Histologic chorioamnionitis and severity of illness in very low birth weight newborns

Role of perfusion index and plethysmography variability index for predicting outcomes in neonatal sepsis

AIM

(i) To compare perfusion index (PI) and plethysmography variability index (PVI) between neonates with proven or probable sepsis versus no-sepsis, (ii) to examine an association of PI and PVI with in-hospital mortality.

METHODS

We enrolled neonates with clinically presumed sepsis. Culture-proven or probable sepsis were categorised as 'cases' and no-sepsis as 'controls'. PI and PVI were recorded hourly for 120 h and averaged in 20-time epochs (0-6 h to 115-120 h).

RESULTS

We analysed 148 neonates with sepsis (proven sepsis = 77, probable sepsis = 71) and 126 with no-sepsis. Neonates with proven/probable sepsis and no-sepsis had comparable PI and PVI values. Among 148 neonates with sepsis, 43 (29%) died. Non-survivors had significantly lower PI values than survivors (mean difference 0.21 [95% CI 0.14-0.29], p-value <0.001). PI had a significant but modest discriminative ability to identify non-survivors. However, PI did not independently predict mortality.

CONCLUSION

Neonates with proven/probable sepsis and no-sepsis had comparable PI and PVI values in the first 120 h of sepsis. PI but not PVI values were significantly lower in non-survivors than survivors. PI did not independently predict in-hospital mortality. Due to modest discriminative ability, PI should be interpreted along with other vital signs to take clinical decisions.

Changes in respiratory management and the impact on bronchopulmonary dysplasia

OBJECTIVE

Noninvasive respiratory support has reduced the need for mechanical ventilation and surfactant administration in very premature neonates. We sought to determine how the increased use of noninvasive ventilation and less surfactant instillation has impacted the development of bronchopulmonary dysplasia (BPD) using four currently used BPD definitions.

STUDY DESIGN

This is a retrospective, single-center cohort study of neonates born at less than 28 weeks gestation between 2010 and 2018. A respiratory practice change (less surfactant and more noninvasive ventilation) occurred in 2014 following participation in the Surfactant Positive Airway Pressure and Pulse Oximetry trial. Therefore, patients were divided into two epochs to compare postnatal respiratory and clinical course and BPD outcomes across four currently relevant definitions (Vermont Oxford Network, National Institute of Child Health and Human Development, Canadian, and Neonatal Research Network).

RESULTS

Clinical and demographic variables were similar between epochs. Despite significant differences in maternal and infant characteristics and clinical course, the incidence of BPD was not significantly different between the two epochs regardless of the BPD definition utilized. There was a wide range in the incidence of BPD depending on the definition used.

CONCLUSIONS

Despite decreased use of surfactant administration and invasive mechanical ventilation between the two epochs, the incidence of BPD did not change and there was wide variation depending on the definition used. A better understanding of the risk factors associated with BPD and a consensus definition is urgently needed to: 1) more accurately compare various studies, 2) help facilitate the conduct of clinical trials, and 3) enhance the development of novel therapeutic interventions to improve outcome.

Retinopathy of prematurity in infants without fetal growth restriction is decreased with the progression of acute histologic chorioamnionitis: New observation as a protective factor against retinopathy of prematurity

INTRODUCTION

IGF-1 deficiency in prenatal period is known to be a definite pathophysiology of retinopathy of prematurity(ROP), which is more frequent in infants with fetal growth restriction(FGR). Of note, recent reports demonstrated intra-amniotic inflammation(IAI) closely linked to acute histologic chorioamnionitis(acute-HCA) is associated with a decrease in intact-form of IGFBP-1, ultimately rising the probability of an increase in IGF-1. Therefore, we hypothesized ROP in preterm-infants without FGR would be decreased with the progression of acute-HCA.

METHODS

The frequency of ROP was examined in 85 singleton preterm-infants(24.5weeks ≤ gestational-age[GA] at delivery<30weeks) due to either preterm-labor and intact-membranes(PTL) or preterm premature rupture of membranes(preterm-PROM) without FGR(birth-weight<5th percentile for GA). Patients were divided according to the progression of inflammation in extra-placental membranes(EPM) and the progression of inflammation in chorionic-vessel(CV) and umbilical-cord(UC).

RESULTS

1) ROP was present in 40%(34/85) of study-population; 2) Of note, there was a significant stepwise-decrease in ROP with the progression of inflammation in EPM(inflammation-free EPM vs. inflammation restricted to CD vs. amnionitis; 55.6%[15/27]vs.39.5%[17/43]vs.13.3%[2/15]) and the progression of inflammation in CV and UC(inflammation-free CV and UC vs. inflammation restricted to CV and umbilical vessels vs. inflammation in Wharton's jelly[WJ]; 49.2%[29/59]vs.25.0%[3/12]vs.14.3%[2/14])(each-for P < 0.05, Chi-square test and each-for P < 0.01, linear-by-linear association); 3) Multiple logistic-regression analysis demonstrated amnionitis(Odds-Ratio 0.120, 95%Confidence-Interval 0.022-0.654, P = 0.014) and inflammation in WJ(Odds-Ratio 0.124, 95%Confidence-Interval 0.022-0.694, P = 0.018) were independent protective-factors against ROP.

DISCUSSION

ROP in preterm-infants due to PTL or preterm-PROM without FGR is decreased with the progression of acute-HCA. This finding may be an evidence to suggest the progression of acute-HCA is closely associated with reducing the pathophysiology of ROP.

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.

Histological chorioamnionitis and risk of pulmonary complications in preterm births: a systematic review and Meta-analysis

Histological chorioamnionitis is associated with significant adverse maternal, perinatal and long-term outcome. We performed a meta-analysis of 30 observational studies in order to clarify the association between Histological chorioamnionitis and pulmonary complications, like respiratory distress syndrome and Bronchopulmonary Dysplasia. Unadjusted data extracted from all studies showed that Histological chorioamnionitis has no effect on development of RDS (RR 0.93, 95% CI 1.08-1.67), while it increased the risk of Bronchopulmonary Dysplasia (RR 1.75, 95% CI 1.37-2.23). However, when we restricted the analysis to the studies that adjust for Gestational Age, in order to exclude the influence of prematurity, we found that HCA reduced the risk of respiratory distress syndrome (RR 0.57, CI 95% 0.35-0.93) and it did not affect the development of Bronchopulmonary Dysplasia (RR 0.99, CI 0.76-1.3). Our results confirmed a possible role of prenatal inflammation on lung maturation. However, further prospective studies with a selected population are needed, in order to clarify the role of Histological chorioamnionitis in neonatal pulmonary complications.

