Outcomes of very-low-birth-weight infants exposed to maternal clinical chorioamnionitis: a multicentre study

Short-term variation of the fetal heart rate as a marker of intraamniotic infection in pregnancies with preterm prelabor rupture of membranes: a historical cohort study

INTRODUCTION

Intraamniotic infection (IAI) and subsequent early-onset neonatal sepsis (EONS) are among the main complications associated with preterm prelabor rupture of membranes (PPROM). Currently used diagnostic tools have been shown to have poor diagnostic performance for IAI. This study aimed to investigate whether the exposure to IAI before delivery is associated with short-term variation of the fetal heart rate in pregnancies with PPROM.

METHODS

Observational cohort study of 678 pregnancies with PPROM, delivering between 24 + 0 and 33 + 6 gestational weeks from 2012 to 2019 in five labor units in Stockholm County, Sweden. Electronic medical records were examined to obtain background and exposure data. For the exposure IAI, we used the later diagnosis of EONS in the offspring as a proxy. EONS is strongly associated to IAI and was considered a better proxy for IAI than the histological diagnosis of acute chorioamnionitis, since acute chorioamnionitis can be observed in the absence of both positive microbiology and biochemical markers for inflammation. Cardiotocography traces were analyzed by a computerized algorithm for short-term variation of the fetal heart rate, which was the main outcome measure.

RESULTS

Twenty-seven pregnancies were categorized as having an IAI, based on the proxy diagnosis of EONS after birth. Fetuses exposed to IAI had significantly lower short-term variation values in the last cardiotocography trace before birth than fetuses who were not exposed (5.25 vs 6.62 ms; unadjusted difference: -1.37, p = 0.009). After adjustment for smoking and diabetes, this difference remained significant. IAI with a later positive blood culture in the neonate (n = 12) showed an even larger absolute difference in STV (-1.65; p = 0.034), with a relative decrease of 23.5%.

CONCLUSION

In pregnancies with PPROM, fetuses exposed to IAI with EONS as a proxy have lower short-term variation of the fetal heart rate than fetuses who are not exposed. Short-term variation might be useful as adjunct surveillance in pregnancies with PPROM.

Clinical utility of gastric fluid cytokine levels in preterm infants for predicting histological chorioamnionitis

BACKGROUND

The risk of various complications, such as neonatal death, early onset sepsis, and chronic lung disease, is increased in infants born to mothers with chorioamnionitis (CAM). However, predicting the diagnosis of histological CAM (hCAM) in the early postnatal period is challenging for clinicians due to pathological considerations. Therefore, an early diagnostic tool for hCAM is needed. Gastric fluid at birth is considered a suitable biomarker for predicting the intrauterine environment because most of its components are from amniotic fluid, and the sampling technique is less invasive. This study aimed to evaluate the clinical utility of cytokines in the gastric fluid of preterm infants at birth as predictors of hCAM.

METHODS

We retrieved gastric fluid and serum from 21 preterm infants with a gestational age of ≤ 32 weeks within 1 h after birth and used cytometric bead array to measure the concentrations of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha, and interferon-gamma. We compared the cytokine concentrations in the gastric fluid and serum of the preterm infants born to mothers with or without hCAM.

RESULTS

The gastric fluid, serum IL-6, and serum IL-10 concentrations were significantly higher in the hCAM group than that in the non-hCAM group. The best cutoff values for predicting hCAM was > 2,855 pg/mL and > 315 pg/mL for IL-6 in the gastric fluid and serum, respectively. Receiver operating characteristic curves showed that gastric fluid IL-6 concentrations correlated more strongly with the presence of hCAM than serum IL-6 concentrations.

CONCLUSION

IL-6 in the gastric fluid at birth may be a more promising biomarker for predicting the presence of hCAM than that in serum. IL-6 concentration analysis in the gastric fluid at birth might help to diagnose hCAM immediately after birth and improve the prognosis of preterm infants.

The influence of chorioamnionitis on respiratory drive and spontaneous breathing of premature infants at birth: a narrative review

Most very premature infants breathe at birth but require respiratory support in order to stimulate and support their breathing. A significant proportion of premature infants are affected by chorioamnionitis, defined as an umbrella term for antenatal inflammation of the foetal membranes and umbilical vessels. Chorioamnionitis produces inflammatory mediators that potentially depress the respiratory drive generated in the brainstem. Such respiratory depression could maintain itself by delaying lung aeration, hampering respiratory support at birth and putting infants at risk of hypoxic injury. This inflammatory-mediated respiratory depression may contribute to an association between chorioamnionitis and increased requirement of neonatal resuscitation in premature infants at birth. This narrative review summarises mechanisms on how respiratory drive and spontaneous breathing could be influenced by chorioamnionitis and provides possible interventions to stimulate spontaneous breathing.  Conclusion: Chorioamnionitis could possibly depress respiratory drive and spontaneous breathing in premature infants at birth. Interventions to stimulate spontaneous breathing could therefore be valuable. What is Known: • A large proportion of premature infants are affected by chorioamnionitis, antenatal inflammation of the foetal membranes and umbilical vessels. What is New: • Premature infants affected by chorioamnionitis might be exposed to higher concentrations of respiratory drive inhibitors which could depress breathing at birth. • Premature infants affected by chorioamnionitis seem to be associated with a higher and more extensive requirement of resuscitation at birth.

Improved efficiency in the management of newborns with infectious risk factors by the sepsis risk calculator and clinical observation

OBJECTIVE

To evaluate the efficiency of the sepsis risk calculator and the serial clinical observation in the management of late preterm and term newborns with infectious risk factors.

METHOD

Single-center, observational, two-phase cohort study comparing the rates of neonates born ≥35 weeks' gestation, ≥2000 g birthweight, and without major congenital anomalies, who were screened and/or received antibiotics for early-onset neonatal sepsis risk at our center during two periods, before (January/2018-June/2019) and after (July/2019-December/2020) the implementation of the sepsis risk calculator.

RESULTS

A total of 1796 (Period 1) and 1867 (Period 2) patients with infectious risk factors were included. During the second period, tests to rule out sepsis were reduced by 34.0 % (RR, 95 %CI): 0.66 (0.61, 0.71), blood cultures by 13.1 %: 0.87 (0.77, 0.98), hospital admissions by 13.5 %: 0.86 (0.76, 0.98) and antibiotic administration by 45.9 %: 0.54 (0.47, 0.63). Three cases of early-onset neonatal sepsis occurred in the first period and two in the second. Clinical serial evaluation would have detected all true cases.

CONCLUSIONS

The implementation of a sepsis risk calculator in the management of newborns ≥35 weeks GA, ≥2000 g birthweight, without major congenital anomalies, with infectious risk factors is safe and adequate to reduce laboratory tests, blood cultures, hospital admissions, and antibiotics administration. Serial clinical observation, in addition, could be instrumental to achieve or even improve this goal.

Management and Interventions in Previable and Periviable Preterm Premature Rupture of Membranes: A Review

Importance

Periviable and previable premature rupture of membranes (pPPROM) occurs in <1% of pregnancies but can have devastating consequences for the mother and the fetus. Understanding risk factors, possible interventions, and both maternal and neonatal outcomes will improve the counseling and care provided for these patients.

Objective

The aim of this review is to describe the etiology, risk factors, management strategies, neonatal and maternal outcomes, and recurrence risk for patients experiencing pPPROM.

Evidence Acquisition

A PubMed, Web of Science, and CINAHL search was undertaken with unlimited years searched. The search terms used included "previable" OR "periviable" AND "fetal membranes" OR "premature rupture" OR "PROM" OR "PPROM." The search was limited to English language.

Results

There were 181 articles identified, with 41 being the basis of review. Multiple risk factors for pPPROM have been identified, but their predictive value remains low. Interventions that are typically used once the fetus reaches 23 to 24 weeks of gestation have not been shown to improve outcomes when used in the previable and periviable stage. Neonatal outcomes have improved over time, but survival without severe morbidity remains low. Later gestational age at the time of pPPROM and longer latency period have been shown to be associated with improved outcomes.

Conclusions and Relevance

Periviable and previable premature rupture of membranes are uncommon pregnancy events, but neonatal outcomes remain poor, and routine interventions for PPROM >24 weeks of gestation have not proven beneficial. The 2 most reliable prognostic indicators are gestational age at time of pPPROM and length of the latency period.

