Maternal antenatal complications and the risk of neonatal cerebral white matter damage and later cerebral palsy in children born at an extremely low gestational age

Two risk assessment models for predicting white matter injury in extremely preterm infants

BACKGROUND

Extremely preterm infants (EPIs) are at high-risk of white matter injury (WMI), leading to long-term neurodevelopmental impairments. We aimed to develop nomograms for WMI.

METHODS

The study included patients from 31 provinces, spanning ten years. 6074 patients before 2018 were randomly divided into a training and internal validation group (7:3). The external validation group comprised 1492 patients from 2019. Predictors were identified using the least absolute shrinkage and selection operator (LASSO) and multivariable logistic regression and nomograms were constructed. Models' performance was evaluated using receiver operating characteristic (ROC), decision curve analysis (DCA) and calibration curves.

RESULTS

The prenatal nomogram included multiple gestation, premature rupture of membranes (PROM), chorioamnionitis, prenatal glucocorticoids, hypertensive disorder complicating pregnancy (HDCP) and Apgar 1 min, with area under the curve (AUC) of 0.805, 0.816 and 0.799 in the training, internal validation and external validation group, respectively. Days of mechanical ventilation (MV), shock, patent ductus arteriosus (PDA) ligation, intraventricular hemorrhage (IVH) grade III-IV, septicemia, hypothermia and necrotizing enterocolitis (NEC) stage II-III were identified as postpartum predictors. The AUCs were 0.791, 0.813 and 0.823 in the three groups, respectively. DCA and calibration curves showed good clinical utility and consistency.

CONCLUSION

The two nomograms provide clinicians with precise and efficient tools for prediction of WMI.

IMPACT

This study is a large-sample multicenter study, spanning 10 years. The two nomograms are convenient for identifying high-risk infants early, allowing for reducing poor prognosis.

The aetiology of preterm birth and risks of cerebral palsy and cognitive impairment: A systematic review and meta-analysis

AIM

The associations between the aetiology of preterm birth and later neurodevelopmental outcomes are unclear. A systematic review and meta-analysis examined the existing evidence.

METHODS

The PubMed and Embase databases were searched for papers published in English from inception to 16 December 2020. We included original papers on the causes of preterm birth and the risks of cerebral palsy (CP) and suboptimal cognitive development. Two reviewers independently evaluated the studies and extracted the data.

RESULTS

The literature search yielded 5472 papers and 13 were selected. The aetiology of preterm birth was classified under spontaneous or medically indicated delivery. A meta-analysis was performed, comprising 104 902 preterm infants from 11 papers on CP. Preterm infants born after a medically indicated delivery had a lower CP risk than infants born after spontaneous delivery, with a pooled odds ratio of 0.59 (95% confidence interval 0.40-0.86). This result was robust in the subgroup and sensitivity analyses. Cognitive development was reported in three papers, which suggested that worse outcomes were associated with medically indicated deliveries.

CONCLUSION

The aetiology of preterm delivery may contribute to the risk of CP and cognitive delay. Further research is needed, using individual-level meta-analyses to adjust for possible confounders, notably gestational age.

Small for gestational age at preterm birth identifies adverse neonatal outcomes more reliably than antenatal suspicion of fetal growth restriction

BACKGROUND

Fetal growth restriction (FGR) is an important reason for premature delivery and a leading cause of perinatal morbidity and mortality. We aimed to evaluate whether classification as small for gestational age (SGA; <10th centile) at birth or antenatal suspicion of FGR was more strongly associated with neonatal morbidity and mortality in preterm infants.

METHODS

A retrospective audit of infants born between 24 + 0 and 32 + 6 weeks of gestation from 2012-2019 and admitted to the Neonatal Unit at Mercy Hospital for Women (MHW). Infants were categorized according to whether FGR was listed as an antenatal complication in the medical records and whether they were SGA (<10th centile on Fenton chart) or appropriate for gestational age (AGA) at birth, and comparisons for neonatal outcomes were made.

RESULTS

371/2126 preterm infants (17.5%) had antenatal suspicion of FGR, and 166 (7.8%) were SGA at birth. No differences in any neonatal outcomes were found between infants with or without suspected FGR, except decreased intraventricular hemorrhage (IVH) in the FGR group. SGA classification was associated with increased rates of all morbidities other than IVH, including bronchopulmonary dysplasia, retinopathy of prematurity, and necrotizing enterocolitis, compared with the AGA group. Death was significantly higher in the SGA group (7.2%) compared with the AGA group (3.5%).

CONCLUSION

SGA by Fenton chart more reliably identified neonates at risk of adverse neonatal outcomes than antenatal suspicion of FGR, suggesting it is a reasonable clinical proxy. This most likely reflects the much lower tenth centile weight cutoffs on the Fenton charts compared to in-utero charts used antenatally to diagnose FGR based on ultrasound estimated fetal weight. SGA classification by Fenton approximately equates to <3rd centile on in-utero charts at our institution, therefore identifying the most severe FGR cases.