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.

Recurrence of Basal Plate Myofibers, with Further Consideration of Pathogenesis

OBJECTIVES

Basal plate myofibers (BPMF) may indicate morbid adherence. We assessed recurrence and clinical progression of BPMF.

METHODS

In 5 years, 135 BPMF placentas were reported. Controls were the first 50 placentas in 2009, none of which had reported BPMF.

RESULTS

32% of BPMF patients had other placentas, with a recurrence rate of 100%. Actin stains were needed for diagnosis in 117/179 cases (65%). These cases had clinical features suggestive of morbid adherence in 69/117 (59%). 23/47 (49%) of BPMF recurrences progressed in severity, 5 to hysterectomy (11%). Thinning of the basal plate, perforating vessels, gaps in the basal plate, and villi under the basal plate were observed in BPMF placentas.

CONCLUSIONS

These findings appear to validate screening for BPMF. The 100% recurrence rate suggests evaluation for a heritable factor, i.e., protease inhibitor deficiency, which may explain pre-delivery basal plate damage.

Early postnatal illness severity scores predict neurodevelopmental impairments at 10 years of age in children born extremely preterm

OBJECTIVE

A neonatal illness severity score, The Score for Neonatal Acute Physiology-II (SNAP-II), predicts neurodevelopmental impairments at two years of age among children born extremely preterm. We sought to evaluate to what extent SNAP-II is predictive of cognitive and other neurodevelopmental impairments at 10 years of age.

STUDY DESIGN

In a cohort of 874 children born before 28 weeks of gestation, we prospectively collected clinical, physiologic and laboratory data to calculate SNAP-II for each infant. When the children were 10 years old, examiners who were unaware of the child's medical history assessed neurodevelopmental outcomes, including neurocognitive, gross motor, social and communication functions, diagnosis and treatment of seizures or attention deficit hyperactivity disorder (ADHD), academic achievement, and quality of life. We used logistic regression to adjust for potential confounders.

RESULTS

An undesirably high SNAP-II (⩾30), present in 23% of participants, was associated with an increased risk of cognitive impairment (IQ, executive function, language ability), adverse neurological outcomes (epilepsy, impaired gross motor function), behavioral abnormalities (attention deficit disorder and hyperactivity), social dysfunction (autistic spectrum disorder) and education-related adversities (school achievement and need for educational supports. In analyses that adjusted for potential confounders, Z-scores ⩽-1 on 11 of 18 cognitive outcomes were associated with SNAP-II in the highest category, and 6 of 18 were associated with SNAP-II in the intermediate category. Odds ratios and 95% confidence intervals ranged from 1.4 (1.01, 2.1) to 2.1 (1.4, 3.1). Similarly, 2 of the 8 social dysfunctions were associated with SNAP-II in the highest category, and 3 of 8 were associated with SNAP-II in the intermediate category. Odds ratios and 95% confidence intervals were slightly higher for these assessments, ranging from 1.6 (1.1, 2.4) to 2.3 (1.2, 4.6).

CONCLUSION

Among very preterm newborns, physiologic derangements present in the first 12 postnatal hours are associated with dysfunctions in several neurodevelopmental domains at 10 years of age. We are unable to make inferences about causality.

Continuous noninvasive monitoring in the neonatal ICU

PURPOSE OF REVIEW

Standard hemodynamic monitoring such as heart rate and systemic blood pressure may only provide a crude estimation of organ perfusion during neonatal intensive care. Pulse oximetry monitoring allows for continuous noninvasive monitoring of hemoglobin oxygenation and thus provides estimation of end-organ oxygenation. This review aims to provide an overview of pulse oximetry and discuss its current and potential clinical use during neonatal intensive care.

RECENT FINDINGS

Technological advances in continuous assessment of dynamic changes in systemic oxygenation with pulse oximetry during transition to extrauterine life and beyond provide additional details about physiological interactions among the key hemodynamic factors regulating systemic blood flow distribution along with the subtle changes that are frequently transient and undetectable with standard monitoring.

SUMMARY

Noninvasive real-time continuous systemic oxygen monitoring has the potential to serve as biomarkers for early-organ dysfunction, to predict adverse short-term and long-term outcomes in critically ill neonates, and to optimize outcomes. Further studies are needed to establish values predicting adverse outcomes and to validate targeted interventions to normalize abnormal values to improve outcomes.

Chorioamnionitis appears not to be a Risk Factor for Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-Analysis

The contribution of chorioamnionitis (CA) to mortality and morbidity in preterm infants is difficult to assess because observational studies frequently present significant differences in baseline characteristics of the infants exposed or non-exposed to CA. In an attempt to perform a thorough assessment of the possible association between CA and patent ductus arteriosus (PDA) in preterm infants, we conducted a meta-analysis in which adjusted odds ratios (ORs) were pooled and we analyzed the effects of potential confounders, such as gestational age (GA) or birth weight (BW). We identified 45 relevant studies (27186 patients, 7742 CA cases). Random effects meta-analysis of crude ORs showed a significant positive association between CA and PDA (OR 1.352, 95% CI 1.172 to 1.560). Adjusted ORs were reported in 11 studies (19577 infants). Meta-analysis of these studies showed a significant negative association between CA and PDA (OR 0.802, 95% CI 0.751 to 0.959). Meta-regression showed that the differences in GA or BW between the CA-exposed and non-exposed groups were significantly correlated with the effect size of the association between PDA and CA. In conclusion, our study confirms that confounders need to be taken into account when assessing the association between CA and clinical outcomes in preterm infants.

Neonatal risk mortality scores as predictors for health-related quality of life of infants treated in NICU: a prospective cross-sectional study

PURPOSE

To determine the relationship of Apgar scores, gestational age and neonatal risk mortality scores to health-related quality of life (HRQoL) for infants at the age of 8 months treated after birth in neonatal intensive care unit (NICU).

