection and HCA correlated with several perinatal and neonatal adverse outcomes. TNF-α in cord blood and WBCs in peripheral blood had diagnostic value for HCA in non-GBS-infected pregnant women but not GBS-infected pregnant women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03731-7.

Germinal Matrix-Intraventricular Hemorrhage: A Tale of Preterm Infants

Germinal matrix-intraventricular hemorrhage (GM-IVH) is a common intracranial complication in preterm infants, especially those born before 32 weeks of gestation and very-low-birth-weight infants. Hemorrhage originates in the fragile capillary network of the subependymal germinal matrix of the developing brain and may disrupt the ependymal lining and progress into the lateral cerebral ventricle. GM-IVH is associated with increased mortality and abnormal neurodevelopmental outcomes such as posthemorrhagic hydrocephalus, cerebral palsy, epilepsy, severe cognitive impairment, and visual and hearing impairment. Most affected neonates are asymptomatic, and thus, diagnosis is usually made using real-time transfontanellar ultrasound. The present review provides a synopsis of the pathogenesis, grading, incidence, risk factors, and diagnosis of GM-IVH in preterm neonates. We explore brief literature related to outcomes, management interventions, and pharmacological and nonpharmacological prevention strategies for GM-IVH and posthemorrhagic hydrocephalus.

Risk factors and short-term complications of high-grade intraventricular hemorrhages in preterm neonates in training hospitals of Alborz

Objectives

The aim of this study is to determine risk factors and short-term complications of high-grade intraventricular hemorrhages (IVHs) in preterm neonates. Other topics of investigation include the increase in complications of IVH with its severity and the effect of IVH risk factors on the severity of IVH.

Materials & Methods

We conducted a retrospective case-control study of 436 consecutive preterm neonates with high-grade (3, 4) IVHs admitted in training hospitals of Alborz University in Karaj, Iran, from 2012 to 2017. The risk factors and short-term complications were assessed and analyzed in the subjects by SPSS 19.

Results

Out of 10 000 eligible neonates, we identified 1203 premature infants with IVH. A total of 436 infants with IVH grades 3 and 4 were allocated to the case group. The control group consisted of 767 infants with IVH grades 1 and 2. This study revealed that the most common risk factors of IVH include lack of corticosteroid use in 67.2%, low Apgar score in 10%, and surfactant use in 5.7% of the patients. Ten percent (31 cases) had short-term complications (18 hydrocephalus and 13 death cases). Male gender (P = .006) and lower gestational age (P = .0001) contributed to higher grades of IVH.

Conclusion

According to the results obtained in this study, it may be concluded that the lack of corticosteroid use is the most common risk factor for IVH, and short-term complications may be seen in one-tenth of the cases.

Genetic predictors of severe intraventricular hemorrhage in extremely low-birthweight infants

OBJECTIVE

To test associations between grades 3 or 4 (severe) intraventricular hemorrhage (IVH) and single nucleotide polymorphisms (SNPs) associated with coagulation, inflammation, angiogenesis, and organ development in an exploratory study.

STUDY DESIGN

Extremely low-birthweight (ELBW) infants enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's (NRN) Cytokines Study were included if they had cranial ultrasound (CUS) and genotyping data available in the NRN Anonymized DNA Repository and Database. Associations between SNPs and IVH severity were tested with multivariable logistic regression analysis.

RESULT

One hundred thirty-nine infants with severe IVH and 687 infants with grade 1 or 0 IVH were included. One thousand two hundred seventy-nine SNPs were genotyped. Thirteen were preliminarily associated with severe IVH including five related to central nervous system (CNS) neuronal and neurovascular development.

CONCLUSION

Genetic variants for CNS neuronal and neurovascular development may be associated with severe IVH in premature infants.