The Global Pregnancy Collaboration (CoLab) symposium on short- and long-term outcomes in offspring whose mothers had preeclampsia: A scoping review of clinical evidence

Preeclampsia is a maternal syndrome characterized by the new onset of hypertension after 20 weeks of gestation associated with multisystemic complications leading to high maternal and fetal/neonatal morbidity and mortality. However, sequelae of preeclampsia may extend years after pregnancy in both mothers and their children. In addition to the long-term adverse cardiovascular effects of preeclampsia in the mother, observational studies have reported elevated risk of cardiovascular, metabolic, cerebral and cognitive complications in children born from women with preeclampsia. Less clear is whether the association between maternal preeclampsia and offspring sequelae are causal, or to what degree the associations might be driven by fetal factors including impaired growth and the health of its placenta. Our discussion of these complexities in the 2018 Global Pregnancy Collaboration annual meeting prompted us to write this review. We aimed to summarize the evidence of an association between maternal preeclampsia and neurobehavioral developmental disorders in offspring in hopes of generating greater research interest in this important topic.

Evaluation of Long-term Outcomes Associated With Preterm Exposure to Antenatal Corticosteroids: A Systematic Review and Meta-analysis

IMPORTANCE

Animal studies have found that antenatal corticosteroids affect many organs across multiple stages of life. However, the long-term outcomes in human children are not well understood.

OBJECTIVE

To conduct a systematic review and meta-analysis of long-term outcomes associated with preterm exposure to antenatal corticosteroids compared with no exposure in all children as well as children with preterm and full-term birth.

DATA SOURCES

Academic databases were searched for articles published from January 1, 2000, to October 29, 2021, including Ovid MEDLINE, Ovid Embase, PsycInfo, CINAHL (Cumulative Index of Nursing and Allied Health Literature), Web of Science, ClinicalTrials.gov, and Google Scholar. References of articles were also searched for relevant studies.

STUDY SELECTION

Randomized clinical trials (RCTs), quasi-RCTs, and cohort studies that assessed long-term neurodevelopmental, psychological, or other outcomes at 1 year or older in those who had preterm exposure to antenatal corticosteroids were included. No language restrictions were set.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data using a piloted data extraction form. Data on study population, pregnancy characteristics, exposure to antenatal corticosteroids, and outcomes were collected. Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines were followed, and random-effects models were used for the meta-analysis.

MAIN OUTCOMES AND MEASURES

The primary outcome was an author-defined composite of any adverse neurodevelopmental and/or psychological disorder. The secondary outcomes included specific measures of psychological disorders; neurodevelopmental delay; and anthropometric, metabolic, and cardiorespiratory outcomes.

RESULTS

A total of 30 studies met the inclusion criteria, and involved more than 1.25 million children who were at least 1 year of age when the outcomes were assessed. Exposure to a single course of antenatal corticosteroids for children with extremely preterm birth was associated with a significant reduction in risk of neurodevelopmental impairment (adjusted odds ratio, 0.69 [95% CI, 0.57-0.84]; I2 = 0%; low certainty). For children with late-preterm birth, exposure to antenatal corticosteroids was associated with a higher risk of investigation for neurocognitive disorders (n = 25 668 children; adjusted hazard ratio [aHR], 1.12 [95% CI, 1.05-1.20]; low certainty). For children with full-term birth, exposure to antenatal corticosteroids was associated with a higher risk of mental or behavioral disorders (n = 641 487 children; aHR, 1.47 [95% CI, 1.36-1.60]; low certainty) as well as proven or suspected neurocognitive disorders (n = 529 205 children; aHR, 1.16 [95% CI, 1.10-1.21]; low certainty).

CONCLUSIONS AND RELEVANCE

Results of this study showed that exposure to a single course of antenatal corticosteroids was associated with a significantly lower risk of neurodevelopmental impairment in children with extremely preterm birth but a significantly higher risk of adverse neurocognitive and/or psychological outcomes in children with late-preterm and full-term birth, who made up approximately half of those with exposure to antenatal corticosteroids. The findings suggest a need for caution in administering antenatal corticosteroids.

Preeclampsia and Cerebral Palsy in Offspring

The aim of this systematic review and meta-analysis is to examine the association between exposure to preeclampsia during pregnancy and the occurrence of cerebral palsy in offspring. For this reason, the authors searched PubMed/Medline, EMBASE, and Google Scholar databases (end-of-search: 22 November 2021) and identified the most relevant studies. Then, a meta-analysis of all the eligible studies was performed. Subgroup and meta-regression analyses by study design, degree of adjustment, and geographical region were also conducted. A total of 10 studies were finally included, and no statistical significance was noted in the association between preeclampsia and cerebral palsy (pooled OR = 1.16, 95% CI: 0.77–1.74). The subgroup of studies that provided adjusted odds ratios for any variable except for gestational age showed a statistically significant association (pooled OR = 1.62, 95% CI: 1.36–1.93), whereas the association dissipated in studies also adjusting for gestational age (pooled OR = 1.63, 95% CI: 0.48–5.50). In conclusion, it seems that preeclampsia is not associated with cerebral palsy independently of gestational age; however, further research is needed to shed light on this topic.

Placental programming, perinatal inflammation, and neurodevelopment impairment among those born extremely preterm

Individuals born extremely preterm are at significant risk for impaired neurodevelopment. After discharge from the neonatal intensive care, associations between the child's well-being and factors in the home and social environment become increasingly apparent. Mothers' prenatal health and socioeconomic status are associated with neurodevelopmental outcomes, and emotional and behavioral problems. Research on early life risk factors and on mechanisms underlying inter-individual differences in neurodevelopment later in life can inform the design of personalized approaches to prevention. Here, we review early life predictors of inter-individual differences in later life neurodevelopment among those born extremely preterm. Among biological mechanisms that mediate relationships between early life predictors and later neurodevelopmental outcomes, we highlight evidence for disrupted placental processes and regulated at least in part via epigenetic mechanisms, as well as perinatal inflammation. In relation to these mechanisms, we focus on four prenatal antecedents of impaired neurodevelopment, namely, (1) fetal growth restriction, (2) maternal obesity, (3) placental microorganisms, and (4) socioeconomic adversity. In the future, this knowledge may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm. IMPACT: This review highlights early life risk factors and mechanisms underlying inter-individual differences in neurodevelopment later in life. The review emphasizes research on early life risk factors (fetal growth restriction, maternal obesity, placental microorganisms, and socioeconomic adversity) and on mechanisms (disrupted placental processes and perinatal inflammation) underlying inter-individual differences in neurodevelopment later in life. The findings highlighted here may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm.