METHODS

All surviving infants treated in two-third level NICUs in Rijeka, Croatia (from August 2013 to August 2014) were included in this prospective, cross-sectional study. For all neonates, the Score for Neonatal Acute Physiology (SNAP), SNAP with Perinatal Extension (SNAP-PE) and their simplified modifications (SNAP II and SNAP-PE II) were calculated. At the corrected age of 8 months, the Pediatric Quality of Life Questionnaire (PedsQL)-infant scale-was completed by parents of surviving infants. Multiple regression analysis was performed in order to assess the value of neonatal risk mortality scores, Apgar scores and gestational age as possible predictors of HRQoL, measured by questionnaire score.

RESULTS

A strong correlation has been found between SNAP and 5-min Apgar scores to HRQoL. A positive correlation was also found between gestational age and HRQoL.

CONCLUSION

SNAP and 5-min Apgar scores are important outcome indicators, can aid clinicians' and parents' decision making on the benefits and burdens of acute medical interventions and help determine quantities of medical treatment. Educated medical staff, effective and efficient medical treatment and a high quality of care which prevent adverse events in the first minute of life should be a priority in efforts to improve the future quality of life.

A Systematic Review: The Utility of the Revised Version of the Score for Neonatal Acute Physiology Among Critically Ill Neonates

The revised version of the Score for Neonatal Acute Physiology (SNAP-II) has been used across all birth weights and gestational ages to measure the concept of severity of illness in critically ill neonates. The SNAP-II has been operationalized in various ways across research studies. This systematic review seeks to synthesize the available research regarding the utility of this instrument, specifically on the utility of measuring severity of illness sequentially and at later time points. A systematic review was performed and identified 35 research articles that met inclusion and exclusion criteria. The majority of the studies used the SNAP-II instrument as a measure of initial severity of illness on the first day of life. Six studies utilized the SNAP-II instrument to measure severity of illness at later time points and only 2 studies utilized the instrument to prospectively measure severity of illness. Evidence to support the use of the SNAP-II at later time points and prospectively is lacking and more evidence is needed.

Chorioamnionitis and Patent Ductus Arteriosus: A Systematic Review and Meta-Analysis

Background

Chorioamnionitis has recently been reported as a risk factor for various neonatal diseases, including cerebral palsy, bronchopulmonary dysplasia, and necrotizing enterocolitis, but its effect on patent ductus arteriosus (PDA) is unclear. We performed a systematic review and meta-analysis to evaluate the effect of chorioamnionitis on PDA.

Methods

We searched PubMed, EMBASE, Cochrane Library, and KoreaMed databases using the terms: “intrauterine infection” or “maternal infection” or “antenatal infection” or “chorioamnionitis” or “placenta inflammation” or “placenta pathology” or “neonatal outcome” or “neonatal morbidity” or “PDA or patent ductus arteriosus” or “ductus arteriosus,” and “prematurity” or “very low birth weight infant.” Studies were included if they were randomized controlled trials, case–control studies, or cohort studies that included information relating to chorioamnionitis and PDA.

Results

Among 1,571 studies, a total of 23 studies (17,708 cases) were included in the meta-analysis to analyze the relationship between chorioamnionitis and PDA, except one study that only included PDA requiring surgical ligation. The association between chorioamnionitis and PDA was statistically significant (odds ratio [OR] 1.43; 95% confidence interval [CI] 1.19, 1.72; P < 0.0001). In subgroup analysis, clinical chorioamnionitis was not associated with PDA (OR 1.28; 95% CI 1.00, 1.64, 1.790; P = 0.05), whereas histologic chorioamnionitis (OR 1.54; 95% CI 1.10, 2.15; P = 0.01) and chorioamnionitis diagnosed from both clinical and histologic findings (OR 1.75; 95% CI 1.07, 2.86; P = 0.03) showed significant associations with PDA. Chorioamnionitis did not increase the risk of PDA requiring surgical ligation (OR 1.23; 95% CI 0.69, 2.17; P = 0.48), and antenatal steroid use reduced the risk of PDA (OR 0.62; 95% CI 0.42, 0.90; P = 0.01) after chorioamnionitis.

Conclusions

The results from this meta-analysis support an association between maternal chorioamnionitis and PDA in offspring.

Reference values of perfusion indices in hemodynamically stable newborns during the early neonatal period

We aimed to determine reference values of perfusion index (PI) in healthy newborns during the early neonatal period. Preductal (right hand) and postductal (foot) PI values were assessed during the first 5 days of life by using a new generation pulse oximetry. A total of 241 newborn infants (196 [81.3 %] term and 45 [18.7 %] preterm) were enrolled to the study. On the first day, in term infants, the median (interquartile range [IQR]) preductal and postductal PI were 1.35 (1.02-1.91) and 0.88 (0.62-1.22), respectively (p = 0.001). These values were 0.88 (0.60-1.26) and 0.61 (0.35-0.92) in preterm infants, with the same respect (p = 0.001). From the first to third days, preductal PI remained significantly higher than the postductal PI (p < 0.001, for all comparisons). Both preductal and postductal PI of term newborns were significantly higher than those of preterm infants (p < 0.001, for both comparisons). These differences in PI disappeared on the fifth day of life. Conclusion PI values which reflect peripheral perfusion seem to reach to a steady state on the fifth day of life following physiological maturation.

Chorioamnionitis in the pathogenesis of brain injury in preterm infants

Chorioamnionitis (or placental infection) is suspected to be a risk factor for brain injury in premature infants. The suggested association between chorioamnionitis and cystic periventricular leukomalacia and cerebral palsy is uncertain because of the variability of study designs and definitions of chorioamnionitis. Improvements in neonatal intensive care may have attenuated the impact of chorioamnionitis on brain health outcomes. Large multicenter studies using rigorous definitions of chorioamnionitis on placental pathologies and quantitative magnetic resonance techniques may offer the optimal way to clarify the complex role of chorioamnionitis in modifying brain health and long-term outcomes.

Antibiotic Therapy for Premature Rupture of Membranes and Preterm Labor and Effect on Fetal Outcome

In Germany almost 10 % of children are born before the end of 37th week of gestation. In at least one quarter of these cases, ascending infection of the vagina plays a causative role, particularly during the early weeks of gestation. If, in addition to the decidua, the amniotic membrane, amniotic fluid and the umbilical cord are also affected, infection not only triggers uterine contractions and premature rupture of membranes but also initiates a systemic inflammatory reaction on the part of the fetus, which can increase neonatal morbidity. Numerous studies and meta-analyses have found that antibiotic therapy prolongs pregnancy and reduces neonatal morbidity. No general benefit of antibiotic treatment was found for premature uterine contractions. But it is conceivable that a subgroup of pregnant women would benefit from antibiotic treatment. It is important to identify this subgroup of women and offer them targeted treatment. This overview summarizes the current body of evidence on antibiotic treatment for impending preterm birth and the effect on neonatal outcomes.