Mortality and neurological outcomes in extremely and very preterm infants born to mothers with hypertensive disorders of pregnancy

To evaluate the impact of maternal hypertensive disorders of pregnancy (HDP) on mortality and neurological outcomes in extremely and very preterm infants using a nationwide neonatal database in Japan. This population-based retrospective study was based on an analysis of data collected by the Neonatal Research Network of Japan from 2003 to 2015 of neonates weighing 1,500 g or less at birth, between 22 and 31 weeks’ gestation. A total of 21,659 infants were randomly divided into two groups, HDP (n = 4,584) and non-HDP (n = 4,584), at a ratio of 1:1 after stratification by four factors including maternal age, parity, weeks of gestation, and year of delivery. Short-term (neonatal period) and medium-term (3 years of age) mortality and neurological outcomes were compared between the two groups by logistic regression analyses. In univariate analysis, HDP was associated with an increased risk for in-hospital death (crude odds ratio [OR], 1.31; 95% confidence interval, 1.04–1.63) and a decreased risk for severe intraventricular haemorrhage (0.68; 0.53–0.87) and periventricular leukomalacia (0.60; 0.48–0.77). In multivariate analysis, HDP was significantly associated with a lower risk for in-hospital death (adjusted OR, 0.61; 0.47–0.80), severe intraventricular haemorrhage (0.47; 0.35–0.63), periventricular leukomalacia (0.59; 0.45–0.78), neonatal seizures (0.40; 0.28–0.57) and cerebral palsy (0.70; 0.52–0.95) at 3 years after adjustment for covariates including birth weight. These results were consistent with those of additional analyses, which excluded cases with histological chorioamnionitis and which divided the infants into two subgroups (22–27 gestational weeks and 28–31 gestational weeks). Maternal HDP was associated with an increased risk for in-hospital death without adjusting for covariates, but it was also associated with a lower risk for mortality and adverse neurological outcomes in extremely and very preterm infants if all covariates except HDP were identical.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

Elevated Pro-Inflammatory Cell-Free MicroRNA Levels in Cerebrospinal Fluid of Premature Infants after Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) represents a high risk of neonatal mortality and later neurodevelopmental impairment in prematurity. IVH is accompanied with inflammation, hemolysis, and extracellular hemoglobin (Hb) oxidation. However, microRNA (miRNA) expression in cerebrospinal fluid (CSF) of preterm infants with IVH has been unknown. Therefore, in the present study, candidate pro-inflammatory cell-free miRNAs were analyzed in CSF samples from 47 preterm infants with grade III or IV IVH vs. clinical controls (n = 14). miRNAs were quantified by RT-qPCR, normalized to “spike-in” cel-miR-39. Oxidized Hb and total heme levels were determined by spectrophotometry as well as IL-8, VCAM-1, ICAM-1, and E-selectin concentrations by ELISA. To reveal the origin of the investigated miRNAs, controlled hemolysis experiments were performed in vitro; in addition, human choroid plexus epithelial cell (HCPEpiC) cultures were treated with metHb, ferrylHb, heme, or TNF-α to replicate IVH-triggered cellular conditions. Levels of miR-223, miR-155, miR-181b, and miR-126 as well as Hb metabolites along with IL-8 were elevated in CSF after the onset of IVH vs. controls. Significant correlations were observed among the miRNAs, oxidized Hb forms, and the soluble adhesion molecules. During the post-IVH follow-up, attenuated expression of miRNAs and protein biomarkers in CSF was observed upon elimination of Hb metabolites. These miRNAs remained unaffected by a series of artificially induced hemolysis, which excluded red blood cells as their origin, while stimulation of HCPEpiCs with oxidized Hb fractions and heme resulted in increased extracellular miRNA levels in the cell culture supernatant. Overall, the hemorrhage-induced CSF miRNAs reflected inflammatory conditions as potential biomarkers in preterm IVH.