Maternal Overweight, Inflammation and Neurological Consequences for the Preterm Child: Results of the ELGAN Study

Maternal overweight and obesity are prenatal risk factors for obstetrical complications, preterm birth, neonatal morbidity as well as cognitive and behavioural developmental disorders in children. Paediatric morbidity and mortality as well as child development disorders are significantly associated with maternal obesity. Particularly in the neurodevelopmental and psychiatric area, it is becoming increasingly clear that, in children of mothers with an increased body mass index (BMI), there is a high correlation with childhood cognitive disabilities, attention disorders, and diseases on the autistic spectrum. The ELGAN (Extremely Low Gestational Age Newborn) study is a multicentre study which has been supported since 2000 by the National Institutes of Health (NIH) and whose objective is to research predictors for neonatal brain damage and neurological-cognitive sequelae in premature infants. The areas of focus are the connection between maternal overweight and obesity and pregnancy complications, APGAR scores and systemic inflammatory markers. In this overview, our aim is to summarise the work in this area and discuss it critically on the basis of current literature. We will examine the hypothesis whether maternal overweight and obesity in terms of a chronic inflammatory state is associated with neonatal inflammation which in turn is associated with an unfavourable development prognosis.

Association Between Funisitis and Childhood Intellectual Development: A Prospective Cohort Study

Background: Previous studies have suggested that prenatal inflammation could damage the immature brain of preterm infants. In this study, we aimed to investigate whether funisitis could affect childhood neurodevelopment. We hypothesized that childhood neurodevelopment would vary across groups with or without funisitis.

Material sand Methods: Using data from the U.S. Collaborative Perinatal Project (1959–1976), 29,725 subjects with available intelligence quotient (IQ) were studied. Detailed placental examinations were conducted according to a standard protocol with quality control procedures. Multivariate logistic regression models were applied to evaluate the relationship between funisitis and IQ at age 4 or 7 years after adjusting for confounders.

Results: Early preterm birth children with funisitis had a 3.0-fold (95% confidence interval 1.2, 7.3) risk of low full-scale IQ (<70) at age 4 years, which disappeared until age 7 years. Term birth children with funisitis had 1.9-fold (95% confidence interval 1.2, 3.0) risk of low performance IQ at age 7 years, but they did not have increased risk of low full-scale IQ. No difference in IQ score was found in late preterm birth children.

Conclusion: Funisitis may injure the developmental brain of infants, leading to the relative low IQ in childhood at age 4, but the negative effect is only existed in performance IQ at age of 7.

Both antenatal and postnatal inflammation contribute information about the risk of brain damage in extremely preterm newborns

BackgroundPreterm newborns exposed to intrauterine inflammation are at an increased risk of neurodevelopmental disorders. We hypothesized that adverse outcomes are more strongly associated with a combination of antenatal and postnatal inflammation than with either of them alone.MethodsWe defined antenatal inflammation as histologic inflammation in the placenta. We measured the concentrations of seven inflammation-related proteins in blood obtained on postnatal days 1, 7, and 14 from 763 infants born before 28 weeks of gestation. We defined postnatal inflammation as a protein concentration in the highest quartile on at least 2 days. We used logistic regression models to evaluate the contribution of antenatal and postnatal inflammation to the risk of neurodevelopmental disorders.ResultsThe risk of white matter damage was increased when placental inflammation was followed by sustained elevation of C-reactive protein or ICAM-1. We found the same for spastic cerebral palsy when placental inflammation was followed by elevation of TNF-α or IL-8. The presence of both placental inflammation and elevated levels of IL-6, TNF-α, or ICAM-1 was associated with an increased risk for microcephaly.ConclusionCompared with a single hit, two inflammatory hits are associated with stronger risk for abnormal cranial ultrasound, spastic cerebral palsy, and microcephaly at 2 years.

Detection and assessment of brain injury in the growth-restricted fetus and neonate

Fetal growth restriction (FGR) is a common complication of pregnancy and, in severe cases, is associated with elevated rates of perinatal mortality, neonatal morbidity, and poor neurodevelopmental outcomes. The leading cause of FGR is placental insufficiency, with the placenta failing to adequately meet the increasing oxygen and nutritional needs of the growing fetus with advancing gestation. The resultant chronic fetal hypoxia induces a decrease in fetal growth, and a redistribution of blood flow preferentially to the brain. However, this adaptation does not ensure normal brain development. Early detection of brain injury in FGR, allowing for the prediction of short- and long-term neurodevelopmental consequences, remains a significant challenge. Furthermore, in FGR infants the detection and diagnosis of neuropathology is complicated by preterm birth, the etiological heterogeneity of FGR, timing of onset of growth restriction, its severity, and coexisting complications. In this review, we examine existing and emerging diagnostic tools from human and preclinical studies for the detection and assessment of brain injury in FGR fetuses and neonates. Increased detection rates, and early detection of brain injury associated with FGR, will offer opportunities for developing and assessing interventions to improve long-term outcomes.