Histological chorioamnionitis: effects on premature delivery and neonatal prognosis

BACKGROUND

Chorioamnionitis is closely related to premature birth and has negative effects on neonatal morbidity and mortality.

METHODS

In this prospective study, 43 mothers who delivered earlier than 35 gestational weeks and their 57 infants were evaluated clinically and with laboratory findings. Placentas and umbilical cords were investigated histopathologically for chorioamnionitis and funisitis.

RESULTS

The overall frequency of clinical and histological chorioamnionitis (HCA) was 8.3% and 23.2%, respectively. The frequency of HCA was 47.3% and 83.3% in mothers delivered <32 weeks and <30 weeks, respectively. Maternal demographic and clinical findings and also leukocyte and C-reactive protein values were not indicative of HCA. Infants of mothers with HCA had significantly lower Apgar scores together with higher SNAP-PE-II and CRIB scores. These infants had increased mechanical ventilator and surfactant requirements, higher incidences of patent ductus arteriosus, early sepsis, and bronchopulmonary dysplasia, and higher mortality rates. The effect of HCA on neonatal morbidity and mortality was more prominent than the effect of low birthweight and lower gestational age.

CONCLUSION

Chorioamnionitis not only causes premature deliveries, but is also associated with neonatal complications and increased mortality. Clinical findings and infectious markers in mother or infant do not predict the diagnosis of histological chorioamnionitis. Therefore, placental histopathology may have a role in predicting neonatal outcome in premature deliveries, especially those below 30 weeks.

Total plasma protein in very preterm babies: prognostic value and comparison with illness severity scores

Objective

We aimed to investigate the predictive value for severe adverse outcome of plasma protein measurements on day one of life in very preterm infants and to compare total plasma protein levels with the validated illness severity scores CRIB, CRIB-II, SNAP-II and SNAPPE-II, regarding their predictive ability for severe adverse outcome.

Methods

We analyzed a cohort of infants born at 24–31 weeks gestation, admitted to the tertiary intensive care unit of a university hospital over 10.5 years. The outcome measure was “severe adverse outcome” defined as death before discharge or severe neurological injury on cranial ultrasound. The adjusted odd ratio (aOR) and 95% confidence interval (95% CI) of severe adverse outcome for hypoproteinemia (total plasma protein level <40 g/L) was calculated by univariate and multivariate analyses. Calibration (Hosmer-Lemeshow goodness-of-fit) was performed and the predictive ability for severe adverse outcome was assessed for total plasma protein and compared with CRIB, CRIB-II, SNAP-II and SNAPPE-II, by calculating receiver operating characteristic (ROC) curves and their associated area under the curve (AUC).

Results

761 infants were studied: 14.4% died and 4.1% survived with severe cerebral ultrasound findings. The aOR of severe adverse outcome for hypoproteinemia was 6.1 (95% CI 3.8–9.9). The rank order for variables, as assessed by AUCs and 95% CIs, in predicting outcome was: total plasma protein [0.849 (0.821–0.873)], SNAPPE-II [0.822 (0.792–0.848)], CRIB [0.821 (0.792–0.848)], SNAP-II [0.810 (0.780–0.837)] and CRIB-II [0.803 (0.772–0.830)]. Total plasma protein predicted severe adverse outcome significantly better than CRIB-II and SNAP-II (both p<0.05). Calibration for total plasma protein was very good.

Conclusions

Early hypoproteinemia has prognostic value for severe adverse outcome in very preterm, sick infants. Total plasma protein has a predictive performance comparable with CRIB and SNAPPE-II and greater than other validated severity scores.

Predictive value of clinical chorioamnionitis in extremely premature infants

BACKGROUND

Clinical chorioamnionitis and histological chorioamnionitis are important risk factors for neonatal complications and neurodevelopmental impairment in premature infants. It is unclear, however, whether a diagnosis of clinical chorioamnionitis is sufficient to establish a diagnosis of histological chorioamnionitis. The aim of this study was to evaluate the predictive value of clinical chorioamnionitis in the diagnosis of histological chorioamnionitis in extremely premature infants.

METHODS

This study was a secondary analysis of data from the Neonatal Research Network in Japan, a population-based cohort study aimed at identifying the clinical characteristics and morbidity of very low-birthweight infants. Data for extremely premature infants <28 weeks' gestational age from 2003 to 2007, were used. Subset analysis investigated positive predictive value by gestational age.

RESULTS

Of the 2470 infants analyzed, 786 were diagnosed with clinical chorioamnionitis and 1129 with histological chorioamnionitis. The positive predictive value of clinical chorioamnionitis for histological chorioamnionitis was 86.6% (681/786; 95% confidence interval [CI]: 84.4-88.6%), sensitivity was 60.3% (681/1129; 95%CI: 58.8-61.7%), and specificity was 92.2% (1236/1341; 95%CI: 90.9-93.3%). In subset analysis, the positive predictive value was particularly high at 23 weeks of gestation (89.1%; 115/129), with sensitivity of 65.3% (115/176) and specificity of 89.6% (120/134).

CONCLUSIONS

The finding that clinical chorioamnionitis is a useful predictor of histological chorioamnionitis provides important insights into the relationship between these two diagnoses, and has important implications in determining the appropriate timing of delivery of extremely premature infants.

Chorioamnionitis and lung injury in preterm newborns

There is a strong evidence that histologic chorioamnionitis is associated with a reduction of incidence and severity of respiratory distress syndrome (RDS). Short-term maturational effects on the lungs of extremely premature infants seem to be, however, accompanied by a greater susceptibility of the lung, eventually contributing to an increased risk of bronchopulmonary dysplasia (BPD). Genetic susceptibility to BPD is an evolving area of research and several studies have directly related the risk of BPD to genomic variants. There is a substantial heterogeneity across the studies in the magnitude of the association between chorioamnionitis and BPD, and whether or not the association is statistically significant. Considerable variation is largely dependent on differences of inclusion and exclusion criteria, as well as on clinical and histopathological definitions. The presence of significant publication bias may exaggerate the magnitude of the association. Controlling for publication bias may conduct to adjusted results that are no longer significant. Recent studies generally seem to confirm the effect of chorioamnionitis on RDS incidence, while no effect on BPD is seen. Recent data suggest susceptibility for subsequent asthma to be increased on long-term followup. Additional research on this field is needed.