Placental Pathology Findings and the Risk of Intraventricular and Cerebellar Hemorrhage in Preterm Neonates

Placental pathology as a predisposing factor to intraventricular hemorrhage remains a matter of debate, and its contribution to cerebellar hemorrhage development is still largely unexplored. Our study aimed to assess placental and perinatal risk factors for intraventricular and cerebellar hemorrhages in preterm infants. This retrospective cohort study included very low-birth weight infants born at the Gaslini Children's Hospital between January 2012 and October 2016 who underwent brain magnetic resonance with susceptibility-weighted imaging at term-equivalent age and whose placenta was analyzed according to the Amsterdam Placental Workshop Group Consensus Statement. Of the 286 neonates included, 68 (23.8%) had intraventricular hemorrhage (all grades) and 48 (16.8%) had a cerebellar hemorrhage (all grades). After correction for gestational age, chorioamnionitis involving the maternal side of the placenta was found to be an independent risk factor for developing intraventricular hemorrhage, whereas there was no association between maternal and fetal inflammatory response and cerebellar hemorrhage. Among perinatal factors, we found that intraventricular hemorrhage was significantly associated with cerebellar hemorrhage (odds ratio [OR], 8.14), mechanical ventilation within the first 72 h (OR, 2.67), and patent ductus arteriosus requiring treatment (OR, 2.6), whereas cesarean section emerged as a protective factor (OR, 0.26). Inotropic support within 72 h after birth (OR, 5.24) and intraventricular hemorrhage (OR, 6.38) were independent risk factors for cerebellar hemorrhage, whereas higher gestational age was a protective factor (OR, 0.76). Assessing placental pathology may help in understanding mechanisms leading to intraventricular hemorrhage, although its possible role in predicting cerebellar bleeding needs further evaluation.

Evidence base multi-discipline critical strategies toward better tomorrow for very preterm infants

Despite advances in neonatal intensive care in the recent decade, a large number of very preterm infants (VPIs) remain at risk for significant neurodevelopmental impairment (NDI). Given that there are many interventions need to be implemented during the critical perinatal period so that complications of these vulnerable VPIs could be minimized, it is urgent to develop multi-discipline strategies based on evidence to be carried out. The objective of this new term evidence-based perinatal critical strategies (EBPCS), is to provide beneficial intervention towards better neurodevelopmental outcomes, specifically for preterm infants below 28 weeks gestational age. EBPCS is defined as the management of the VPIs during the perinatal period which would include antenatal counseling with team briefing and share decision making, treat the chorioamnionitis, antenatal MgS04, antenatal steroid, delayed cord clamping/milking, neonatal resuscitation team preparation, prevention of hypothermia, immediate respiratory support with continuous positive airway pressure at delivery room, less invasive surfactant administration, early surfactant with budesonide therapy, support of cardiovascular system, early initiate of probiotics administration, early caffeine, early parenteral and enteral nutrition, promptly initiating antibiotics. These critical strategies will be discussed detail in the text; nonetheless, standardized protocols, technical skills and repeated training are the cornerstones of successful of EBPCS. Further experience from different NICU is needed to prove whether these very complicate and comprehensive perinatal critical strategies could translate into daily practice to mitigate the incidence of NDI in high-risk VPIs.

Association of Histological and Clinical Chorioamnionitis With Neonatal Sepsis Among Preterm Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