Risk factors and neonatal outcomes of pulmonary air leak syndrome in extremely preterm infants: A nationwide descriptive cohort study

Most extremely preterm infants (EPIs), who were born before 28 weeks of gestation, with pulmonary air leak syndrome (ALS) are symptomatic, often severe, and require drainage. EPIs with severe air leak syndrome (sALS) that require tube drainage or needle aspiration are at high risk of morbidities and mortality. This study aimed to investigate perinatal characteristics, morbidities, and mortality in EPIs with sALS, and to estimate the risk of mortality according to gestational age (GA). A prospective cohort study conducted from 2013 to 2020 compiled the Korean Neonatal Network database to evaluate the incidence, perinatal characteristics, and outcomes of sALS in EPIs born before 28 weeks of gestation. Among 5666 EPIs, the incidence of sALS was 9.4% and inversely related to GA. From this cohort, we compared 532 EPIs with sALS to 1064 EPIs without sALS as controls, matching the subjects by GA and birth weight. Preterm premature rupture of membranes, oligohydramnios, resuscitation after birth, low Apgar scores, repeated surfactant administration, persistent pulmonary hypertension of the newborn, and pulmonary hemorrhage were associated with the development of pneumothorax. The sALS group required a higher fraction of inspired oxygen and more invasive respiratory support at both 28 days of life and 36 weeks of postmenstrual age. The sALS group had a higher incidence of bronchopulmonary dysplasia and major brain injury. The mortality rate was higher in the sALS group than in the control group (55.3% vs 32.5%, P < .001), and the ALS group had a 1.7 times risk of mortality than the control group. More attention should be paid to sALS in EPIs because the frequency of sALS increased as GA decreased, and the risk of mortality was more significant at lower GA.

Necrotizing enterocolitis: recent advances in treatment with translational potential

Necrotizing enterocolitis (NEC) is one of the most prevalent and devastating gastrointestinal disorders in neonates. Despite advances in neonatal care, the incidence and mortality due to NEC remain high, highlighting the need to devise novel treatments for this disease. There have been a number of recent advancements in therapeutic approaches for the treatment of NEC; these involve remote ischemic conditioning (RIC), stem cell therapy, breast milk components (human milk oligosaccharides, exosomes, lactoferrin), fecal microbiota transplantation, and immunotherapy. This review summarizes the most recent advances in NEC treatment currently underway as well as their applicability and associated challenges and limitations, with the aim to provide new insight into the paradigm of care for NEC worldwide.

Impact of premature rupture of membranes on clinical outcomes of extremely premature infants: A propensity score matching study

Background

Premature rupture of membranes (PROM) is a common cause of extremely premature infants (EPIs) and also leads to adverse preterm complications. However, the effect of PROM on EPIs remains contradictory. This study used propensity score matching (PSM) to adjust the baseline characteristics to explore the impact of PROM on clinical outcomes of extremely premature infants (EPIs).

Methods

Medical data of 470 EPIs at gestational age < 28weeks who received prenatal examination in our hospital between January 1, 2015 and December 31, 2020 were analyzed retrospectively. According to the presence or absence of PROM, they were divided into a PROM group and a non-PROM group. Ten covariates including birth weight, male sex, artificial conception, cesarean delivery, 5-min Apgar score ≤ 7, oligohydramnios, gestational hypertension, preeclampsia, antenatal steroid use, and complete steroid treatment were matched 1:1 by PSM. The major complication occurrence and mortality during hospitalization were compared between the two groups by t-test, nonparametric test or x 2 test.

Results

Among the 470 infants enrolled, 157 (33.4%) were in the PROM group and 313 in the no-PROM group. After matching the ten confounding factors,276 cases were successfully enrolled. The incidence of early pulmonary hypertension (EPH) and severe retinopathy of prematurity (ROP) in the PROM group were higher than those in the no-PROM group [44.2% (61/138) vs. 29.0% (40/138); 34.8% (48/138) vs. 21.7% (30/138), x ² = 6.886 and 5.790, both P < 0.05]. However, there was no significant difference in the in-hospital mortality and the incidence of other major complications between the two groups (all P > 0.05).

Conclusions

PROM increased the incidence of EPH and severe ROP in EPI, but had no significant impact on in-hospital mortality, length of hospital stay, and the incidence of other complications.

Chorioamnionitis-exposure alters serum cytokine trends in premature neonates

OBJECTIVES

Determine if chronologic age and/or chorioamnionitis exposure alter normal serum cytokine and chemokine levels in uninfected preterm neonates during their initial NICU stay.

STUDY DESIGN

A 7-plex immunoassay measured levels of serum IL-1β, IL-6, IL-8, IL-10, TNF-α, CCL2, and CCL3 longitudinally from chorioamnionitis-exposed and unexposed preterm neonates under 33 weeks' gestation.

RESULTS

Chorioamnionitis-exposed and unexposed preterm neonates demonstrated differences in the trends of IL-1β, IL-6, IL-8, IL-10, TNF-α, and CCL2 over the first month of life. The unexposed neonates demonstrated elevated levels of these inflammatory markers in the first two weeks of life with a decrease by the third week of life, while the chorioamnionitis-exposed neonates demonstrated differences over time without a predictable pattern. Chorioamnionitis-exposed and unexposed neonates demonstrated altered IL-10 and TNF-α trajectories over the first twelve weeks of life.

CONCLUSION

Chorioamnionitis induces a state of immune dysregulation in preterm neonates that persists beyond the immediate neonatal period.

Association of clinical signs of chorioamnionitis with histological chorioamnionitis and neonatal outcomes

BACKGROUND

Chorioamnionitis is a risk factor for fetal and neonatal outcomes. Therefore, predicting histological chorioamnionitis (HCA) and neonatal outcomes using clinical parameters could be helpful in management and preventing morbidities.

OBJECTIVE

To determine if parameters of clinical chorioamnionitis (CCA) would be associated with HCA and neonatal outcomes.

STUDY DESIGN

In this cohort study using a retrospective design, we analyzed the performance of signs of CCA in predicting HCA, and neonatal outcomes. Data were extracted from the electronic health record for all neonates with documented CCA delivered at our institution from 2011 to 2016. We compared our findings based on the old ACOG definition of CCA and the new definition released in 2017 - maternal fever plus any of fetal tachycardia, maternal leukocytosis, and purulent vaginal discharge. Maternal tachycardia and uterine tenderness were removed from the new criteria. Neonatal laboratory samples on admission, 12 h and 24 h were used to define the three time points of neonatal suspected sepsis.

RESULTS

There were 530 mothers-infant dyads with chorioamnionitis. Seventy-three were preterm, and 457 were term. Eighty-eight percent of the preterm mothers had CCA, and HCA was present in 62.5% of 72 preterm placentas. Preterm infants with placental HCA significantly had lower birth weight, gestational age, placental weight, and more infants with lower 5-minute Apgar scores, compared to those with no HCA. In preterm infants, maternal urinary tract infection was significantly associated with decreased odds for HCA (OR 0.22, CI 0.10 - 0.71). More preterm babies with suspected sepsis criteria at the 3 time points had HCA (all p ≤ .01). In the term cohort, 95.4% and 65.6% had CCA and HCA, respectively. In term infants (n = 457), maternal leukocytosis (p = .002) and prolonged rupture of membranes (PROM; p = 002) were associated with HCA. Suspected sepsis was associated with PROM (p = .04), HCA (p = .0001), and maternal leukocytosis (p ≤ .05) in at least 1 of the 3 time points.

CONCLUSION

Though maternal leukocytosis was significantly associated with the presence of HCA in the term cohort, there were no CCA criteria that accurately predicted presence of HCA in either the preterm or the term infants.

Management of neonates with 35 weeks of gestational age or more with infectious risk factors at birth: opportunities for improvement

OBJECTIVES

The Northern California Kaiser-Permanente Neonatal Sepsis Risk Calculator (SRC) has proved to be safe and effective in reducing laboratory tests, hospital admissions, and administration of antibiotics to patients at risk of early-onset neonatal sepsis (EONS). Many studies have focused on maternal chorioamnionitis as the principal risk factor for EONS. We wanted to know if the use of the SRC could be equally efficient in the context of several other infectious risk factors (IRF), in addition to chorioamnionitis, such as intrapartum maternal fever, GBS colonization and/or prolonged rupture of membranes (PROM).

METHODS

Systematic study of neonates with ≥35 weeks gestational age (GA), born in our tertiary university hospital during a period of 18 months. Patients were retrospectively assessed with the SRC and its recommendations were compared with the actual management. A bivariate analysis of perinatal interventions, and outcomes was performed.

RESULTS

A total of 5,885 newborns were born during the study period and 1783 mothers (31%) had at least one IRF. The incidence of culture-proven EONS was 0.5‰. The use of the SRC would have reduced laboratory evaluations (CBC and CRP) from 56.2 to 23.3%, and blood cultures, hospital admissions and antibiotic therapy from 22.9 to 15.5%, 17.8 and 7.6%, respectively. The management based on patients' symptoms would have shown a reduction to 7.5% in all the outcomes of interest.

CONCLUSIONS

Both, the SRC and the management based on clinical findings, are safe and efficient to reduce the number of analytical studies, hospital admissions and administration of antibiotics to neonates with IRF.

