Association of Intraventricular Hemorrhage and Death With Tocolytic Exposure in Preterm Infants

Tocolysis after preterm prelabor rupture of membranes and 5-year outcomes: a population-based cohort study

BACKGROUND

The administration of tocolytics after preterm prelabor rupture of membranes remains a controversial practice. In theory, reducing uterine contractility should delay delivery and allow for optimal antenatal management, thereby reducing the risks for prematurity and adverse consequences over the life course. However, tocolysis may be associated with neonatal death or long-term adverse neurodevelopmental outcomes, mainly related to prolonged fetal exposure to intrauterine infection or inflammation. In a previous study, we showed that tocolysis administration was not associated with short-term benefits. There are currently no data available to evaluate the impact of tocolysis on neurodevelopmental outcomes in school-aged children born prematurely in this clinical setting.

OBJECTIVE

This study aimed to investigate whether tocolysis administered after preterm prelabor rupture of membranes is associated with neurodevelopmental outcomes at 5.5 years of age.

STUDY DESIGN

We used data from a prospective, population-based cohort study of preterm births recruited in 2011 (referred to as the EPIPAGE-2 study) and for whom the results of a comprehensive medical and neurodevelopmental assessment of the infant at age 5.5 years were available. We included pregnant individuals with preterm prelabor rupture of membranes at 24 to 32 weeks' gestation in singleton pregnancies with a live fetus at the time of rupture, birth at 24 to 34 weeks' gestation, and participation of the infant in an assessment at 5.5 years of age. Exposure was the administration of any tocolytic treatment after preterm prelabor rupture of membranes. The main outcome was survival without moderate to severe neurodevelopmental disabilities at 5.5 years of age. Secondary outcomes included survival without any neurodevelopmental disabilities, cerebral palsy, full-scale intelligence quotient, developmental coordination disorders, and behavioral difficulties. A propensity-score analysis was used to minimize the indication bias in the estimation of the treatment effect on outcomes.

RESULTS

Overall, 596 of 803 pregnant individuals (73.4%) received tocolytics after preterm prelabor rupture of membranes. At the 5.5-year follow-up, 82.7% and 82.5% of the children in the tocolysis and no tocolysis groups, respectively, were alive without moderate to severe neurodevelopmental disabilities; 52.7% and 51.1%, respectively, were alive without any neurodevelopmental disabilities. After applying multiple imputations and inverse probability of treatment weighting, we found no association between the exposure to tocolytics and survival without moderate to severe neurodevelopmental disabilities (odds ratio, 0.93; 95% confidence interval, 0.55-1.60), survival without any neurodevelopmental disabilities (odds ratio, 1.02; 95% confidence interval, 0.65-1.61), or any of the other outcomes.

CONCLUSION

There was no difference in the neurodevelopmental outcomes at age 5.5 years among children with and without antenatal exposure to tocolysis after preterm prelabor rupture of membranes. To date, the health benefits of tocolytics remain unproven, both in the short- and long-term.

[Neurodevelopment and neuroprotection in young children]

In France, the most pessimistic estimates put the prevalence of neurodevelopmental disorders (NDD) at 15 % of births. The two largest populations of newborns at highest risk of NDD are premature babies and babies born into siblings with one or more infants who already have an autism spectrum disorder or another NDD. The high prevalence of these disorders justifies a health promotion policy, centred on the child and his or her family. Prevention is based on the early identification of high-risk factors, by informing families and training pregnancy and early childhood professionals, and implementing perinatal prevention protocols for high-risk newborns (antenatal corticosteroid therapy and magnesium sulfate for women at risk of preterm delivery before 32 weeks, developmental care, therapeutic hypothermia for full-term infants with early neonatal encephalopathy presumed to be anoxic). Preventing the severity of NDD depends on their early identification, as early as possible in the highest plastic "1000 days" developmental window, a smooth flow of diagnosis and care for mothers and children, and the establishment of an ecosystem that includes multi-modal early intervention, at the best in multi-disciplinary teams such as the early medical and social action centres, support for families through guidance programs and inclusion in the community, first in day-care centers and then in nursery schools.