Chorioamnionitis (CA) is considered a key risk factor for very preterm birth and for developing early onset sepsis (EOS) in preterm infants, but recent data suggest that CA might be protective against late onset sepsis (LOS). We performed a systematic review and meta-analysis of studies exploring the association between CA and sepsis. A comprehensive literature search was performed in PubMed/MEDLINE and EMBASE, from their inception to December 1, 2018. A random-effects model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Sources of heterogeneity were analyzed by subgroup and meta-regression analyses. The following categories of sepsis were analyzed: EOS, LOS, unspecified onset sepsis (UOS), culture-proven, and clinical sepsis. CA was subdivided into clinical and histological chorioamnionitis. Funisitis was also analyzed. We found 3,768 potentially relevant studies, of which 107 met the inclusion criteria (387,321 infants; 44,414 cases of CA). Meta-analysis showed an association between any CA and any EOS (OR 4.29, CI 3.63-5.06), any LOS (OR 1.29, CI 1.11-1.54), and any UOS (OR 1.59, CI 1.11-1.54). Subgroup analysis showed that CA was associated with culture-proven EOS (OR 4.69, CI 3.91-5.56), clinical EOS (OR 3.58, CI 1.90-6.76), and culture-proven LOS (OR 1.31, CI 1.12-1.53), but not with clinical LOS (OR 1.52, CI 0.78-2.96). The presence of funisitis did not increase the risk of either EOS or LOS when compared with CA without funisitis. CA-exposed infants had lower gestational age (-1.11 weeks, CI -1.37 to -0.84) than the infants not exposed to CA. Meta-regression analysis showed that the lower gestational age of the CA group correlated with the association between CA and LOS but not with the association between CA and EOS. In conclusion, our data suggest that the positive association between chorioamnionitis and LOS may be modulated by the effect of chorioamnionitis on gestational age.

Machine learning models for identifying preterm infants at risk of cerebral hemorrhage

Intracerebral hemorrhage in preterm infants is a major cause of brain damage and cerebral palsy. The pathogenesis of cerebral hemorrhage is multifactorial. Among the risk factors are impaired cerebral autoregulation, infections, and coagulation disorders. Machine learning methods allow the identification of combinations of clinical factors to best differentiate preterm infants with intra-cerebral bleeding and the development of models for patients at risk of cerebral hemorrhage. In the current study, a Random Forest approach is applied to develop such models for extremely and very preterm infants (23-30 weeks gestation) based on data collected from a cohort of 229 individuals. The constructed models exhibit good prediction accuracy and might be used in clinical practice to reduce the risk of cerebral bleeding in prematurity.

Association of Chorioamnionitis With Bronchopulmonary Dysplasia Among Preterm Infants: A Systematic Review, Meta-analysis, and Metaregression

IMPORTANCE

Bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, remains one of the major and most common complications of very preterm birth. Insight into factors associated with the pathogenesis of BPD is key to improving its prevention and treatment.

OBJECTIVE

To perform a systematic review, meta-analysis, and metaregression of clinical studies exploring the association between chorioamnionitis (CA) and BPD in preterm infants.

DATA SOURCES

PubMed and Embase were searched without language restriction (last search, October 1, 2018). Key search terms included bronchopulmonary dysplasia, chorioamnionitis, and risk factors.

STUDY SELECTION

Included studies were peer-reviewed studies examining preterm (<37 weeks' gestation) or very low-birth-weight (<1500 g) infants and reporting primary data that could be used to measure the association between exposure to CA and the development of BPD.

DATA EXTRACTION AND SYNTHESIS

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline was followed. Data were independently extracted by 2 researchers. A random-effects model was used to calculate odds ratios (ORs) and 95% CIs. Heterogeneity in effect size across studies was studied using multivariate, random-effects metaregression analysis.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD, defined as supplemental oxygen requirement on postnatal day 28 (BPD28) or at the postmenstrual age of 36 weeks (BPD36). Covariates considered as potential confounders included differences between CA-exposed and CA-unexposed infants in gestational age, rates of respiratory distress syndrome (RDS), exposure to antenatal corticosteroids, and rates of early- and late-onset sepsis.