Epigenetic regulation of pediatric and neonatal immune responses

Epigenetic regulation of transcription is a collective term that refers to mechanisms known to regulate gene transcription without changing the underlying DNA sequence. These mechanisms include DNA methylation and histone tail modifications which influence chromatin accessibility, and microRNAs that act through post-transcriptional gene silencing. Epigenetics is known to regulate a variety of biological processes, and the role of epigtenetics in immunity and immune-mediated diseases is becoming increasingly recognized. While DNA methylation is the most widely studied, each of these systems play an important role in the development and maintenance of appropriate immune responses. There is clear evidence that epigenetic mechanisms contribute to developmental stage-specific immune responses in a cell-specific manner. There is also mounting evidence that prenatal exposures alter epigenetic profiles and subsequent immune function in exposed offspring. Early life exposures that are associated with poor long-term health outcomes also appear to impact immune specific epigenetic patterning. Finally, each of these epigenetic mechanisms contribute to the pathogenesis of a wide variety of diseases that manifest during childhood. This review will discuss each of these areas in detail. IMPACT: Epigenetics, including DNA methylation, histone tail modifications, and microRNA expression, dictate immune cell phenotypes. Epigenetics influence immune development and subsequent immune health. Prenatal, perinatal, and postnatal exposures alter immune cell epigenetic profiles and subsequent immune function. Numerous pediatric-onset diseases have an epigenetic component. Several successful strategies for childhood diseases target epigenetic mechanisms.

Current therapy option for necrotizing enterocolitis: Practicalities and challenge

Necrotizing enterocolitis (NEC) is one of the most prevalent neonatal gastrointestinal disorders. Despite ongoing breakthroughs in its treatment and prevention, the incidence and mortality associated with NEC remain high. New therapeutic approaches, such as breast milk composition administration, stem cell therapy, immunotherapy, and fecal microbiota transplantation (FMT) have recently evolved the prevention and the treatment of NEC. This study investigated the most recent advances in NEC therapeutic approaches and discussed their applicability to bring new insight to NEC treatment.

Clinical chorioamnionitis and histologic placental inflammation: association with early-neonatal sepsis

OBJECTIVE

Chorioamnionitis and fetal inflammatory response syndrome (FIRS) are significant risk factors for early onset sepsis (EOS). Recently, the use "Intrauterine Inflammation or Infection or both" or triple I has been proposed, classifying cases into an isolated maternal fever, suspected triple I, or confirmed chorioamnionitis. Evidence suggests that the association between suspected chorioamnionitis and confirmed histological chorioamnionitis (HCA) is not consistent, as well as the impact of HCA on the development of EOS.We aimed to evaluate the association between suspected chorioamnionitis and HCA, the impact of HCA on EOS, and the effect of antepartum antibiotic prophylaxis on EOS.

METHODS

We retrospectively reviewed the medical records of all infants admitted to our institution, between 2017 and 2018, with a diagnosis of chorioamnionitis. We recorded the clinical evidence of chorioamnionitis, the histologic report of the placenta, the maternal and neonatal data, the neonatal inflammatory markers including C-reactive protein (CRP), and the incidence of EOS. The impact of antepartum antibiotic prophylaxis on the infants' CRP and EOS was calculated, and the logistic regression model was performed to estimate the association of confirmed HCA with EOS, while controlling for FIRS stage, gestation age, birth weight, maternal fever, foul-smelling amniotic fluid, and prolonged rupture of membranes.

RESULTS

During the study period, a total of 266 infants were identified; 81 (30%) infants had a confirmed HCA (HCA-present cases), and 185 (70%) infants were diagnosed with suspected triple I (HCA-absent cases). Antepartum antibiotics had been commenced in a significantly higher proportion in HCA-present cases (46%) in comparison to 14% of HCA-absent cases (p < .001). HCA-present infants were of significantly lower gestation (31.6 ± 4weeks versus 33.3 ± 4weeks, p = .004), and birth weight (1826 ± 840 g versus 2092 ± 849 g, p = .019), they had a significantly higher rate of clinical symptoms (31% versus 6%, p < .001), and a higher CRP at birth and 24 h (1.4 ± 1.5 mg/dL versus 0.3 ± 0.2 mg/dL, p < .001, and 2.1 ± 2.3 mg/dL versus 0.4 ± 0.6 mg/dL, p < .001, respectively). All HCA-present cases had evidence of FIRS; 43% were stage I, 25% stage II, and 32% were FIRS stage III. A significantly higher proportion of HCA-present infants were diagnosed with EOS (46% as compared to 6%, p < .001). The antepartum antibiotic administration was related to a significantly lower CRP at birth and 24 h only in HCA-present cases, albeit not with any reduction ιn EOS incidence. HCA was significantly associated with EOS (RR 3.18, 95% CI 2.81-5.18, p < .001). After adjusting for perinatal factors, the presence of HCA (OR 7.89, 95% CI 1.19-23.34, p = .032) and an advanced FIRS stage (OR 10.35, 95% CI 4.23-25.32, p < .001) were significantly associated with EOS.

CONCLUSIONS

Amongst infants with suspected chorioamnionitis, the diagnosis is partially supported by histological confirmation, and that is more prominent in pregnancies of a lower gestation. The presence of HCA and an advanced FIRS stage predispose to an increased risk of EOS after adjusting for other perinatal and neonatal factors. The antepartum prophylaxis against intra-amniotic infection was related to a significantly lower CRP in HCA-present cases.

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

OBJECTIVE

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

DATA SOURCES

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

METHODS OF STUDY SELECTION

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

TABULATION, INTEGRATION, AND RESULTS

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

CONCLUSION

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

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020156812.

Bacterial endotoxin-induced maternal inflammation leads to fetal intestinal injury and affects microbial colonization in the neonatal period

BACKGROUND

Intraamniotic infection is associated with an increased risk of multiple adverse outcomes in offspring, especially neonatal necrotizing enterocolitis (NEC), which is one of the serious gastrointestinal diseases in neonates. However, the underlying mechanism remains undefined. We hypothesize that bacterial endotoxin-induced maternal inflammation causes intestinal injury in offspring, thereby affecting the composition of the intestinal microbiome.

METHODS

Pregnant Sprague Dawley rats were received intraperitoneal injections with 700 μg/kg lipopolysaccharide (LPS, which was the same as bacterial endotoxin) or saline at 15 days of gestation. Pups were allowed to deliver naturally and euthanized at days 0, 3 and 7 after birth. Intestinal tissue and feces samples from offspring were collected to evaluate the effects of maternal inflammation on intestinal flora colonization and intestinal mucosal development.

RESULTS

Significant intestinal injury of the offspring induced by prenatal LPS exposure was observed on day 0 and 3 after birth. In addition, prenatal LPS exposure also induced significant changes in the intestinal microbiome of the offspring with a significant increase in Proteobacteria (Escherichia-Shigella) and a decrease in Firmicutes at 7 days after birth.

CONCLUSIONS

Thus, our findings suggest that LPS-induced maternal inflammation induces intestinal injury in offspring and subsequently leads to NEC-like changes in the composition of the intestinal microbiome.

Factors associated with extubation failure in very low birth weight infants: a cohort study in the northeast Brazil

OBJECTIVES

Identifying and understanding the main risk factors associated with extubation failure of very low birthweight (VLBW) infants in different populations can subsequently help in establishing better criteria while taking decision of extubation. The aim of the study was to identify factors associated with extubation failure in VLBW infants.

METHODS

A cohort study of VLBW infants who underwent their first extubation between April 2018 and December 2019 in a Neonatal Intensive Care Unit, Alagoas, Brazil, were included in this study. Extubation failure was defined as reintubation within seven days of extubation. Relative risks of predictive variables different between the extubation success group (ES) and extubation failure group (EF) were estimated with a robust Poisson regression model.

RESULTS

Out of the 112 infants included, 26 (23%) cases exhibited extubation failure. Extremely low birth weight (RR 2.55, 95% CI 1.07, 6.06), mechanical ventilation duration for first extubation greater than seven days (RR 2.66, 95% CI 1.10, 6.45), vaginal delivery (RR 2.07, 95% CI 1.03, 4.18) and maternal chorioamnionitis (RR 4.89, 95% CI 1.26-18.98) remained independently associated with extubation failure. EF had a significant greater need for respiratory support, longer oxygen therapy duration, more bronchopulmonary dysplasia (BPD) and longer length of hospital stay, even when adjusted for confounding variables.

CONCLUSIONS

Extremely low birth weight infants needing mechanical ventilation, wherein the duration for first extubation was longer than seven days, with vaginal delivery and maternal chorioamnionitis failed more frequently at the first attempt of extubation. And this failure increased the risk of BPD and the length of hospital stay.

Contribution of vaginal culture to predict early onset neonatal infection in preterm prelabor rupture of membranes

BACKGROUND

Preterm prelabor rupture of membranes (PPROM) is a major cause of morbidity and mortality for both the mother and the newborn. The vaginal germ profile in PPROM is poorly known, particularly regarding the risk of early-onset neonatal infection (EONI).

OBJECTIVE

To determine microbiological risk factors for EONI in case of PPROM before 34 weeks of gestation (WG).

STUDY DESIGN

A retrospective single-center cohort of patients with PPROM before 34 W G from 2008 to 2016. Vaginal swabs were obtained at admission and at delivery as per usual care and were analyzed by Gram stain and culture for vaginal dysbiosisi.e lactobacilli depletion and/or presence of potential pathogens.