Acquired Brain Injuries Across the Perinatal Spectrum: Pathophysiology and Emerging Therapies

The development of the central nervous system can be directly disrupted by a variety of acquired factors, including infectious, inflammatory, hypoxic-ischemic, and toxic insults. Influences external to the fetus also impact neurodevelopment, including placental health, maternal comorbidities, adverse experiences, environmental exposures, and social determinants of health. Acquired perinatal brain insults tend to affect the developing brain in a stage-specific manner that reflects the susceptible cell types, developmental processes, and risk factors present at the time of the insult. In this review, we discuss the pathophysiology, neurodevelopmental outcomes, and management of common acquired perinatal brain conditions. In the fetal brain, we divide insults based on trimester, and in the postnatal brain, we focus on common pathologies that have a presentation dependent on gestational age at birth: white matter injury and germinal matrix hemorrhage/intraventricular hemorrhage in preterm infants and hypoxic-ischemic encephalopathy in term infants. Although specific treatments for fetal and newborn brain disorders are currently limited, we emphasize therapies in preclinical or early clinical phases of the development pipeline. The growing number of novel cell type- and stage-specific emerging therapies suggests that in the near future we may have a dramatically improved ability to treat acquired perinatal brain disorders and to mitigate the associated neurodevelopmental consequences.

Hexoprenaline Compared with Atosiban as Tocolytic Treatment for Preterm Labor

Introduction Preterm birth is defined as a live birth before 37 weeks of gestation and is associated with increased neonatal morbidity and mortality. The aim of this study is to compare the efficacy of hexoprenaline and atosiban for short- and long-term tocolysis and their effects on neonatal and maternal outcomes.

Methods This retrospective cohort study included women with threatened preterm labor between 24 + 0 and 34 + 0 weeks of gestation without premature rupture of membranes. The tocolytic efficacy of hexoprenaline and atosiban was compared in women receiving one of the two medications for short- and long-term tocolysis. Continuous variables were compared using t-test or Mann–Whitney U test, as appropriate. Comparison of categorical variables between the two groups was done with χ ² test after Pearsonʼs and Fisherʼs exact test.

Results 761 women were enrolled in this study; 387 women received atosiban and 374 women received hexoprenaline as their primary tocolytic agent. Atosiban showed a higher efficacy as a primary tocolytic agent (p = 0.000) within 48 hours. As regards long-term tocolysis, there were no differences between the treatment groups (p = 0.466). Maternal side effects such as tachycardia (p = 0.018) or palpitations (p = 0.000) occurred more frequently after the administration of hexoprenaline, while there were no differences between the two drugs administered with regard to any other maternal or neonatal outcome parameter.

Conclusion Our retrospective study shows a significantly higher efficacy of atosiban in the first 48 hours, especially when administered at an early gestational age. There were no significant differences in terms of neonatal outcome but significantly more maternal adverse effects during the administration of hexoprenaline.

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.

Cohort protocol: Guangzhou High-Risk Infant Cohort study

INTRODUCTION

Despite the increase in the survival rate of high-risk infants (HRIs) worldwide, the prevalence of motor and neurodevelopmental sequelae in such newborns has not shown concomitant improvement. Meanwhile, there are few cohorts that explore factors related to the development of HRIs in China. Therefore, the Guangzhou High-Risk Infant Cohort (GHRIC) has been designed to examine the complex relationships among a myriad of factors influencing growth and development in such children.

METHODS AND ANALYSIS

The GHRIC study is a prospective cohort study that by the year 2023 will enrol an estimated total of 3000 HRIs from Guangzhou Women and Children's Medical Center (GWCMC) in Guangzhou, China. This study is designed to assess the growth and cognitive characteristics of HRIs and the risk factors affecting their development and prognoses. Data on risk factors, neurodevelopmental and cognitive-function evaluations, laboratory results, and specimens will be collected and analysed. Information on perinatal and clinical interventions for these infants will also be recorded during regular follow-up visits until age 6.

ETHICS AND DISSEMINATION

The protocol for this study has been approved by the Research Ethics Committee of GWCMC, which accepted responsibility for supervising all of the aspects of the study (No. 2017102712). Study outcomes will be disseminated through conference presentations, peer-reviewed publications, the Internet and social media.

TRIAL REGISTRATION NUMBER

ChiCTR-EOC-17013236.