RESULTS

A total of 3170 potentially relevant studies were found, of which 158 met the inclusion criteria (244 096 preterm infants, 20 971 CA cases, and 24 335 BPD cases). Meta-analysis showed that CA exposure was significantly associated with BPD28 (65 studies; OR, 2.32; 95% CI, 1.88-2.86; P < .001; heterogeneity: I2 = 84%; P < .001) and BPD36 (108 studies; OR, 1.29; 95% CI, 1.17-1.42; P < .001; heterogeneity: I2 = 63%; P < .001). The association between CA and BPD remained significant for both clinical and histologic CA. In addition, significant differences were found between CA-exposed and CA-unexposed infants in gestational age, birth weight, odds of being small for gestational age, exposure to antenatal corticosteroids, and early- and late-onset sepsis. Chorioamnionitis was not significantly associated with RDS (48 studies; OR, 1.10; 95% CI, 0.92-1.34; P = .24; heterogeneity: I2 = 90%; P < .001), but multivariate metaregression analysis with backward elimination revealed that a model combining the difference in gestational age and the odds of RDS was associated with 64% of the variance in the association between CA and BPD36 across studies.

CONCLUSIONS AND RELEVANCE

The results of this study confirm that among preterm infants, exposure to CA is associated with a higher risk of developing BPD, but this association may be modulated by gestational age and risk of RDS.

Reducing Germinal Matrix-Intraventricular Hemorrhage: Perinatal and Delivery Room Factors

Germinal matrix hemorrhage-intraventricular hemorrhage (IVH) is the most common form of brain injury in preterm infants. Although severe IVH has declined over the years, it still affects approximately 6% of infants born before 32 weeks of gestation. Most IVH cases are detectable by the first 24 hours after birth; therefore interventions to prevent IVH should focus on antenatal management for pregnant women and delivery room management. Obstetrical interventions, including antenatal corticosteroids, maternal rather than infant transport, and possibly elective cesarean delivery have been associated with a decreased risk of IVH. Neonatal interventions in the delivery room, including delayed cord clamping or umbilical cord milking, maintaining normothermia, avoiding fluctuations in cerebral blood flow, and optimal ventilation management are associated with a decreased risk of IVH. Multiple clinical trials are under way to further identify IVH risk factors, ability to monitor or predict IVH, and ideally prevent IVH altogether. This discussion will focus on reviewing current obstetric and neonatal management practices and their associations with germinal matrix hemorrhage-IVH.

Cerebellar Hemorrhage in Preterm Infants: A Meta-Analysis on Risk Factors and Neurodevelopmental Outcome

Cerebellar hemorrhage (CBH) represents the most commonly acquired lesion of the posterior fossa in the neonatal period. We aimed to perform a systematic review and meta-analysis of studies exploring the perinatal risk factors and neurological outcome of CBH in preterm infants. A comprehensive literature search was conducted using PubMed/MEDLINE and EMBASE. Studies were included if they examined preterm infants and reported primary data on maternal, obstetric, or perinatal characteristics, and/or outcomes of infants with and without CBH. A random-effects model was used to calculate mean differences (MD), odds ratios (OR), and 95% confidence intervals (CI). We found 231 potentially relevant studies, of which 15 met the inclusion criteria (4,236 infants, 347 CBH cases). Meta-analysis could not demonstrate a significant association between CBH and multiple gestation, chorioamnionitis, pre-eclampsia, placental abruption, use of antenatal corticosteroids, mode of delivery, or infant sex. Infants with CBH had a significantly lower gestational age (6 studies, MD −1.55 weeks, 95% CI −1.93 to −1.16) and birth weight (6 studies, MD −173 g, 95% CI −225 to −120), and significantly higher rates of intubation at birth, hypotension, patent ductus arteriosus, intraventricular hemorrhage, sepsis, necrotizing enterocolitis, and bronchopulmonary dysplasia. CBH was significantly associated with delayed mental (6 studies, OR 2.95, 95% CI 1.21 to 7.20) and psychomotor (6 studies, OR 3.62, 95% CI 1.34 to 9.76) development, and higher rates of cerebral palsy (4 studies, OR 3.09, 95% CI 1.55 to 6.19). In conclusion, the present meta-analysis shows that the youngest and sickest preterm infants are at higher risk of developing CBH. Our results highlight the multifactorial nature of CBH and reinforce the idea that cerebellar injury in very preterm newborns has important neurodevelopmental consequences among survivors.