RESULTS

Among 268 cases of PPROM, 39 neonates had EONI 14.55 %; (95 %CI 0.11 - 0.19) Overall, vaginal samples culture was positive in 16.67 % (95 %CI 11.95 %-22.32 %) at the time of rupture and 24.76 % (95 %CI 19.02 %-31.23 %) at delivery, with no significant differences between EONI and no-EONI groups (p = 0.797 and 0.486, respectively), including for Group B Streptococci (GBS) and Escherichia coli. EONI was significantly associated with dysbiosis at the time of rupture (23.94 % versus 10.35 % in the absence of dysbiosis, p = 0.009) and at delivery (19.70 % versus 3.90 % if no dysbiosis, p < 0.001). Clinical intra-uterine infection was present in 78.5 % (n = 31) of the EONI group versus 37.2 % (n = 85) in the non-EONI group (p < 0.001) and chorioamnionitis and/or funisitis were found in 97.3 % and 91.9 %, respectively in the EONI group, versus 56.11 % and 53.96 %, respectively, in the non-EONI group (p < 0.001).

CONCLUSION

Dysbiosis following rupture and at delivery, but not the presence of pathogens in the VS culture, was associated with the risk of EONI in case of PPROM.

Association of chorioamnionitis and patent ductus arteriosus in a national U.S. cohort

OBJECTIVE

To estimate the effect of clinical chorioamnionitis on the risk of patent ductus arteriosus (PDA).

STUDY DESIGN

A secondary analysis of all deliveries >23 gestational weeks from the U.S. Consortium on Safe Labor (CSL) study. The primary exposure was a clinical diagnosis of chorioamnionitis, and the outcome was a diagnosis of PDA. Generalized estimating equations with estimated error variance for women with multiple deliveries were utilized. Models adjusted for age, race, region, delivery year, body mass index, infant sex, multiple gestation, mode of delivery, and antenatal corticosteroid exposure.

RESULTS

Among 228,438 deliveries, a diagnosis of PDA was more frequent with chorioamnionitis exposure versus without (9.2% vs. 3.0%; OR: 3.25; 95% CI: 2.92-3.62). Chorioamnionitis was associated with higher adjusted odds of PDA (AOR: 2.18; 95% CI: 1.93-2.45). In sensitivity analyses, the association between chorioamnionitis and PDA held after adjustment for gestational age at delivery (AOR: 1.28; 95% CI: 1.13-1.44).

CONCLUSIONS

Chorioamnionitis was associated with increased odds of PDA. Robust exposure and outcome ascertainment with careful assessment of confounding is needed to further investigate this epidemiologic association.

Radiological screening of maternal periodontitis for predicting adverse pregnancy and neonatal outcomes

It is well known that periodontitis, diagnosed mainly by periodontal probing, is associated with adverse pregnancy outcomes. However, periodontal probing is time-consuming, highly discomforting, inaccurate, and invasive. We aimed to assess whether periodontitis severity based on radiological staging in accordance with the 2017 new consensus classification was related to adverse pregnancy and neonatal outcomes. The medical records of 165 mothers who underwent panoramic radiography within 5 years before and after the time of delivery and of their singleton neonates were retrospectively reviewed. Twenty-two mothers (13.3%) had severe periodontitis (SP), and 143 (86.7%) had mild or moderate periodontitis (MP). In relation to adverse pregnancy outcomes, uterine leiomyoma (18.2% vs. 4.2%, P = 0.029), chronic hypertension (9.1% vs. 0.7%, P = 0.047), and preeclampsia (13.6% vs. 2.1%, P = 0.032) occurred significantly more frequently in the SP group than in the MP group. The incidences of very preterm birth (13.6% vs. 1.4%, P = 0.017), extremely preterm birth (9.1% vs. 0.7%, P = 0.047), and small for gestational age (22.7% vs. 5.6%, P = 0.017) were also significantly higher in the SP group than in the MP group. Radiological screening of maternal periodontitis could be useful for predicting adverse pregnancy and neonatal outcomes as well as diagnosing SP in pregnant women.

Prenatal low-dose endotoxin exposure prolongs intestinal epithelial activation after birth and contributes to necrotizing enterocolitis

PURPOSE

To investigate the effects of low dose endotoxin on transcriptional activity in intestinal epithelium, and its role in necrotizing enterocolitis (NEC).

METHODS

Lipopolysaccharides (LPS) were injected into the amniotic cavity of pregnant mice under ultrasound guidance. The effects of LPS on fetal and neonatal intestines were determined. Mouse pups were exposed to low dose LPS (0.01 μg per fetus) prenatally and subjected to experimental NEC after birth. The incidence and severity of NEC, as well as intestinal permeability, NF-κB activation, and IL-6 expression were studied. The signaling pathways in the intestinal epithelial cells (IECs) that were activated by LPS were also investigated.

RESULTS

Low dose LPS did not increase apoptosis, myeloperoxidase activity, histological injury or NF-κB activity in fetal intestines. However, prenatal low dose LPS exposure disturbed the transient and self-limited activation of NF-κB in neonatal intestines after birth. Importantly, it increased the incidence and severity of experimental NEC in neonatal mice. In primary IECs, low dose LPS induced IRAK-1 expression via activation of GSK3β. Elevated IRAK-1 levels prolonged the activation of IECs upon stimulation by high dose LPS.

CONCLUSION

Prenatal low dose endotoxin exposure disturbs self-limited postnatal epithelial cell activation and predisposes the neonatal intestine to NEC.

LEVEL OF EVIDENCE

Not applicable (experimental animal study).

Transabdominal amniocentesis in expectant management of preterm premature rupture of membranes: A single center prospective study

AIMS

The aim of this study was to evaluate the role of IL-6 point-of-care test in amniotic fluid obtained from serial amniocentesis in expectantly managed women with PPROM between 24 and 34 weeks of gestation.

METHODS

We conducted a prospective observational cohort study which included 62 pregnant women with PPROM in gestational weeks between 22+0 and 34+0. Women aged >18 years were eligible if they presented with PPROM and a singleton pregnancy. Only women who delivered at >24.0 weeks were included in the study. In all women, the maternal blood sampling and a transabdominal amniocentesis were performed at the time of admission prior to the administration of corticosteroids, antibiotics, or tocolytics, to rule out signs of chorioamnionitis. Maternal temperature, maternal serum C-reactive protein (CRP) and white blood cell (WBC) counts were assayed every subsequent day until delivery. Amniotic fluid was used for the clinical assessment (IL-6 point-of-care test, identification of microorganisms in the amniotic fluid. After one week of expectant management of PPROM, second amniocentesis with amniotic fluid sampling was performed in patients who did not deliver. For all newborns, medical records regarding neonatal morbidity and mortality were reviewed.

RESULTS

In total, 62 women aged 19 to 41 years were recruited in the study. The mean gestational age at the time of PPROM was 31+0, the mean gestational age at labor was 32+1, and the median time from PPROM to childbirth was 112 h. IL-6 point-of-care test values above 1,000 pg/mL (positive Il-6 AMC) were found in 12 women (19.4%) with median interval from PPROM to childbirth 56 h (min-max: 6.4-288). IL-6 point-of-care test values below 1,000 pg/mL (negative Il-6 AMC) were found in 51 women (81.0%). The neonatal mortality rate was 1.9% and was associated with prematurity.

CONCLUSION

The major clinical finding of our study is that serial transabdominal amniocentesis with Il-6 point-of-care test helps to identify a high inflammatory status in amniotic fluid in women with PPROM. Subsequent expectant management of women with PPROM does not lead to worsening of short-term neonatal outcomes.

Suspected Neonatal Sepsis: Tenth Clinical Consensus of the Ibero-American Society of Neonatology (SIBEN)

Suspected neonatal sepsis is one of the most common diagnoses made in newborns (NBs), but very few NBs actually have sepsis. There is no international consensus to clearly define suspected neonatal sepsis, but each time that this suspected diagnosis is assumed, blood samples are taken, venous accesses are used to administer antibiotics, and the mother-child pair is separated, with prolonged hospital stays. X-rays, urine samples, and a lumbar puncture are sometimes taken. This is of concern, as generally <10% and no more than 25%-30% of the NBs in whom sepsis is suspected have proven neonatal sepsis. It seems easy to start antibiotics with suspicion of sepsis, but stopping them is difficult, although there is little or no support to maintain them. Unfortunately, the abuse of antibiotics in inpatient and outpatient NBs is foolish. Its negative impact on neonatal health and the economy is a public health problem of epidemiological and even epidemic proportions. This manuscript is a shortened version of the 10^th Clinical Consensus of the Ibero-American Society of Neonatology (SIBEN) on suspected neonatal sepsis at the end of 2018, updated with publications from its completion to February 2020. This manuscript describes useful strategies for everyday neonatal practice when neonatal sepsis is suspected, along with important aspects about the indisputable value of clinical evaluation of the NB and about obtaining and interpreting blood cultures, urine cultures, and other cultures. Likewise, the low value of laboratory tests in suspected neonatal sepsis is demonstrated with evidence and clinical recommendations are made on the appropriate use of antibiotics.

Perinatal risk factors of symptomatic preterm patent ductus arteriosus and secondary ligation

BACKGROUND

There has been conflicting evidence for the association between antenatal factors and the development of symptomatic patent ductus arteriosus (PDA) or failure of pharmacologic treatment, especially for maternal pregnancy-induced hypertension (PIH) or chorioamnionitis. We assessed the perinatal risk factors of symptomatic PDA in preterm infants and those of secondary ligation in infants with pharmacologic treatment for symptomatic PDA using a national cohort.