SGA as a Risk Factor for Cerebral Palsy in Moderate to Late Preterm Infants: a System Review and Meta-analysis

Small for gestational age (SGA) is an established risk factor for cerebral palsy (CP) in term infants. However, there is conflicting data on the association between SGA and CP in moderate to late preterm infants. The aim of the article was to explore the relationship between SGA and CP in the moderate to late preterm infants and its strength by meta-analysis. We performed a system search in OVID (EMBASE and MEDLINE) and WANFANG from inception to May 2016. The study-specific risk estimates were pooled using the random-effect model. A total of seven studies were included in the meta-analysis, consisting of three cohort and four case-control studies. A statistically significant association was found between SGA and CP in moderate to late premature infants (OR: 2.34; 95% CI: 1.43-3.82). The association were higher in the several subgroups: 34-36 week gestational age (OR: 3.47; 95% CI: 1.29-9.31), SGA < 2SDs (OR: 3.48; 95% CI: 1.86-6.49), and malformation included in CP (OR: 3.00; 95% CI: 1.71-5.26). In moderate to late premature infants, SGA is a convenient and reliable predictor for CP. More studies are needed to explore the underlying mechanisms between SGA and CP association.

Antenatal glucocorticoids and neonatal inflammation-associated proteins

BACKGROUND

To date, studies of the relationship between antenatal glucocorticoids (AGC) and neonatal inflammation in preterm newborns have been largely limited to umbilical cord blood specimens.

AIM

To explore the association between exposure to antenatal glucocorticoids and concentrations of inflammation-related proteins in whole blood collected from very preterm newborns at multiple times during the first postnatal month.

METHODS

We measured the protein concentrations on postnatal day 1 (N=1118), day 7 (N=1138), day 14 (N=1030), day 21 (N=936) and day 28 (N=877) from infants born before the 28th week of gestation and explored the relationship between antenatal steroid receipt and protein concentrations in the highest and lowest quartiles. The creation of multinomial logistic regression models (adjusted for potential confounders) allowed us calculate odds ratios and 95% confidence intervals.

RESULTS

Twenty of 420 assessments [21 (proteins)×2 (exposure levels: partial and full)×2 (quartile levels: top and bottom)×5 (days)] were statistically significant without any cohesive pattern.

CONCLUSION

Among infants born before 28 weeks of gestational age, neither full, nor partial courses of antenatal glucocorticoids have a sustained anti-inflammatory effect.

Controlled direct effects of preeclampsia on neonatal health after accounting for mediation by preterm birth

BACKGROUND

Preeclampsia is characterized by alterations in angiogenic factors that may increase neonatal morbidity independent of preterm birth.

METHODS

We estimated the controlled direct effect of preeclampsia on neonatal outcomes independent of preterm birth among 200,103 normotensive and 10,507 preeclamptic singleton pregnancies in the Consortium on Safe Labor (2002-2008). Marginal structural models with stabilized inverse probability weights accounted for potential confounders in the pathway from preeclampsia to preterm birth to neonatal outcomes, including mediator-outcome confounders related to preeclampsia status, such as cesarean delivery. Controlled direct effects of preeclampsia on perinatal mortality, small for gestational age (SGA), neonatal intensive care unit (NICU) admission, respiratory distress syndrome, transient tachypnea of the newborn, anemia, apnea, asphyxia, peri- or intraventricular hemorrhage, and cardiomyopathy were estimated for the hypothesized intervention of term delivery for all infants.

RESULTS

When delivery was set at ≥37 weeks, preeclampsia increased the odds of perinatal mortality (odds ratio = 2.2 [95% confidence interval = 1.1-4.5], SGA = (1.9 [1.8-2.1]), NICU admission (1.9 [1.7-2.1]), respiratory distress syndrome (2.8 [2.0-3.7], transient tachypnea of the newborn (1.6 [1.3-1.9]), apnea (2.2 [1.6-3.1]), asphyxia (2.7 [1.5-4.9]), and peri- or intraventricular hemorrhage (3.2 [1.4-7.7]). No direct effect of preeclampsia at term was observed for anemia or cardiomyopathy. Our results appear robust in the presence of moderate confounding, and restriction to severe preeclampsia yielded similar findings.

CONCLUSION

Preeclampsia was directly associated with adverse neonatal outcomes beyond morbidity mediated by preterm birth. Although severe neonatal outcomes were less common at later gestational ages, marginal structural models suggested elevated neonatal risk due to preeclampsia even if it was possible to deliver all infants at term.

Systemic inflammation and cerebral palsy risk in extremely preterm infants

The authors hypothesized that among extremely preterm infants, elevated concentrations of inflammation-related proteins in neonatal blood are associated with cerebral palsy at 24 months. In 939 infants born before 28 weeks gestation, the authors measured blood concentrations of 25 proteins on postnatal days 1, 7, and 14 and evaluated associations between elevated protein concentrations and cerebral palsy diagnosis. Protein elevations within 3 days of birth were not associated with cerebral palsy. Elevations of tumor necrosis factor-α, tumor necrosis factor-α-receptor-1, interleukin-8, and intercellular adhesion molecule-1 on at least 2 days were associated with diparesis. Recurrent-persistent elevations of interleukin-6, E-selectin, or insulin-like growth factor binding protein-1 were associated with hemiparesis. Diparesis and hemiparesis were more likely among infants who had at least 4 of 9 protein elevations that previously have been associated with cognitive impairment and microcephaly. Repeated elevations of inflammation-related proteins during the first 2 postnatal weeks are associated with increased risk of cerebral palsy.