Predictors of bronchopulmonary dysplasia

Although significant advances in respiratory care have been made in neonatal medicine, bronchopulmonary dysplasia (BPD) remains the most common serious pulmonary morbidity in premature infants. The development of BPD is the result of the complex interactions between multiple perinatal and postnatal factors. Early identification of infants at the most risk of developing BPD through the use of estimators and models may allow a targeted approach at reducing BPD in the future.

Noninvasive monitoring by photoplethysmography

The photoplethysmogram (PPG) is a noninvasive circulatory signal related to the pulsatile volume in tissue and is displayed by many pulse oximeters. The PPG is similar in appearance to the invasive arterial waveform, but is noninvasive and ubiquitous in hospitals. There is increasing interest in seeking circulatory information from the PPG and developing techniques for a wide variety of novel applications. This article addresses the basic physics of photoplethysmography, physiologic principles behind pulse oximetry operation, and recent technological advances in the usefulness of the PPG waveform to assess microcirculation and intravascular fluid volume monitoring during intensive care.

Perinatal outcome and placental histological characteristics: a single-center study

OBJECTIVE

Placental pathology assists in characterizing the antenatal environment and may provide information about the baby's subsequent development. We aim to assess whether histological patterns of placenta are associated with an increased risk of perinatal diseases and to evaluate how different patterns of placental dysfunction can affect the neurodevelopmental outcome.

METHODS

We analyzed the histopathological characteristics of 105 singleton placentas from infants born between 23 and 31 weeks of gestation and we assessed pair-wise correlations with perinatal diseases. Estimated relative risks were calculated from odds ratios.

RESULTS

Histological chorioamnionitis (CA group) was detected on 51 of 100 placentas tested. Lesions of uteroplacental circulation (abruption, infarction or thrombosis, perivillous fibrin deposition, syncytial knots; vasculopathy group) were detected on 29. 25 normal placentas served as controls. The incidence of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus (PDA) was higher in CA than in control group. The risk of developing retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH) and PDA was higher in CA than in vasculopathy group.

CONCLUSIONS

At low gestational age CA, rather than placental lesions of vasculopathy, negatively impacts perinatal outcome. Clinical significance of histologic vasculopathy remains questionable. Other pathophysiological mechanisms than those associated with placental changes may occur following dysfunction of uteroplacental circulation.

First day of life reference values for pleth variability index in spontaneously breathing term newborns

BACKGROUND

The perfusion index (PI), derived from the pulse oximetry signal, has been shown to be an accurate predictor for identifying high illness severity in neonates. The plethysmographic variability index (PVI) is a measure of the dynamic change in PI occurring during a complete respiratory cycle.

OBJECTIVES

The aim of this study was to establish the reference range of PVI in spontaneously breathing term newborns.

METHODS

PI and PVI values were assessed in 242 term newborns during the first day of life.

RESULTS

The median PVI value on the first day of life was 20% [95% confidence interval (CI) for the mean 19-20%; inter-quartile range 15 (95% CI 15-16) - 24 (95% CI 23-24)]. The 10th and 90th percentile cutoff values were 12% (95% CI 11-12) and 28% (95% CI 27-29), respectively, with the 97.5th percentile of 35% (95% CI 34-38). PVI was also significantly influenced by the behavioral status of the newborn, and was positively correlated with PI and pulse rate, while it was inversely correlated with oxygen saturation (p < 0.0001).

CONCLUSIONS

Our findings suggest: (1) evaluation of PVI values is an easily applicable, noninvasive procedure for monitoring early postnatal respiratory changes in newborns, and (2) the feasibility of a noninvasive pulse-oximeter postnatal screening for early identification of adverse neonatal cardiorespiratory outcomes.

Bronchopulmonary Dysplasia: Development and Progression in the Neonatal Intensive Care Unit

Advances in neonatology have led to increased survival at younger gestational ages. These advances have included the ability to provide and titrate oxygen, improved modalities of assisted ventilation, improved nutritional and environmental support, and surfactant therapy. As a result of increasing survival of these immature infants, bronchopulmonary dysplasia (BPD) has become a consistent outcome despite improvements in technology. Varying definitions of BPD have emerged in an effort to best identify infants at risk for long-term adverse outcome and those who might benefit most from preventive therapies. Underlying abnormal pulmonary development of extremely preterm infants in the face of exposure to oxygen, assisted ventilation and inflammation make this a complex, multifactorial disease. Recent focus has been directed at preventing and treating inflammation. Efforts to minimize the inflammatory process include avoiding hyperoxia, minimizing injury from assisted ventilation, and preventing and treating postnatal infections. Additional therapies to modulate inflammation, such as steroid therapy or inhaled nitric oxide, need further investigation of both short- and long-term outcomes before routine use can be recommended.

Neonatal and neurodevelopmental outcomes of very low birth weight infants with histologic chorioamnionitis

OBJECTIVE

To determine survival and neurodevelopmental outcomes at 18 months corrected age among very low birth weight infants ≤ 32 weeks gestation with histologic chorioamnionitis.

STUDY DESIGN

Observational, regionalized, single-center cohort study with prospective follow-up.

RESULTS

Of the 628 infants meeting the selection criteria, 303 (48%) were born to mothers with evidence of histologic chorioamnonitis. Neonates with histologic chorioamnonitis were of lower gestational age and birth weight. On univariate analysis, they were more likely to have hypotension, bronchopulmonary dysplasia, severe intraventricular hemorrhage, severe retinopathy of prematurity, early-onset sepsis, and death. Infants with histologic chorioamnonitis were more likely to have any neurodevelopmental impairment, specifically, mental delay with a lower mental developmental index. When adjusting for perinatal variables, histologic chorioamnonitis had a protective effect on mortality rates (adjusted OR = 0.44, 95% CI: 0.24-0.8; P = .01; n = 619), had a nonsignificant effect on neurodevelopmental impairment (adjusted odds ratio = 1.33, 95% CI: 0.82-2.17; P = .25; n = 496), and was associated with a 4-point lower mental developmental index at 18-months follow-up (adjusted difference -3.93, 95% CI: -7.52 to -0.33; P = .03; n = 496).