METHODS

A total of 2961 infants with 22-29 weeks of gestation with symptomatic PDA or no PDA were included from the Korean Neonatal Network database. To identify significant perinatal risk factors associated with symptomatic PDA or secondary ligation, all perinatal factors were included in the univariate and multivariate generalized estimating equation analysis and final model was selected using backward elimination method based on Quasi-likelihood Information Criterion.

RESULTS

Lower gestational age (GA), female gender, maternal PIH and surfactant use were significant risk factors of symptomatic PDA. Antenatal corticosteroid use decreased the risk of symptomatic PDA. For secondary ligation, lower GA and cesarean section were significant risk factors. Adjusted odds ratio (aOR) of PIH as a risk factor of symptomatic PDA was 1.56 [95% confidence interval 1.17-2.08]. In the subgroup analysis according to the GA, lower GA, female gender, multiple pregnancy, maternal PIH and surfactant use increased the risk of symptomatic PDA, and histologic chorioamnionitis and antenatal corticosteroid use decreased the risk of symptomatic PDA only in GA 26-29 weeks group.

CONCLUSION

Lower GA increased the risk of symptomatic PDA and secondary ligation. Maternal PIH and surfactant use increased the risk of symptomatic PDA; however, antenatal corticosteroid use decreased it. Close observation of the clinical symptoms of PDA is needed in preterm infants with maternal PIH.

H. Smith L, Puttonen H, Fyhr IM, Sävman K, Nilsson AK, Klevebro S. Docosahexaenoic Acid and Arachidonic Acid Levels Are Associated with Early Systemic Inflammation in Extremely Preterm Infants

Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2–0.9, P = 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient −0.40; P = 0.010) and AA (correlation coefficient −0.54; p < 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.

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.

Neonatal outcome comparisons between preterm infants with or without early pulmonary hypertension following prolonged preterm premature rupture of membranes before 25 gestational weeks in Korean Neonatal Network

Objective: To determine the outcomes of very low birth weight infants (VLBWIs) following maternal mid-trimester prolonged preterm premature rupture of membranes (PPROM) and subsequent early pulmonary hypertension (PH).Design: Prospective cohort study.Setting: A nationwide web-based registry of VLBWIs from 67 neonatal intensive care units.Patients: VLBWIs registered on the Korean Neonatal Network and born between 23 and 34 gestational weeks.Methods: VLBWIs exposed to maternal PPROM prior to 25 gestational weeks and lasting ≥7 days (PPROM25, n = 402) were matched 1:1 with infants not exposed or exposed within 24 h to PPROM (CON, n = 402), using propensity score matching. The PPROM25 group was subdivided into PPROM25 groups with or without early PH, defined as exposure to inhaled nitric oxide or other pulmonary vasodilators to treat PH within 3 days of life. Clinical variables and major outcomes were compared, and risk factors for mortality and morbidities were analyzed.Results: Of 1790 infants with maternal PPROM, the PPROM25 group comprised 402 (22.5%) infants. Survival rates were similar between the CON and PPROM25 groups (71.6% vs 74.4%); however, the incidence of bronchopulmonary dysplasia (BPD) differed (47.8% and 60.2%, p < .05). Infants in the PPROM25 group with early PH had higher mortality (55.6%) and more severe intraventricular hemorrhage (IVH) (31.7%) than infants in the PPROM25 group without early PH (21.9% and 14.3%, respectively; p < .05). In multivariate analysis, lower 5 min Apgar score and the presence of oligohydramnios increased the risk of development of early PH. The presence of PPROM25 was founded to be a significant risk factor for BPD and early PH in relation to mortality and severe IVH, respectively.Conclusions: In VLBWIs, prolonged exposure to maternal mid-trimester PPROM increased the risk of BPD. Subsequent early PH immediately after birth increased mortality and severe IVH, thus, requires special attention.

Selection criteria for resuscitation and survivability rates for neonates at the limit of viability

AIM

To evaluate outcomes of a cohort of infants born at 23 weeks' gestational age after introducing a new selection score for resuscitation in the delivery room (DR).

METHODS

This was a retrospective charts review study using data from the maternal and newborn registry funded by the Qatar National Research Fund. Parents were consulted prenatally and their wishes were honored. The plan of resuscitation was based on the new selection score. The seven components of the score were four antenatal and three immediate postnatal in the DR. Each component received a score of zero, one, or two according to its presence, uncertainty or absence, respectively. Only a score of≥7 would receive active resuscitation unless specified otherwise during prenatal consultation.

RESULTS

The study reviewed 60 infants that were delivered over a two year period. The DR death rate was 23 of 60 (38%). Thirty-seven infants (61%) were admitted to the NICU. The score was applied only on 37 infants where all score criteria were reported in their files. Twenty infants had score <7; of them 13 (65%) died in the DR and 7 were admitted to NICU of whom two (29%) survived to discharge. Seventeen babies with scores≥7 admitted to NICU of whom nine (51%) survived to discharge. The survival rate to discharge was 13 of 37(35%). A satisfaction survey included 33 neonatal physicians; 32 neonatologists stated the score was easy to comprehend, 26 voted for easy to implement, and 30 voted for ethical relief and moral comfort.

CONCLUSIONS

Using a resuscitation score of seven was associated with improved survival until the discharge of those infants resuscitated. NICU physicians described the score as functional and convenient.

Related Factors of Patent Ductus Arteriosus in Preterm Infants: A Systematic Review and Meta-Analysis

Background: Patent ductus arteriosus (PDA) is a dramatically harmful disease in the neonatal period, in particular common in preterm infants, and our study was to determine related factors of PDA in preterm infants. Methods: A comprehensive literature review was conducted in PubMed, EMBASE, and Web of Science. The pooled odds ratio and standard mean difference were calculated to compare dichotomous and continuous variables, respectively. In addition, we also assessed the heterogeneity and publication bias and carried out sensitivity analysis for each related factor. Results: We included 45 studies with 87,419 individuals. After the primary analysis and a series of adjustments, results showed chorioamnionitis, lower gestational age, lower birth weight, bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, respiratory distress syndrome, sepsis, surfactant treatment, ventilation, and lower platelet count had a positive correlation with PDA, while small for gestational age decreased the incidence of PDA in preterm infants. Besides, premature rupture of membranes, preeclampsia, antenatal steroids, male gender, mean platelet volume, and platelet distribution width were found to have no statistically significant relationship with PDA. Conclusion: Preterm infants with more immature characteristics generally have a higher likelihood to develop PDA. The prevention, diagnosis, and management of PDA may depend on these results, and effective measures can be taken accordingly.

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.

Histological chorioamnionitis, antenatal steroids, and neonatal outcomes in very low birth weight infants: A nationwide study

Background

The aim of this study was to investigate whether some associations between histological chorioamnionitis (HCA) and favorable neonatal outcomes might be linked to those of antenatal steroids (AS) by determining the separate as well as the combined associations of HCA and AS with neonatal outcomes in very low birth weight infants (VLBWIs).

Methods

This was a population-based study of VLBWIs born at 20–33 weeks’ gestation between January 2013 and December 2015 from the Korean Neonatal Network. A total of 4652 VLBWIs were enrolled for prevalence study. Of these, 2900 singleton VLBWIs were used for outcome analyses to evaluate individual associations of HCA and AS simultaneously with correction for potential perinatal factors and an interaction term of HCA and AS.

Results

The overall prevalence of HCA was 34.9% (1623 VLBWIs). Multivariable logistic regression demonstrated that HCA was associated with decreased mortality (adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.29–0.91; P = 0.022), AS were associated with reduction in mortality (aOR, 0.59; 95% CI, 0.39–0.90; P = 0.014) and neonatal seizure (aOR, 0.57; 95% CI, 0.37–0.86; P = 0.008), and a combination of HCA and AS was associated with remarkably lowered severe intraventricular hemorrhage by interacting with each other (aOR, 0.47; 95% CI, 0.25–0.88; P = 0.019).

Conclusions

We suggest that in VLBWIs HCA and AS may be favorable independent factors for neonatal outcome and may also work in synergy for neuroprotection.