Correlation of quantitative texture analysis of cranial ultrasound with later neurobehavior in preterm infants

The purpose of the study was to evaluate the association between a quantitative texture analysis of early neonatal brain ultrasound images and later neurobehavior in preterm infants. A prospective cohort study including 120 preterm (<33 wk of gestational age) infants was performed. Cranial ultrasound images taken early after birth were analyzed in six regions of interest using software based on texture analysis. The resulting texture scores were correlated with the Neonatal Behavioural Assessment Scale (NBAS) at term-equivalent age. The ability of texture scores, in combination with clinical data and standard ultrasound findings, to predict the NBAS results was evaluated. Texture scores were significantly associated with all but one NBAS domain and better predicted NBAS results than clinical data and standard ultrasound findings. The best predictive value was obtained by combining texture scores with clinical information and ultrasound standard findings (area under the curve = 0.94). We conclude that texture analysis of neonatal cranial ultrasound-extracted quantitative features that correlate with later neurobehavior has a higher predictive value than the combination of clinical data with abnormalities in conventional cranial ultrasound.

The association between sex-related interleukin-6 gene polymorphisms and the risk for cerebral palsy

BACKGROUND

The relationship between genetic factors and the development of cerebral palsy (CP) has recently attracted much attention. Polymorphisms in the genes encoding proinflammatory cytokines have been shown to be associated with susceptibility to perinatal brain injury and development of CP. Interleukin-6 (IL-6) is a proinflammatory cytokine that plays a pivotal role in neonatal brain injury, but conflicting results have been reported regarding the association between IL-6 single nucleotide polymorphisms (SNPs) and CP. The purpose of this study was to analyze IL-6 gene polymorphisms and protein expression and to explore the role of IL-6 in the Chinese CP population.

METHODS

A total of 753 healthy controls and 713 CP patients were studied to detect the presence of five SNPs (rs1800796, rs2069837, rs2066992, rs2069840, and rs10242595) in the IL-6 locus. Of these, 77 healthy controls and 87 CP patients were selected for measurement of plasma IL-6 by Luminex assay. The SHEsis program was used to analyze the genotyping data. For all comparisons; multiple testing on each individual SNP was corrected by the SNPSpD program.

RESULTS

There were no differences in allele or genotype frequencies between the overall CP patients and controls among the five genetic polymorphisms. However, subgroup analysis found significant sex-related differences in allele and genotype frequencies. Differences were found between spastic CP and controls in males for rs2069837; between CP with periventricular leukomalacia and controls in males for rs1800796 and rs2066992; and between term CP and controls in males for rs2069837. Plasma IL-6 levels were higher in CP patients than in the controls, and this difference was more robust in full-term male spastic CP patients. Furthermore, the genotype has an effect on IL-6 synthesis.

CONCLUSIONS

The influence of IL-6 gene polymorphisms on IL-6 synthesis and the susceptibility to CP is related to sex and gestational age.

A novel molecular microbiologic technique for the rapid diagnosis of microbial invasion of the amniotic cavity and intra-amniotic infection in preterm labor with intact membranes

PROBLEM

The diagnosis of microbial invasion of the amniotic cavity (MIAC) has been traditionally performed using traditional cultivation techniques, which require growth of microorganisms in the laboratory. Shortcomings of culture methods include the time required (days) for identification of microorganisms, and that many microbes involved in the genesis of human diseases are difficult to culture. A novel technique combines broad-range real-time polymerase chain reaction with electrospray ionization time-of-flight mass spectrometry (PCR/ESI-MS) to identify and quantify genomic material from bacteria and viruses.

METHOD OF STUDY

AF samples obtained by transabdominal amniocentesis from 142 women with preterm labor and intact membranes (PTL) were analyzed using cultivation techniques (aerobic, anaerobic, and genital mycoplasmas) as well as PCR/ESI-MS. The prevalence and relative magnitude of intra-amniotic inflammation [AF interleukin 6 (IL-6) concentration ≥ 2.6 ng/mL], acute histologic chorioamnionitis, spontaneous preterm delivery, and perinatal mortality were examined.

RESULTS

(i) The prevalence of MIAC in patients with PTL was 7% using standard cultivation techniques and 12% using PCR/ESI-MS; (ii) seven of ten patients with positive AF culture also had positive PCR/ESI-MS [≥17 genome equivalents per PCR reaction well (GE/well)]; (iii) patients with positive PCR/ESI-MS (≥17 GE/well) and negative AF cultures had significantly higher rates of intra-amniotic inflammation and acute histologic chorioamnionitis, a shorter interval to delivery [median (interquartile range-IQR)], and offspring at higher risk of perinatal mortality, than women with both tests negative [90% (9/10) versus 32% (39/122) OR: 5.6; 95% CI: 1.4-22; (P < 0.001); 70% (7/10) versus 35% (39/112); (P = 0.04); 1 (IQR: <1-2) days versus 25 (IQR: 5-51) days; (P = 0.002), respectively]; (iv) there were no significant differences in these outcomes between patients with positive PCR/ESI-MS (≥17 GE/well) who had negative AF cultures and those with positive AF cultures; and (v) PCR/ESI-MS detected genomic material from viruses in two patients (1.4%).