CONCLUSIONS

Although infants with histologic chorioamnonitis were at an increased risk for death and neurodevelopmental impairment, after multivariate analyses, histologic chorioamnonitis was not associated with adverse long-term outcomes. Results suggest fetal protection from treatment-responsive maternal infection and inflammation.

Moderate postnatal hyperoxia accelerates lung growth and attenuates pulmonary hypertension in infant rats after exposure to intra-amniotic endotoxin

To determine the separate and interactive effects of fetal inflammation and neonatal hyperoxia on the developing lung, we hypothesized that: 1) antenatal endotoxin (ETX) causes sustained abnormalities of infant lung structure; and 2) postnatal hyperoxia augments the adverse effects of antenatal ETX on infant lung growth. Escherichia coli ETX or saline (SA) was injected into amniotic sacs in pregnant Sprague-Dawley rats at 20 days of gestation. Pups were delivered 2 days later and raised in room air (RA) or moderate hyperoxia (O₂, 80% O₂ at Denver's altitude, ∼65% O₂ at sea level) from birth through 14 days of age. Heart and lung tissues were harvested for measurements. Intra-amniotic ETX caused right ventricular hypertrophy (RVH) and decreased lung vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein contents at birth. In ETX-exposed rats (ETX-RA), alveolarization and vessel density were decreased, pulmonary vascular wall thickness percentage was increased, and RVH was persistent throughout the study period compared with controls (SA-RA). After antenatal ETX, moderate hyperoxia increased lung VEGF and VEGFR-2 protein contents in ETX-O₂ rats and improved their alveolar and vascular structure and RVH compared with ETX-RA rats. In contrast, severe hyperoxia (≥95% O₂ at Denver's altitude) further reduced lung vessel density after intra-amniotic ETX exposure. We conclude that intra-amniotic ETX induces fetal pulmonary hypertension and causes persistent abnormalities of lung structure with sustained pulmonary hypertension in infant rats. Moreover, moderate postnatal hyperoxia after antenatal ETX restores lung growth and prevents pulmonary hypertension during infancy.

Perfusion index variations in clinically and hemodynamically stable preterm newborns in the first week of life

BACKGROUND

The perfusion index, derived from the pulse oximeter signal, seems to be an accurate predictor for high illness severity in newborns. The aim of this study was to determine the perfusion index values of clinically and hemodynamically stable preterm newborns in the first week of life.

METHODS

Perfusion index recordings were performed on the first, third and seventh day of life on 30 preterm newborns. Their state of health was assessed according to clinical and behaviour evaluation and to the Score for Neonatal Acute Physiology.

RESULTS

The median(interquartile range) perfusion index values were 0.9(0.6) on the first, 1.2(1.0) on the third, and 1.3(0.9) on the seventh day, with a significant increase between the first and the third day.

CONCLUSIONS

Perfusion index proved to be an easily applicable, non-invasive method for monitoring early postnatal changes in peripheral perfusion. Its trend during the first week of life suggests that its clinical application should take age into account. Further studies are needed to obtain reference perfusion index values from a larger sample of preterm newborns, to identify specific gestational age-related cut-off values for illness and to test the role of perfusion index in monitoring critically ill neonates.

The association between maternal body mass index and severity of neonatal illness in very low birth weight infants

OBJECTIVE

To determine the effect of maternal body mass index (BMI) and pregnancy weight gain on neonatal illness severity in very low birth weight infants.

METHODS

Cohort study of infants with birth weight less than 1500 g at a level 3 Neonatal Intensive Care Unit from July 2003 to July 2005, n = 301. The main outcome included neonatal illness severity, as measured by the Score for Neonatal Acute Physiology (SNAP). SNAP was investigated in relationship to maternal BMI and pregnancy weight gain. Statistical analysis included Pearson correlation, ANOVA and multivariable linear regression.

RESULTS

At delivery and pre-pregnancy, 49 and 54% of mothers were overweight, respectively. Black mothers were more likely to be overweight with less pregnancy weight gain compared with white mothers. After controlling for confounding variables, maternal pre-pregnancy BMI, pregnancy BMI and weight gain were not associated with neonatal illness.

CONCLUSIONS

In our population of very low birth weight infants, maternal BMI was not associated with neonatal illness severity. Black mothers had higher pre-pregnancy BMI and less weight gain than white mothers. The significance of these differences needs further exploration.

Histologic chorioamnionitis, fetal involvement, and antenatal steroids: effects on neonatal outcome in preterm infants

OBJECTIVE

The objective of the study was to study the effects of histologic chorioamnionitis (HC) with or without fetal involvement and antenatal steroid (AS) exposure on neonatal outcome in a prospective cohort of preterm infants.

STUDY DESIGN

The clinical characteristics and placental histology were prospectively collected in 301 infants born at a gestational age 32.0 weeks or less in the Erasmus University Medical Center.

RESULTS

In univariable analyses, HC without fetal involvement (n=53) was associated with decreased severe respiratory distress syndrome (RDS) (11% vs 28%; P<.05), whereas HC with fetal involvement infants (n=68) had more necrotizing enterocolitis (9% vs 2%; P<.05), intraventricular hemorrhage (IVH) (25% vs 12%; P<.05), and neonatal mortality (19% vs 9%; P<.05). In HC without fetal involvement infants, AS reduced the incidences of RDS (43% vs 85%; P<.05) and IVH (5% vs 39%; P<.01). In multivariable analyses, HC without fetal involvement was associated with decreased severe RDS (odds ratio, 0.22; 95% confidence interval, 0.05-0.93; P<.05) and increased early-onset sepsis (odds ratio, 2.22; 95% confidence interval, 1.02-4.83; P<.05).

CONCLUSION

In a prospective cohort of preterm infants, multivariable analyses reveal only a modest association between histologic chorioamnionitis and neonatal outcome.