Fetal exposure to maternal inflammation interrupts murine intestinal development and increases susceptibility to neonatal intestinal injury

Fetal exposure to chorioamnionitis can impact the outcomes of the developing fetus both at the time of birth and in the subsequent neonatal period. Infants exposed to chorioamnionitis have a higher incidence of gastrointestinal (GI) pathology, including necrotizing enterocolitis (NEC); however, the mechanism remains undefined. To simulate the fetal exposure to maternal inflammation (FEMI) induced by chorioamnionitis, pregnant mice (C57BL/6J, IL-6 ^-/-, RAG ^-/- or TNFR1 ^-/-) were injected intraperitoneally on embryonic day (E)15.5 with lipopolysaccharide (LPS; 100 µg/kg body weight). Pups were delivered at term, and reared to postnatal day (P)0, P7, P14, P28 or P56. Serum and intestinal tissue samples were collected to quantify growth, inflammatory markers, histological intestinal injury, and goblet and Paneth cells. To determine whether FEMI increased subsequent susceptibility to intestinal injury, a secondary dose of LPS (100 µg/kg body weight) was given on P5, prior to tissue harvesting on P7. FEMI had no effect on growth of the offspring or their small intestine. FEMI significantly decreased both goblet and Paneth cell numbers while simultaneously increasing serum levels of IL-1β, IL-10, KC/GRO (CXCL1 and CXCL2), TNF and IL-6. These alterations were IL-6 dependent and, importantly, increased susceptibility to LPS-induced intestinal injury later in life. Our data show that FEMI impairs normal intestinal development by decreasing components of innate immunity and simultaneously increasing markers of inflammation. These changes increase susceptibility to intestinal injury later in life and provide novel mechanistic data to potentially explain why preterm infants exposed to chorioamnionitis prior to birth have a higher incidence of NEC and other GI disorders.

Impact of histological chorioamnionitis on postnatal growth in very-low birth weight infants

BACKGROUND

Postnatal growth restriction remains one of the most common problems of very preterm infants (VPI). Chorioamnionitis is a frequent cause of prematurity. Both have been related to worse postnatal outcomes.

OBJECTIVES

To evaluate the influence of histological chorioamnionitis (CA) on postnatal growth in very premature infants.

METHODS

Retrospective one-to-one matched cohort study assessing growth in infants born at or below 32.0 weeks gestation from mothers for whom histological examination of the placenta was available. Newborns with histological CA were matched and compared with those without it. Postnatal growth was recorded at admission, 14 days of life, 28 days of life and 36 weeks postmenstrual age (PMA). Nutritional support and clinical outcomes were used as covariables.

RESULTS

Eighty-eight patients were included: 44 with fetal or/and maternal placental inflammation, and 44 without histological CA (41% with vasculopathy findings and 59% without). Baseline characteristics were similar between the groups. Change in weight z-scores at 14 days of life, 28 days of life, 36 weeks PMA or at discharge were similar in both groups, with a steady fall and no signs of catch-up. No differences were found in enteral and parenteral nutritional intakes between groups.

CONCLUSIONS

Histological CA did not affect postnatal growth of very preterm infants after matching for birth weight z-scores with non-CA newborns.

Prenatal inflammation impairs intestinal microvascular development through a TNF-dependent mechanism and predisposes newborn mice to necrotizing enterocolitis

Prenatal inflammation is a risk factor for necrotizing enterocolitis (NEC), and it increases intestinal injury in a rat NEC model. We previously showed that maldevelopment of the intestinal microvasculature and lack of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) signaling play a role in experimental NEC. However, whether prenatal inflammation affects the intestinal microvasculature remains unknown. In this study, mouse dams were injected intraperitoneally with lipopolysaccharide (LPS) or saline at embryonic day 17. Neonatal intestinal microvasculature density, endothelial cell proliferation, and intestinal VEGF-A and VEGFR2 proteins were assessed in vivo. Maternal and fetal serum TNF concentrations were measured by ELISA. The impact of TNF on the neonatal intestinal microvasculature was examined in vitro and in vivo, and we determined whether prenatal LPS injection exacerbates experimental NEC via TNF. Here we found that prenatal LPS injection significantly decreased intestinal microvascular density, endothelial cell proliferation, and VEGF and VEGFR2 protein expression in neonatal mice. Prenatal LPS injection increased maternal and fetal serum levels of TNF. TNF decreased VEGFR2 protein in vitro in neonatal endothelial cells. Postnatal TNF administration in vivo decreased intestinal microvasculature density, endothelial cell proliferation, and VEGF and VEGFR2 protein expression and increased the incidence of severe NEC. These effects were ameliorated by stabilizing hypoxia-inducible factor-1α, the master regulator of VEGF. Furthermore, prenatal LPS injection significantly increased the incidence of severe NEC in our model, and the effect was dependent on endogenous TNF. Our study suggests that prenatal inflammation increases the susceptibility to NEC, downregulates intestinal VEGFR2 signaling, and affects perinatal intestinal microvascular development via a TNF mechanism. NEW & NOTEWORTHY This report provides new evidence that maternal inflammation decreases neonatal intestinal VEGF receptor 2 signaling and endothelial cell proliferation, impairs intestinal microvascular development, and predisposes neonatal mouse pups to necrotizing enterocolitis (NEC) through inflammatory cytokines such as TNF. Our data suggest that alteration of intestinal microvascular development may be a key mechanism by which premature infants exposed to prenatal inflammation are at risk for NEC and preserving the VEGF/VEGF receptor 2 signaling pathway may help prevent NEC development.

Association of chorioamnionitis and its duration with neonatal morbidity and mortality

OBJECTIVE

To investigate the association of chorioamnionitis, and secondarily its duration, on neonatal adverse outcomes for infants born <34 weeks vs. ≥34 weeks.

STUDY DESIGN

A secondary analysis from the observational U.S. Consortium on Safe Labor Study. The exposure was chorioamnionitis, and secondarily, its estimated duration. The composite outcome included pneumonia, seizure, necrotizing enterocolitis, sepsis, periventricular/intraventricular/cerebral hemorrhage, mechanical ventilation, and neonatal death. Multivariable logistic regression with generalized estimating equations was used, stratified by gestational age at delivery.

RESULTS

Among 221,274 deliveries, the odds of the neonatal adverse outcome <34 weeks was 2-fold higher among infants exposed to chorioamnionitis vs. those who were not (62.0 vs. 47.7%; AOR: 1.86; 95%CI: 1.25-2.75), and was ~3.5-fold higher ≥34 weeks (9.2 vs. 2.5%; AOR: 3.34; 95% CI: 2.35-4.76). The estimated duration of chorioamnionitis did not change the above associations.

CONCLUSIONS

Chorioamnionitis was associated with an approximately 2- and 3.5-fold increased odds of neonatal adverse outcomes <34 and ≥34 weeks, respectively, regardless of its estimated duration.

Intercenter variability and factors associated with survival without bronchopulmonary dysplasia in extremely preterm newborns

Background: Variability in clinical practice may influence morbidity and mortality in extremely preterm infants. We aimed to know if there are differences in survival and survival without bronchopulmonary dysplasia (BPD) in extremely preterm infants in Spanish tertiary hospitals and the potential associated factors.Methods: Fifteen hospitals from the SEN1500 network were studied. The overall rate of survival without BPD was 61.4%. Hospitals with extreme results were grouped for comparison (Group 1; N = 2480 versus Group 2; N = 2367). A bivariate analysis of the characteristics of patients and perinatal interventions was carried out and the probability of survival without BPD was studied by Cox regression.Results: Survival (79.0 versus 72.9%; p < .001) and survival without BPD (72.5 versus 49.1%; p < .001) were greater in Group 1. Higher gestational age, birth weight, and female sex were associated with better outcomes. Oxygen administration (aHR: 0.868 [95%CI: 0.782, 0.964]; p=.008) and intubation (aHR: 0.767 [95%CI: 0.701, 0.839]; p < .001) in delivery room were associated with lower survival without BPD. The occurrence of patent ductus arteriosus (PDA), sepsis and/or necrotizing enterocolitis (NEC) was independently associated with worse outcomes. After adjusting for confounders, the probabilities of survival without BPD were significantly higher among patients in Group 1: aHR: 1.557 [95% CI: 1.458, 1.662]; p < .001.Conclusions: Among the studied hospitals, we found great variability in clinical practice and in the rates of survival and survival without BPD. A more conservative approach to the use of oxygen and respiratory support seems to be related to an increase in survival without BPD. Complications such as PDA, sepsis, and/or NEC decrease survival without BPD. Other variables not included in the present study could be relevant and deserve further study.

Chorioamnionitis exposure remodels the unique histone modification landscape of neonatal monocytes and alters the expression of immune pathway genes

Chorioamnionitis is an intrauterine infection involving inflammation of the chorion, amnion, and placenta. It leads to a fetal systemic inflammatory response that can alter the transcription of neonatal immune genes. We have previously shown that neonatal monocytes gain the activating histone tail modification H3K4me3 at promoter sites of immunologically important genes as development progresses from preterm neonate to adult. In this study, we applied ChIP-seq and RNA-seq to evaluate the impact of chorioamnionitis on the neonatal monocyte H3K4me3 histone modification landscape over the course of fetal and neonatal immune system development. Chorioamnionitis exposure in neonatal monocytes resulted in a net increase in total monocyte H3K4me3, primarily in introns and intergenic regions. Immune gene expression was decreased in chorioamnionitis-exposed monocytes, with the majority of enriched transcripts falling into pathways that are not linked to the immune system. Over half of all neonatal monocyte H3K4me3 peaks, independent of their location, were associated with active gene transcription. Overall, chorioamnionitis exposure resulted in the global remodeling of the neonatal monocyte H3K4me3 landscape and changes in the expression of known immune genes. These changes resulted in a less robust inflammatory response upon exposure to a secondary challenge, which may explain why chorioamnionitis-exposed neonates have an increased risk of sepsis. DATABASE: ChIP-seq data for U30/O30/Term: GEO GSE81957 ChIP-seq data for U30C/O30C/TermC: GEO GSE111873 RNA-seq data for U/L/CU/CL: GEO GSE111927.