CONCLUSION

(i) Rapid diagnosis of intra-amniotic infection is possible using PCR/ESI-MS; (ii) the combined use of biomarkers of inflammation and PCR/ESI-MS allows for the identification of specific bacteria and viruses in women with preterm labor and intra-amniotic infection; and (iii) this approach may allow for administration of timely and specific interventions to reduce morbidity attributed to infection-induced preterm birth.

Hypoxic/ischemic and infectious events have cumulative effects on the risk of cerebral palsy in very-low-birth-weight preterm infants

BACKGROUND

Hypoxia/ischemia and inflammation are two major mechanisms for cerebral palsy (CP) in preterm infants.

OBJECTIVE

To investigate whether hypoxia/ischemia- and infection-related events in the perinatal and neonatal periods had cumulative effects on CP risk in very-low-birth-weight (VLBW) premature infants.

METHODS

From 1995 to 2005, 5,807 VLBW preterm infants admitted to Taiwan hospitals were enrolled. The cumulative effects of hypoxic/ischemic and infectious events during the perinatal and neonatal periods on CP risk at corrected age 24 months were analyzed.

RESULTS

Of the 4,355 infants with 24-month follow-up, 457 (10.5%) had CP. The CP group had significantly higher incidences of hypoxia/ischemia-related events in the perinatal and neonatal periods, and sepsis in the neonatal period than the normal group. Three hypoxic/ischemic events, including birth cardiopulmonary resuscitation (OR 2.25; 95% CI 1.81-2.82), patent ductus arteriosus (PDA) ligation (2.94; 1.35-5.75) and chronic lung disease (3.14; 2.61-3.85) had the most significant contribution to CP. Relative to CP risk for infants with neither the three hypoxic/ischemic events nor sepsis, the CP odds increased 1.98-, 2.26- and 2.15-fold for infants with birth cardiopulmonary resuscitation, PDA ligation and chronic lung disease, respectively; while the combination with sepsis further increased the odds to 3.18-, 3.83- and 3.25-fold, respectively. Using the three hypoxic/ischemic events plus sepsis, CP rates were 10.0, 16.7, 26.7, 40.0 and 54.7% for infants with none, one, two, three and four events, respectively.

CONCLUSIONS

Hypoxic/ischemic and infectious events across the perinatal and neonatal periods exerted cumulative effects on CP risk in VLBW premature infants.

Incidence of preeclampsia: risk factors and outcomes associated with early- versus late-onset disease

OBJECTIVE

The population-based incidence of early-onset (<34 weeks) and late-onset preeclampsia (≥34 weeks) has not been adequately studied. We examined the gestational age-specific incidence of preeclampsia onset and identified the associated risk factors and birth outcomes.

STUDY DESIGN

All singleton deliveries in Washington State, 2003-2008 (n = 456,668), were included, and preeclampsia onset was determined from hospital records linked to birth certificates. Cox and logistic regression models were used to obtain adjusted hazard ratios and odds ratios (AORs) for risk factors and birth outcomes, respectively.

RESULTS

The overall preeclampsia rate was 3.1% and the incidence increased sharply with gestation; early- and late-onset preeclampsia rates were 0.38% and 2.72%, respectively. Among women with early-onset preeclampsia, 12% delivered at a gestation of 34 weeks or longer. Risk/protective factors common to both diseases included older maternal age, Hispanic and Native-American race, smoking, unmarried status, and male fetus. African-American race, chronic hypertension, and congenital anomalies were more strongly associated with early-onset preeclampsia, whereas younger maternal age, nulliparity, and diabetes mellitus were more strongly associated with late-onset disease. Early- but not late-onset preeclampsia conferred a high risk of fetal death (AOR, 5.8; 95% confidence interval [CI], 4.0-8.3 vs AOR, 1.3; 95% CI, 0.8-2.0, respectively). The AOR for perinatal death/severe neonatal morbidity was 16.4 (95% CI, 14.5-18.6) in early-onset and 2.0 (95% CI, 1.8-2.3) in late-onset preeclampsia.

CONCLUSION

Early- and late-onset preeclampsia shares some etiological features, differ with regard to several risk factors, and lead to different outcomes. The 2 preeclampsia types should be treated as distinct entities from an etiological and prognostic standpoint.

Assessment of interleukin-6, interleukin-8 and interleukin-18 count in the serum of IUGR newborns

AIM

Aim of this study was to assess concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-18 (IL-18) in the serum of newborns with diagnosed intrauterine growth restriction (IUGR) in comparison to concentrations in serum of newborns with weight appropriate for gestational age (AGA).

MATERIALS

Research was conducted at the Lodz Medical University Clinic of Neonatology during 2010-2011. Surveyed group consisted of 50 hypotrophic full-term infants of single pregnancies (average weight: 2329 ± 287 g); control group, enclosing 50 infants AGA (average weight: 3544 ± 2161 g). Both groups received average Apgar score of 9 points. Concentrations of analysed cytokines were marked between 4-6 hours after birth. The enzyme-linked immunosorbent assay (ELISA) test was used to determine interleukins concentrations. Study was prospective. Statistics on the data were conducted with the Kolmogorov-Smirnov test. Significance level: p < 0.05.

RESULTS

Concentrations of IL-6 and IL-18 were elevated in the IUGR group in a statistically significant manner in comparison to the control group.