Subclinical histologic chorioamnionitis and related clinical and laboratory parameters in preterm deliveries

BACKGROUND

Histologic chorioamnionitis (HCA) is associated with preterm delivery and with neonatal morbidity and mortality. Because HCA is usually subclinical, histologic examination of the placenta is essential for confirmatory diagnosis. In the present study, the correlations between subclinical HCA and relevant clinical and laboratory parameters were analyzed.

METHODS

This was a retrospective study. We reviewed the placental histopathologic findings and the charts of patients who were admitted to our neonatal intensive care unit after delivery and their mothers between January 2007 and March 2008. A total of 77 preterm infants [gastational age (GA): 32.2 3.4 weeks, birth weight (BW): 1718 +/- 554 g] were categorized as group A with histologic evidence of placental inflammation (n=27) or group B without histologic evidence of placental inflammation (n=50). Placental histology was studied to identify the presence of inflammatory states such as chorioamnionitis, funisitis and deciduitis. Laboratory parameters including complete blood count, differential count, and C-reactive protein (CRP) level of mothers and initial arterial blood gas, glucose Level and mean blood pressure of the infants were documented. Gestational age, Apgar score, history of prolonged premature rupture of membrane (prolonged PROM), gestational diabetes mellitus, meconium-stained amniotic fluid, pregnancy-induced hypertension and signs of pre-eclampsia were also collected as clinical parameters. All data were analyzed using independent t tests and Fisher's exact test, as appropriate.

RESULTS

Group A newborns had a significantly lower gestational age (30.8 +/- 4.1 weeks vs. 33.0 +/- 2.6 weeks, p < 0.05) and higher CRP level (0.56 +/- 0.92 mg/dL vs. 0.12 +/- 0.14 mg/dL, p < 0.05), together with higher maternal WBC count (13,002 +/- 4344/microL vs. 10,850 +/- 3722/microL, p < 0.05) and higher rate of prolonged PROM [14/27 (51.85%) vs. 8/37 (21.62%), p < 0.05] compared with group B newborns.

CONCLUSION

We found that HCA was significantly correlated with lower gestational age, higher CRP level of preterm infants, higher maternal WBC count, and a higher rate of prolonged PROM. Our results demonstrate a significant association between HCA with an elevated CRP level in preterm infants. These findings further confirmed the association between maternal inflammation and preterm deliveries.

Recurrent otitis media with effusion in preterm infants with histologic chorioamnionitis--a 3 years follow-up study

BACKGROUND

Recurrent otitis media with effusion (OME) is a leading cause of acquired hearing loss in childhood. Histological chorioamnionitis (HCA) is an important cause of preterm delivery and neonatal morbidity and mortality. Here, we tested the hypothesis of an association between recurrent OME during the first 3 years of life and HCA in very low birth weight (VLBW) infants.

METHODS

A total of 110 randomly selected VLBW preterm newborns with HCA and 135 gestational age and gender-matched, HCA-negative VLBW infants were evaluated prospectively during the first 3 years of life for the presence of OME, as diagnosed on the basis of otoscopy, type B or C tympanogram, ipsilateral absence of transient evoked otoacoustic emissions responses, and ipsilaterally increased threshold at diagnostic auditory brain responses evaluation. Potential risk factors for OME were also examined in the two groups.

RESULTS

The HCA-positive infants showed a approximately six times higher frequency of recurrent OME (P<0.0001), increased frequency (>5/yr) of clinical otitis media episodes (P=0.000020), approximately five times higher frequency of adenoid hypertrophy (P<0.00001), a significant seasonal pattern of birth with autumn predominance (P<0.00001), and the first OME occurred earlier (P<0.0001), as compared to the HCA-negative counterparts. Recurrent OME was significantly associated with HCA (O.R.=17.76, 95% CI: 8.98-35.13, P<0.00001), adenoid hypertrophy (O.R.=9.96, 95% CI: 5.17-19.18, P<0.00001), frequency of acute otitis episodes >5/yr (O.R.=8.91, 95% CI: 1.96-40.41, P=0.0005), and birth in autumn (O.R.=5.58, 95% CI: 2.79-11.12, P<0.00001).

CONCLUSIONS

These findings indicate that HCA is a previously unrecognized risk factor for the development of recurrent bilateral OME in VLBW preterm infants during the first 3 years of life.

Maternal pulse oximetry perfusion index as a predictor of early adverse respiratory neonatal outcome after elective cesarean delivery

OBJECTIVE

Evidence suggests increased morbidity, in particular early neonatal respiratory complications, in newborns from elective cesarean section compared with those from vaginal delivery. No reliable maternal predictors of adverse neonatal outcome at elective cesarean section are known. Here, we prospectively tested the hypothesis that a low maternal perfusion index at the baseline phase (i.e., preanesthesia) of the elective cesarean section is a predictor of early adverse neonatal respiratory outcome.

DESIGN

Prospective cohort study.

SETTING

Operating and delivery rooms of a public health hospital with a tertiary-level neonatal intensive care unit.

PATIENTS

Forty-four healthy pregnant women with no known risk factors undergoing elective cesarean section at term gestation.

INTERVENTIONS

Elective cesarean section was divided into nine phases. Analysis of pulse oximetry-derived signals (perfusion index, pulse rate, and oximetry) and systolic, diastolic, and differential blood pressure were recorded. Maternal arterial and venous newborn cord blood gas analyses and placental histology were evaluated.

MEASUREMENTS AND MAIN RESULTS

Early respiratory complications (transient tachypnea of the newborn, n = 5; respiratory distress syndrome, n = 1) were observed in 13.6% (6 of 44) of the newborns. A maternal perfusion index < or = 1.9 (lower quartile) during the preanesthesia phase of the elective cesarean section was an independent predictor of early adverse neonatal respiratory outcome (odds ratio 68.0, 95% confidence interval 6.02-767.72; p < .0001).

CONCLUSIONS

A decreased perfusion index value in the preanesthesia phase of elective cesarean section is a maternal predictor of increased neonatal morbidity and is significantly related to subclinical placental inflammatory disease. These observations suggest the feasibility of a noninvasive pulse oximeter prenatal screening of the high-risk fetus/newborn in elective cesarean section.