[Diagnosis and management of intra-uterine infection: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVE

To determine the diagnosis criteria and management of intra-uterine inflammation or infection (Triple I, III).

METHODS

PubMed and Cochrane Central databases search.

RESULTS

III is defined as an infection of the fetal membranes, and/or other components like the decidua, fetus, amniotic fluid or placenta. This word should be preferred to the word chorioamnionitis that is less precise (Professional consensus). III clinical signs exhibit poor limited sensibility and specificity (EL3). The diagnosis of III is retained in case of maternal fever (defined by a body temperature≥38°C) with no alternative cause identified and at least 2 signs among the following: fetal tachycardia>160 bpm for 10min or longer, uterine pain of labor, purulent fluid from the cervical canal (Professional consensus). Maternal hyperleukocytosis>20 giga/L in the absence of corticosteroids treatment or increased plasmatic C-reactive protein also argue for III, despite their limited sensibility and specificity (EL3). III requires prompt delivery (Grade A). III is not by itself an indication for cesarean delivery (Professional consensus). Antibiotic treatment should cover Streptococcus agalactiae and Escherichia coli. Antibiotics should be started immediately and maintained all over delivery, to reduce neonatal and maternal morbidity (Grade B). Treatment should rely on a combination of betalactamin and aminoglycoside (Grade B). After vaginal delivery, one single dose of antibiotic is required. Antibiotic duration should be longer in case of bacteremia. Longer duration could be considered in case of persistent fever or of cesarean delivery (Professional consensus).

Chorioamnionitis as a risk factor for retinopathy of prematurity: An updated systematic review and meta-analysis

The role of chorioamnionitis (CA) in the development of retinopathy of prematurity (ROP) is difficult to establish, because CA-exposed and CA-unexposed infants frequently present different baseline characteristics. We performed an updated systematic review and meta-analysis of studies reporting on the association between CA and ROP. We searched PubMed and EMBASE for relevant articles. Studies were included if they examined preterm or very low birth weight (VLBW, <1500g) infants and reported primary data that could be used to measure the association between exposure to CA and the presence of ROP. Of 748 potentially relevant studies, 50 studies met the inclusion criteria (38,986 infants, 9,258 CA cases). Meta-analysis showed a significant positive association between CA and any stage ROP (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.11 to 1.74). CA was also associated with severe (stage ≥3) ROP (OR 1.63, 95% CI 1.41 to 1.89). Exposure to funisitis was associated with a higher risk of ROP than exposure to CA in the absence of funisitis. Additional meta-analyses showed that infants exposed to CA had lower gestational age (GA) and lower birth weight (BW). Meta-regression showed that lower GA and BW in the CA-exposed group was significantly associated with a higher risk of ROP. Meta-analyses of studies with data adjusted for confounders could not find a significant association between CA and ROP. In conclusion, our study confirms that CA is a risk factor for developing ROP. However, part of the effects of CA on the pathogenesis of ROP may be mediated by the role of CA as an etiological factor for very preterm birth.

Prenatal Intra-Amniotic Endotoxin Induces Fetal Gut and Lung Immune Responses and Postnatal Systemic Inflammation in Preterm Pigs

Prenatal inflammation is a major risk for preterm birth and neonatal morbidity, but its effects on postnatal immunity and organ functions remain unclear. Using preterm pigs as a model for preterm infants, we investigated whether prenatal intra-amniotic (IA) inflammation modulates postnatal systemic immune status and organ functions. Preterm pigs exposed to IA lipopolysaccharide (LPS) for 3 days were compared with controls at birth and postnatal day 5 after formula feeding. IA LPS induced mild chorioamnionitis but extensive intra-amniotic inflammation. There were minor systemic effects at birth (increased blood neutrophil counts), but a few days later, prenatal LPS induced delayed neonatal arousal, systemic inflammation (increased blood leukocytes, plasma cytokines, and splenic bacterial counts), altered serum biochemistry (lower albumin and cholesterol and higher iron and glucose values), and increased urinary protein and sodium excretion. In the gut and lungs, IA LPS-induced inflammatory responses were observed mainly at birth (increased LPS, CXCL8, and IL-1β levels and myeloperoxidase-positive cell density, multiple increases in innate immune gene expressions, and reduced villus heights), but not on postnatal day 5 (except elevated lung CXCL8 and diarrhea symptoms). Finally, IA LPS did not affect postnatal gut brush-border enzymes, hexose absorption, permeability, or sensitivity to necrotizing enterocolitis on day 5. Short-term IA LPS exposure predisposes preterm pigs to postnatal systemic inflammation after acute fetal gut and lung inflammatory responses.

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

Although chorioamnionitis (CA) is a well-known risk factor for white matter disease of prematurity, the association with intraventricular hemorrhage (IVH) is controversial and has not been yet systematically reviewed. We performed a systematic review and meta-analysis of studies exploring the association between CA and IVH. A comprehensive literature search was conducted using PubMed/MEDLINE and EMBASE, from their inception to 1 July 2017. Studies were included if they examined preterm infants and reported primary data that could be used to measure the association between exposure to CA and the presence of IVH. A random-effects model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). We found 1,284 potentially relevant studies, of which 85 met the inclusion criteria (46,244 infants, 13,432 CA cases). Meta-analysis showed that CA exposure was significantly associated with all grades IVH (OR 1.88, 95% CI 1.61-2.19), with grades 1-2 IVH (OR 1.69, 95% CI 1.22-2.34), and with grades 3-4 IVH (OR 1.62, 95% CI 1.42-1.85). Both clinical and histological CA were associated with an increased risk for developing IVH in very preterm infants. In contrast, the presence of funisitis did not increase IVH risk when compared to CA in the absence of funisitis (OR 1.22, 95% CI 0.89-1.67). Further meta-analyses confirmed earlier findings that CA-exposed infants have significantly lower gestational age (GA; mean difference [MD] -1.20 weeks) and lower birth weight (BW; MD -55 g) than the infants not exposed to CA. However, meta-regression and subgroup analysis could not demonstrate an association between the lower GA and BW and the risk of IVH in the CA-exposed infants. In conclusion, our data show that CA is a risk factor for IVH, but also a risk factor for greater prematurity and more clinical instability. In contrast to other complications of prematurity, such as patent ductus arteriosus, retinopathy of prematurity, or bronchopulmonary dysplasia, the effect of CA on IVH appears to be independent of CA as causative factor for very preterm birth.

Mid-trimester preterm premature rupture of membranes (PPROM): etiology, diagnosis, classification, international recommendations of treatment options and outcome

Mid-trimester preterm premature rupture of membranes (PPROM), defined as rupture of fetal membranes prior to 28 weeks of gestation, complicates approximately 0.4%-0.7% of all pregnancies. This condition is associated with a very high neonatal mortality rate as well as an increased risk of long- and short-term severe neonatal morbidity. The causes of the mid-trimester PPROM are multifactorial. Altered membrane morphology including marked swelling and disruption of the collagen network which is seen with PPROM can be triggered by bacterial products or/and pro-inflammatory cytokines. Activation of matrix metalloproteinases (MMP) have been implicated in the mechanism of PPROM. The propagation of bacteria is an important contributing factor not only in PPROM, but also in adverse neonatal and maternal outcomes after PPROM. Inflammatory mediators likely play a causative role in both disruption of fetal membrane integrity and activation of uterine contraction. The "classic PPROM" with oligo/an-hydramnion is associated with a short latency period and worse neonatal outcome compared to similar gestational aged neonates delivered without antecedent PPROM. The "high PPROM" syndrome is defined as a defect of the chorio-amniotic membranes, which is not located over the internal cervical os. It may be associated with either a normal or reduced amount of amniotic fluid. It may explain why sensitive biochemical tests such as the Amniosure (PAMG-1) or IGFBP-1/alpha fetoprotein test can have a positive result without other signs of overt ROM such as fluid leakage with Valsalva. The membrane defect following fetoscopy also fulfils the criteria for "high PPROM" syndrome. In some cases, the rupture of only one membrane - either the chorionic or amniotic membrane, resulting in "pre-PPROM" could precede "classic PPROM" or "high PPROM". The diagnosis of PPROM is classically established by identification of nitrazine positive, fern positive watery leakage from the cervical canal observed during in specula investigation. Other more recent diagnostic tests include the vaginal swab assay for placental alpha macroglobulin-1 test or AFP and IGFBP1. In some rare cases amniocentesis and infusion of indigo carmine has been used to confirm the diagnosis of PPROM. The management of the PPROM requires balancing the potential neonatal benefits from prolongation of the pregnancy with the risk of intra-amniotic infection and its consequences for the mother and infant. Close monitoring for signs of chorioamnionitis (e.g. body temperature, CTG, CRP, leucocytes, IL-6, procalcitonine, amniotic fluid examinations) is necessary to minimize the risk of neonatal and maternal complications. In addition to delayed delivery, broad spectrum antibiotics of penicillin or cephalosporin group and/or macrolide and corticosteroids have been show to improve neonatal outcome [reducing risk of chorioamnionitis (average risk ratio (RR)=0.66), neonatal infections (RR=0.67) and abnormal ultrasound scan of neonatal brain (RR=0.67)]. The positive effect of continuous amnioinfusion through the subcutaneously implanted perinatal port system with amniotic fluid like hypo-osmotic solution in "classic PPROM" less than 28/0 weeks' gestation shows promise but must be proved in future prospective randomized studies. Systemic antibiotics administration in "pre-PPROM" without infection and hospitalization are also of questionable benefit and needs to be further evaluated in well-designed randomized prospective studies to evaluate if it is associated with any neonatal benefit as well as the relationship to possible adverse effect of antibiotics on to fetal development and neurological outcome.