CONCLUSIONS

An elevated level of IL-6 and IL-18 in the IUGR group, comparing to control group, signifies the existence of inflammation in the process of developing IUGR, therefore, screening tests estimating levels of interleukins as IL-6 and IL-18 might be clinically useful in predicting the occurrence of IUGR and help preventing it.

Mediators of the association between pre-eclampsia and cerebral palsy: population based cohort study

OBJECTIVE

To test the hypothesis that pre-eclampsia is a risk factor for cerebral palsy mediated through preterm birth and being born small for gestational age.

DESIGN

Population based cohort study.

SETTING

Clinical data from the Norwegian Cerebral Palsy Registry were linked with perinatal data prospectively recorded by the Medical Birth Registry of Norway.

PARTICIPANTS

All singleton babies who survived the neonatal period during 1996-2006 (849 children with cerebral palsy and 616,658 control children).

MAIN OUTCOME MEASURES

Cerebral palsy and cerebral palsy subtypes.

RESULTS

Children exposed to pre-eclampsia had an excess risk of cerebral palsy (unadjusted odds ratio 2.5, 95% confidence interval 2.0 to 3.2) compared with unexposed children. Among children born at term (≥ 37 weeks), exposure to pre-eclampsia was not associated with an excess risk of cerebral palsy in babies not born small for gestational age (1.2, 0.7 to 2.0), whereas children exposed to pre-eclampsia and born small for gestational age had a significantly increased risk of cerebral palsy (3.2, 1.5 to 6.7). Non-small for gestational age babies born very preterm (<32 weeks) and exposed to pre-eclampsia had a reduced risk of cerebral palsy compared with unexposed children born at the same gestational age (0.5, 0.3 to 0.8), although the risk was not statistically significantly reduced among children exposed to pre-eclampsia and born small for gestational age (0.7, 0.4 to 1.3). Exposure to pre-eclampsia was not associated with a specific cerebral palsy subtype.

CONCLUSIONS

Exposure to pre-eclampsia was associated with an increased risk of cerebral palsy, and this association was mediated through the children being born preterm or small for gestational age, or both. Among children born at term, pre-eclampsia was a risk factor for cerebral palsy only when the children were small for gestational age.

Fetal placental inflammation is associated with poor neonatal growth of preterm infants: a case-control study

OBJECTIVE

To determine whether there is an association between histological chorioamnionitis (HCA) and postnatal growth of preterm infants in the neonatal period.

METHOD

This case-control study is part of a larger prospective histological study on placentas performed in all deliveries prior to 32 weeks of gestation. Eligible cases involved all placentas with a diagnosis of HCA. Control subjects were those without HCA, matched 1:1 with case subjects according to gestational age (±1 week). Placental inflammatory status and serial weight gain were analyzed for all infants during the first four postnatal weeks. Based on placental inflammation extension, HCA was defined as maternal HCA (MHCA) or fetal HCA (FHCA).

RESULTS

Of the 320 mother-infant pairs, 71 (22.1%) presented with HCA (27 MHCA and 44 FHCA). Decreases in weight gain at 21 and 28 days were associated with the presence of FHCA (β coefficient ± SE = -4.40 ± 2.21, p = 0.05 and -6.92 ± 2.96, p = 0.02, respectively), whereas no significant differences were found between MHCA and no-HCA groups. FHCA and MHCA were not identified as risk factors of weekly weight gain, after adjusting for possible confounders (maternal ethnicity, parity, smoking during pregnancy, infant gender, IUGR status, SGA status, antenatal steroids, total fluid intake, late-onset sepsis, BPD).

CONCLUSIONS

We found an association between fetal placental inflammation and poor neonatal growth but we were not able to identify a specific week wherein weight gain could be mostly affected. Placental findings may be used to identify preterm infants at risk of postnatal growth failure.

Brain damage in preterm newborns and maternal medication: the ELGAN Study

OBJECTIVE

We sought to evaluate the association between maternal medication use during pregnancy and cerebral white matter damage and cerebral palsy (CP) among very preterm infants.

STUDY DESIGN

This analysis of data from the Extremely Low Gestational Age Newborns (ELGAN) Study included 877 infants born <28 weeks' gestation. Mothers were interviewed, charts were reviewed, placentas were cultured and assessed histologically, and children were evaluated at 24 months corrected age. A diagnostic algorithm classified neurologic findings as quadriparetic CP, diparetic CP, hemiparetic CP, or no CP.

RESULTS

After adjustment for the potential confounding of disorders for which medications might have been indicated, the risk of quadriparetic CP remained elevated among the infants of mothers who consumed aspirin (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.3-6.9) and nonsteroidal antiinflammatory drugs (NSAIDs) (OR, 2.4; 95% CI, 1.04-5.8). The risk of diparetic CP was also associated with maternal consumption of an NSAID, but only if the consumption was not approved by a physician (OR, 3.5; 95% CI 1.1-11.0).

CONCLUSION

The possibility that aspirin and NSAID use in pregnancy could lead to perinatal brain damage cannot be excluded.