Placental histopathology in the extremely low birth weight infants

Our objective was to evaluate the placental histopathology (PH) in extremely low birth weight infants (ELBW, birth weight < 1000 g) and to determine if placental histopathological findings are associated with neonatal mortality in them. The PH of all ELBW infants (gestational age 23-30 weeks) born during a 3-year study period was prospectively evaluated and compared with term infants (gestational age > or = 37 weeks). Additionally PH of ELBW infants who expired within 28 days of life was compared with those who survived beyond 28 days. Student's t test, chi(2) test and Pearson's correlation coefficient tests were utilized for data analysis. The occurrences of placental infection (chorioamnionitis, HCA), umbilical cord inflammation (funisitis, vasculitis, and subacute necrotizing funisitis, analyzed collectively as HFV), and abruption were higher in ELBW (n = 105) compared to term infants (n = 61, p = 0.001, 0.0002, and 0.0002, respectively). Placental findings did not differ between the surviving (n = 71) and nonsurviving (n = 51) ELBW infants. Birth weight and gestational age were higher in the surviving group (p = 0.003 and 0.001, respectively). Placental abruption was found more commonly in the presence of HCA and HFV in ELBW infants as opposed to maternal hypertension in term infants. All ELBW placentas with HFV had concomitant findings of HCA whereas only 42% of ELBW placentas with HCA had findings of HFV compared to 24% in term infants (p = 0.09). There was a weak inverse correlation between HCA and birth weight in all (r = - 0.3, p = 0.01) but not in ELBW infants (r = 0.2, p = 0.07). We conclude that placental and umbilical cord inflammation and placental abruption are more commonly present in ELBW compared to term infants. However, these findings do not contribute to neonatal mortality in ELBW infants. Forty-two percent of placental (maternal) inflammation cases have concomitant cord (fetal) inflammation in ELBW infants. Finally HCA correlates inversely with birth weight in neonates.

Early dynamic changes in pulse oximetry signals in preterm newborns with histologic chorioamnionitis

OBJECTIVE

No reliable clinical markers of histologic chorioamnionitis (HCA), a major and often subclinical cause of prematurity leading to high neonatal morbidity and mortality, are available to date. Increasing evidence indicates myocardial dysfunctions in affected fetuses and newborns. We sought to assess the value of nonlinear dynamics from pulse oximetry signals in identifying affected newborns.

DESIGN

Prospective case-control study.

SETTING

Tertiary level neonatal intensive care unit, Brindisi Hospital.

PATIENTS AND INTERVENTION

Pulse oximetry-derived signals (pulse rate, oxygen saturation, and perfusion index), recorded within the first 1.5 hrs of life, were analyzed for 110 very low-birth-weight infants, of whom 54 had histopathological evidence of HCA.

MEASUREMENTS AND MAIN RESULTS

Four different time series parameters were determined for nonlinear dynamical (NLD) analysis. Significantly decreased Lempel-Ziv, Lyapunov largest exponent, and correlation dimension, with significantly increased Hurst values for heart rate and perfusion index (p < .00001), were observed in newborns with HCA. Heart rate Lempel-Ziv </=0.218 showed 100% sensitivity (95% confidence interval, 98.8-100) and 100% specificity (95% confidence interval, 98.6-100) in distinguishing cases from controls, with positive and negative predictive values of 100% and 95.7%, respectively.

CONCLUSIONS

Our findings indicate that early autonomic tone balance abnormalities are present in newborns with HCA and suggest that early dynamic analysis of pulse oximetry signals could be useful in identifying affected infants.

Transient hypothyroxinemia of prematurity and histological chorioamnionitis

BACKGROUND

Transient hypothyroxinaemia of prematurity (THOP) is a common condition of preterm infants whose causes remain unclear. We tested the hypothesis that THOP is associated with histological chorioamnionitis (HCA).

METHODS

Whole blood T4 and TSH concentrations on day 4 and at 40 weeks' postmenstrual age (rtx-T4 and rtx-TSH), placental histology and illness severity were prospectively evaluated in 155 very low birth weight (VLBW) infants.

RESULTS

HCA-positive infants showed significantly decreased blood total T4 concentrations on day 4, as compared to the HCA-negative population (P<0.0001), along with comparable TSH, rtx-T4, and rtx-TSH blood concentrations. None of the infants showed evidence of hypothyroidism during the study. A total T4 < or = 4.4 microg/dL on postnatal day 4 identified HCA-positive newborns with 90.8%, sensitivity, 94.7%, specificity, 96.7% positive predictive and 85.7% negative predictive values. HCA (OR: 32.19; 95% CI: 8.95-115.64), birth weight < or = 880 g (OR: 4.1; 1.15-14.64), and RDS (OR: 3.71, 95% CI: 1.13-12.25) were independently associated with evidence of hypothyroxinaemia on day 4.

CONCLUSION

Our findings indicate a previously un-recognized relationship between HCA and THOP, hence suggesting a predominant role for a fetal systemic inflammatory response syndrome in the pathogenesis of THOP.

Increasing illness severity in very low birth weight infants over a 9-year period

Background

Recent reports have documented a leveling-off of survival rates in preterm infants through the 1990's. The objective of this study was to determine temporal changes in illness severity in very low birth weight (VLBW) infants in relationship to the outcomes of death and/or severe IVH.

Methods

Cohort study of 1414 VLBW infants cared for in a single level III neonatal intensive care unit in Delaware from 1993–2002. Infants were divided into consecutive 3-year cohorts. Illness severity was measured by two objective methods: the Score for Neonatal Acute Physiology (SNAP), based on data from the 1^st day of life, and total thyroxine (T₄), measured on the 5^th day of life. Death before hospital discharge and severe intraventricular hemorrhage (IVH) were investigated in the study sample in relation to illness severity. The fetal death rate was also investigated. Statistical analyses included both univariate and multivariate analysis.

Results

Illness severity, as measured by SNAP and T_4, increased steadily over the 9-year study period with an associated increase in severe IVH and the combined outcome of death and/or severe IVH. During the final 3 years of the study, the observed increase in illness severity accounted for 86% (95% CI 57–116%) of the variability in the increase in death and/or severe IVH. The fetal death rate dropped from 7.8/1000 (1993–1996) to 5.3/1000 (1999–2002, p = .01) over the course of the study.

Conclusion

These data demonstrate a progressive increase in illness in VLBW infants over time, associated with an increase in death and/or severe IVH. We speculate that the observed decrease in fetal death, and the increase in neonatal illness, mortality and/or severe IVH over time represent a shift of severely compromised patients that now survive the fetal time period and are presented for care in the neonatal unit.