Does neutrophil/lymphocyte ratio have good diagnostic value in neonatal necrotizing colitis?

Objective: The diagnostic value of neutrophil/lymphocyte (N/L) ratio in the early diagnosis of neonatal necrotizing colitis (NEC) was evaluated. Methods: This is a cross-sectional study. From the 103 NEC cases, the preterm infants were randomly recruited into this study, including NEC I 41 cases, NEC II 34 cases, and NEC III 28 cases. The control group included 58 preterm infants without NEC. Routine clinical data and blood samples of all NEC patients were collected within 24 h after the established diagnosis of NEC. Besides comparing laboratory data (white blood cell count, C-reactive protein, pre-albumin and N/L ratio) between NEC and control groups, the sensitivity, specificity, and Youden index were also compared. Results: (1) Baseline data including gender, age of admission, and contamination of amniotic fluid showed no difference. But, laboratory data all have significant differences between NEC and control groups (including NEC subgroups analysis). (2) Except pre albumin (PA), there are not significant correlations between N/L ratio and PA, C-reactive protein (CRP) as well as white blood cell count (white blood cell (WBC) count) in NEC stage I. In contrast, good correlation could be found between N/L ratio and other indicators in NEC stage II and stage III. (3) N/L ratio has higher sensitivity, specificity and Youden index when compared with WBC count, CRP, and PA. Conclusion: N/L ratio has better continuity and could be good marker for the early diagnosis of NEC, and could distinguish the severity. However, large sample, multicenter studies are still needed.

Maternal, fetal and perinatal factors associated with necrotizing enterocolitis in Sweden. A national case-control study

OBJECTIVE

To analyze associations of maternal, fetal, gestational, and perinatal factors with necrotizing enterocolitis in a matched case-control study based on routinely collected, nationwide register data.

STUDY DESIGN

All infants born in 1987 through 2009 with a diagnosis of necrotizing enterocolitis in any of the Swedish national health care registers were identified. For each case up to 6 controls, matched for birth year and gestational age, were selected. The resulting study population consisted of 720 cases and 3,567 controls. Information on socioeconomic data about the mother, maternal morbidity, pregnancy related diagnoses, perinatal diagnoses of the infant, and procedures in the perinatal period, was obtained for all cases and controls and analyzed with univariable and multivariable logistic regressions for the whole study population as well as for subgroups according to gestational age.

RESULTS

In the study population as a whole, we found independent positive associations with necrotizing enterocolitis for isoimmunization, fetal distress, cesarean section, neonatal bacterial infection including sepsis, erythrocyte transfusion, persistent ductus arteriosus, cardiac malformation, gastrointestinal malformation, and chromosomal abnormality. Negative associations were found for maternal weight, preeclampsia, maternal urinary infection, premature rupture of the membranes, and birthweight. Different patterns of associations were seen in the subgroups of different gestational age.

CONCLUSION

With some interesting exceptions, especially in negative associations, the results of this large, population based study, are in keeping with earlier studies. Although restrained by the limitations of register data, the findings mirror conceivable pathophysiological processes and underline that NEC is a multifactorial disease.

Paracetamol in Patent Ductus Arteriosus Treatment: Efficacious and Safe?

In preterm infants, failure or delay in spontaneous closure of Ductus Arteriosus (DA), resulting in the condition of Patent Ductus Arteriosus (PDA), represents a significant issue. A prolonged situation of PDA can be associated with several short- and long-term complications. Despite years of researches and clinical experience on PDA management, unresolved questions about the treatment and heterogeneity of clinical practices in different centers still remain, in particular regarding timing and modality of intervention. Nowadays, the most reasonable strategy seems to be reserving the treatment only to hemodynamically significant PDA. The first-line therapy is medical, and ibuprofen, related to several side effects especially in terms of nephrotoxicity, is the drug of choice. Administration of oral or intravenous paracetamol (acetaminophen) recently gained attention, appearing effective as traditional nonsteroidal anti-inflammatory drugs (NSAIDs) in PDA closure, with lower toxicity. The results of the studies analyzed in this review mostly support paracetamol efficacy in ductal closure, with inconstant low and transient elevation of liver enzymes as reported side effect. However, more studies are needed to confirm if this therapy shows a real safety profile and to evaluate its long-term outcomes, before considering paracetamol as first-choice drug in PDA treatment.

Maternal Chorioamnionitis and Postneonatal Respiratory Tract Infection in Ex-Preterm Infants

OBJECTIVE

To assess whether exposure to histologically confirmed chorioamnionitis (ie, histologic chorioamnionitis [HCA]) is associated with altered risk of infection-related hospitalization (IRH) during the first 24 months of life in very preterm infants.

STUDY DESIGN

This single-center retrospective cohort study analyzed data on 1218 infants born at <30 weeks gestational age (GA). Semiquantitative placental histology, obstetric, and neonatal data were extracted from hospital databases and linked with discharge diagnoses on rehospitalization until age 24 months from statewide statutory data. The associations between HCA and overall and clinical categories of IRH were analyzed by Cox proportional hazards regression with left-truncated failure times.

RESULTS

Mean GA was 27 weeks, and HCA was present in 577 placentas (47.4%). Among the 1088 infants surviving until the birth-related discharge, 684 (62.9%) of had at least 1 IRH by age 24 months, of whom 287 included a diagnosis of acute lower respiratory tract infection (ALRTI). Following adjustment for sex, birth weight z-score, GA, early-onset sepsis, late-onset sepsis, previous antibiotic use, age at birth-related discharge, and chronic lung disease, HCA was associated with a 32% increased risk of hospitalization with ALRTI (HR, 1.32; 95% CI, 1.02-1.70; P = .033). There was no association with infection overall or with other infection categories.

CONCLUSIONS

HCA is associated with a significantly increased risk of hospitalization with ALRTI that is independent of known risk factors, including chronic lung disease.

Risk factors for necrotizing enterocolitis in neonates: a systematic review of prognostic studies

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe multifactorial disease in preterm neonates associated with high morbidity and mortality. Better insight into prognostic values of the many reported factors associated with NEC is needed to enable identification of neonates at risk for NEC. The aim was to systematically review the literature to identify independent risk factors for NEC from the literature.

METHODS

Medline, Cochrane, Embase, Pubmed and Google Scholar were searched systematically for cohort studies reporting prognostic factors for NEC in neonates using multivariable analysis. Studies were scored with the Quality In Prognosis Studies tool (QUIPS).

RESULTS

From 5154 initial hits, 14 prognostic studies were included, with various designs. Study quality was rated high in three studies, moderate or low in the 11 others. Significant prognostic factors for NEC reported in at least two studies were: low birth weight, small for gestational age, low gestational age, assisted ventilation, premature rupture of membranes, black ethnicity, sepsis, outborn, hypotension (all increased risk), surfactant therapy (conflicting results) and cesarean section (lower risk). Meta-analysis was considered not feasible.

CONCLUSION

High quality studies on prognostic factors for NEC are rare. Several prognostic factors, that are not necessarily causal, are associated with NEC. High quality prognostic research is necessary to establish the predictive values of these factors.

The Human Ureaplasma Species as Causative Agents of Chorioamnionitis

The human Ureaplasma species are the most frequently isolated microorganisms from the amniotic fluid and placentae of women who deliver preterm and are also associated with spontaneous abortions or miscarriages, neonatal respiratory diseases, and chorioamnionitis. Despite the fact that these microorganisms have been habitually found within placentae of pregnancies with chorioamnionitis, the role of Ureaplasma species as a causative agent has not been satisfactorily explained. There is also controversy surrounding their role in disease, particularly as not all women infected with Ureaplasma spp. develop chorioamnionitis. In this review, we provide evidence that Ureaplasma spp. are associated with diseases of pregnancy and discuss recent findings which demonstrate that Ureaplasma spp. are associated with chorioamnionitis, regardless of gestational age at the time of delivery. Here, we also discuss the proposed major virulence factors of Ureaplasma spp., with a focus on the multiple-banded antigen (MBA), which may facilitate modulation/alteration of the host immune response and potentially explain why only subpopulations of infected women experience adverse pregnancy outcomes. The information presented within this review confirms that Ureaplasma spp. are not simply "innocent bystanders" in disease and highlights that these microorganisms are an often underestimated pathogen of pregnancy.