JNK signaling is the shared pathway linking neuroinflammation, blood-brain barrier disruption, and oligodendroglial apoptosis in the white matter injury of the immature brain

BACKGROUND

White matter injury is the major form of brain damage in very preterm infants. Selective white matter injury in the immature brain can be induced by lipopolysaccharide (LPS)-sensitized hypoxic-ischemia (HI) in the postpartum (P) day 2 rat pups whose brain maturation status is equivalent to that in preterm infants less than 30 weeks of gestation. Neuroinflammation, blood-brain barrier (BBB) damage and oligodendrocyte progenitor apoptosis may affect the susceptibility of LPS-sensitized HI in white matter injury. c-Jun N-terminal kinases (JNK) are important stress-responsive kinases in various forms of insults. We hypothesized that LPS-sensitized HI causes white matter injury through JNK activation-mediated neuroinflammation, BBB leakage and oligodendroglial apoptosis in the white matter of P2 rat pups.

METHODS

P2 pups received LPS (0.05 mg/kg) or normal saline injection followed by 90-min HI. Immunohistochemistry and immunoblotting were used to determine microglia activation, TNF-α, BBB damage, cleaved caspase-3, JNK and phospho-JNK (p-JNK), myelin basic protein (MBP), and glial fibrillary acidic protein (GFAP) expression. Immunofluorescence was performed to determine the cellular distribution of p-JNK. Pharmacological and genetic approaches were used to inhibit JNK activity.

RESULTS

P2 pups had selective white matter injury associated with upregulation of activated microglia, TNF-α, IgG extravasation and oligodendroglial progenitor apoptosis after LPS-sensitized HI. Immunohistochemical analyses showed early and sustained JNK activation in the white matter at 6 and 24 h post-insult. Immunofluorescence demonstrated upregulation of p-JNK in activated microglia, vascular endothelial cells and oligodendrocyte progenitors, and also showed perivascular aggregation of p-JNK-positive cells around the vessels 24 h post-insult. JNK inhibition by AS601245 or by antisense oligodeoxynucleotides (ODN) significantly reduced microglial activation, TNF-α immunoreactivity, IgG extravasation, and cleaved caspase-3 in the endothelial cells and oligodendrocyte progenitors, and also attenuated perivascular aggregation of p-JNK-positive cells 24 h post-insult. The AS601245 or JNK antisense ODN group had significantly increased MBP and decreased GFAP expression in the white matter on P11 than the vehicle or scrambled ODN group.

CONCLUSIONS

LPS-sensitized HI causes white matter injury through JNK activation-mediated upregulation of neuroinflammation, BBB leakage and oligodendrocyte progenitor apoptosis in the immature brain.

Antenatal antecedents of cognitive impairment at 24 months in extremely low gestational age newborns

BACKGROUND AND OBJECTIVES

Extremely low gestational age neonates are more likely than term infants to develop cognitive impairment. Few studies have addressed antenatal risk factors of this condition. We identified antenatal antecedents of cognitive impairment determined by the Mental Development Index (MDI) portion of the Bayley Scales of Infant Development, Second Edition (BSID-II), at 24 months corrected age.

METHODS

We studied a multicenter cohort of 921 infants born before 28 weeks of gestation during 2002 to 2004 and assessed their placentas for histologic characteristics and microorganisms. The mother was interviewed and her medical record was reviewed. At 24 months adjusted age, children were assessed with BSID-II. Multinomial logistic models were used to estimate odds ratios.

RESULTS

A total of 103 infants (11%) had an MDI <55, and 99 infants (11%) had an MDI between 55 and 69. No associations were identified between organisms recovered from the placenta and developmental delay. Factors most strongly associated with MDI <55 were thrombosis of fetal vessels (OR 3.1; 95% confidence interval [CI] 1.2, 7.7), maternal BMI >30 (OR 2.0; 95% CI 1.1, 3.5), maternal education ≤12 years (OR 3.4; 95% CI 1.9, 6.2), nonwhite race (OR 2.2; 95% CI 1.3, 3.8), birth weight z score < -2 (OR 2.8; 95% CI 1.1, 6.9), and male gender (OR 2.7; 95% CI 1.6, 4.5).

CONCLUSIONS

Antenatal factors, including thrombosis of fetal vessels in the placenta, severe fetal growth restriction, and maternal obesity, convey information about the risk of cognitive impairment among extremely premature newborns.

Increased cord serum inflammatory markers in small-for-gestational-age neonates

OBJECTIVE

The pathological picture in ischemic tissue injury shares features with the inflammatory response. Hypoxia-mediated induction of interleukin-6 (IL-6) could set in motion the mechanisms limiting inflammation in ischemia. Intrauterine growth restriction (IUGR) represents a human model of chronic fetal hypoxia. The purpose of this study was a first-time exploration to determine whether cord blood obtained at the delivery of small-for-gestational-age (SGA) infants has increased concentrations of inflammatory markers.

STUDY DESIGN

Cord blood was collected from 20 SGA (term and near-term) infants and 20 appropriate-for-gestational-age (AGA) controls. Infants exposed to maternal smoking, diabetes, maternal chronic diseases, or alcohol or drug use were excluded. Both groups had Apgar score ≥7 at 1 min with a normal cord pH (>7.25). Cord-serum cytokines and thrombopoietin (TPO) levels were measured by enzyme linked immunosorbent assay. C-reactive protein (CRP) was measured using a turbidometric immunoassay.

RESULT

SGA infants had a significantly smaller birth weight than AGA controls, with a smaller gestation age by 1 week. There were significant elevations in IL-6, tumor necrosis factor (TNF-α), CRP and TPO in the SGA compared with the AGA group, which persisted in multiple regression analysis even after gestational age was taken into account.

CONCLUSION

As hypothesized, significant increases in the cord blood concentrations of known inflammatory markers were found in SGA infants compared with the controls.