Intraventricular Hemorrhage in Very Preterm Infants: A Comprehensive Review

Germinal matrix-intraventricular-intraparenchymal hemorrhage (GMH-IVH-IPH) is a major complication of very preterm births before 32 weeks of gestation (WG). Despite progress in clinical management, its incidence remains high before 27 WG. In addition, severe complications may occur such as post-hemorrhagic hydrocephalus and/or periventricular intraparenchymal hemorrhage. IVH is strongly associated with subsequent neurodevelopmental disabilities. For this review, an automated literature search and a clustering approach were applied to allow efficient filtering as well as topic clusters identification. We used a programmatic literature search for research articles related to intraventricular hemorrhage in preterms that were published between January 1990 and February 2020. Two queries ((Intraventricular hemorrhage) AND (preterm)) were used in PubMed. This search resulted in 1093 articles. The data manual curation left 368 documents that formed 12 clusters. The presentation and discussion of the clusters provide a comprehensive overview of existing data on the pathogenesis, complications, neuroprotection and biomarkers of GMH-IVH-IPH in very preterm infants. Clinicians should consider that the GMH-IVH-IPH pathogenesis is mainly due to developmental immaturity of the germinal matrix and cerebral autoregulation impairment. New multiomics investigations of intraventricular hemorrhage could foster the development of predictive biomarkers for the benefit of very preterm newborns.

The effect of antenatal magnesium sulfate on intraventricular hemorrhage in premature infants: a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis study was to determine the pooled estimate of the effect of antenatal magnesium sulfate (MgSO4) on intraventricular hemorrhage (IVH) in premature infants.

METHODS

Two review authors independently searched all randomized clinical trials from international databases, including Medline (PubMed), Web of Sciences, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Research Registers of ongoing trials (ClinicalTrials.gov), from January 1989 to August 2017. Two independent review authors were responsible for data collection. After extracting the necessary information from the evaluated articles, metaanalysis of the data was performed using Stata version 14. Also, sources of heterogeneity among studies were determined by Meta regression.

RESULTS

In this study, among 126 articles that were extracted from primary studies, 7 papers that evaluated the effect of MgSO4 on IVH were eligible for inclusion in the meta-analysis. The results of the meta-analysis showed that pooled relative risk (95% confidence interval [CI]) was 0.80 (95% CI, 0.63 to 1.03) for the effect of MgSO4 on IVH.

CONCLUSION

RESULTS

of this study showed that although MgSO4 had a protective effect on IVH in premature infants, this effect was not statistically significant. Further studies are needed to determine the best dosage, timing, and gestational age to achieve the optimum effect of MgSO4 on IVH.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) Identifier: CRD42019119610.

The orphan nuclear receptor Nr4a1 mediates perinatal neuroinflammation in a murine model of preterm labor

Prematurity is associated with perinatal neuroinflammation and injury. Screening for genetic modulators in an LPS murine model of preterm birth revealed the upregulation of Nr4a1, an orphan nuclear transcription factor that is normally absent or limited in embryonic brains. Concurrently, Nr4a1 was downregulated with magnesium sulfate (MgSO₄) and betamethasone (BMTZ) treatments administered to LPS exposed dams. To understand the role of Nr4a1 in perinatal brain injury, we compared the preterm neuroinflammatory response in Nr4a1 knockout (KO) versus wild type (wt) mice. Key inflammatory factors Il1b, Il6 and Tnf, and Iba1+ microglia were significantly lower in Nr4a1 KO versus wt brains exposed to LPS in utero. Treatment with MgSO₄/BMTZ mitigated the neuroinflammatory process in wt but not Nr4a1 KO brains. These results correspond with a reduction in cerebral hemorrhage in wt but not mutant embryos from dams given MgSO₄/BMTZ. Further analysis with Nr4a1-GFP-Cre × tdTomato loxP reporter mice revealed that the upregulation of Nr4a1 with perinatal neuroinflammation occurs in the cerebral vasculature. Altogether, this study implicates Nr4a1 in the developing vasculature as a potent mediator of neuroinflammatory brain injury that occurs with preterm birth. It is also possible that MgSO₄/BMTZ mitigates this process by direct or indirect inhibition of Nr4a1.

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.