Impact of different stages of intrauterine inflammation on outcome of preterm neonates: Gestational age-dependent and -independent effect

The effect of histological and subclinical chorioamnionitis and funisitis on breathing effort in premature infants at birth: a retrospective cohort study

Antenatal inflammation in the form of chorioamnionitis (fetal membranes; HCA) and funisitis (umbilical vessels; FUN) is a major risk factor for preterm birth. Exposure to HCA + FUN affects infants by releasing mediators that may suppress respiratory drive. While the association between clinical chorioamnionitis (CCA) and (depressed) spontaneous breathing has been described, we have investigated the association between breathing and HCA + FUN. Infants born < 30 weeks' gestation with available placental pathology assessments were included. Infants were compared at multiple levels: infants with vs without HCA + FUN (comparison 1) and infants with subclinical HCA + FUN vs infants without any chorioamnionitis (comparison 2). The primary outcome was breathing effort, defined as minute volume (MV) of spontaneous breathing in the first 5 min after birth. We also assessed tidal volume (Vt), respiratory rate (RR), heart rate (HR), oxygen saturation (SpO2) and oxygen requirement (FiO2). Regression analyses were performed to control for confounding factors. One hundred eighty-six infants were included (n = 75 infants with HCA + FUN vs. n = 111 infants without HCA + FUN). Comparison 1: Infants with HCA + FUN had lower gestational ages 26+5 (25+0-28+1; median (IQR) and lower birthweights (mean ± SD; 943 ± 264) compared to infants without HCA + FUN (28+4 (27+0-29+1) weeks, p < 0.001 and 1023 ± 270 g, p = 0.049). Comparison 2: Subclinical HCA + FUN was diagnosed in 46/75 HCA + FUN infants. Infants with subclinical HCA + FUN had lower gestational ages (26+6 (25+1-28+3) vs. 28+4 (27+2-29+1) weeks, p < 0.001) without significant differences for birthweights (987 ± 248 vs. 1027 ± 267 g, p = 0.389) compared to infants without any chorioamnionitis (n = 102 infants). After adjustment, HCA + FUN was associated with lower MV (p = 0.025), but subclinical HCA + FUN was not (p = 0.226). HCA + FUN and subclinical HCA + FUN were associated with lower Vt (p = 0.003; p = 0.014), SpO2 at 5 min (p = 0.021; 0.036) and SpO2/FiO2 ratio (p = 0.028; p = 0.040).

CONCLUSION

HCA + FUN and subclinical HCA + FUN are associated with reduced oxygenation and parameters that reflect breathing effort in premature infants at birth.

WHAT IS KNOWN

• Acute antenatal inflammation, in the form of chorioamnionitis (fetal membranes) and funisitis (umbilical vessels), affects a large proportion of premature infants. • Clinical chorioamnionitis is associated with reduced breathing effort and oxygenation in premature infants at birth.

WHAT IS NEW

• Histological and subclinical chorioamnionitis and funisitis are associated with reduced breathing effort parameters and oxygenation in premature infants at birth.

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.

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

OBJECTIVE

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

DATA SOURCES

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

STUDY ELIGIBILITY CRITERIA

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

METHODS

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

RESULTS

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

CONCLUSION

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

Histological Chorioamnionitis and Funisitis as New Risk Factors for Retinopathy of Prematurity: A Meta-analysis

OBJECTIVE

 The role of placental inflammation in neonatal morbidities is underestimated due to lack of placental examination. This meta-analysis aims to assess the association between histological chorioamnionitis (HCA) with and without funisitis (FUN) and risk of retinopathy of prematurity (ROP).

STUDY DESIGN

 Forty-five studies reporting (unadjusted) data on HCA without FUN and HCA with FUN in neonates with ROP were included. Primary outcomes were any stage ROP and severe ROP. Potential confounders explored were gestational age (GA) at birth, birthweight, maternal steroid use, necrotizing enterocolitis, sepsis (suspected/proven) and mechanical ventilation duration.

RESULTS

 Neonates with HCA had increased risk for any stage ROP (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.4) and severe ROP (OR 1.5; 95% CI 1.2-1.8) compared with neonates without HCA. The rates of any stage ROP (OR 1.8; 95% CI 1.4-2.2) and severe ROP (OR 1.4; 95% CI 1.1-1.6) were higher in neonates with FUN compared with neonates without FUN. Multivariate meta-regression analysis suggests that lower GA increases the effect size between FUN and severe ROP.

CONCLUSION

 This meta-analysis confirms that presence of HCA and FUN are risk factors for any stage ROP and severe ROP. Structured histological placental examination of HCA and FUN may be a tool to further refine the ROP risk profile.

KEY POINTS

· This systematic review confirms that HCA is a risk factor for ROP.. · This meta-analysis reveals that FUN results in an even higher risk for developing ROP.. · Placental examination of HCA/FUN may be a tool to further refine the ROP risk profile..

Perinatal risk factors for neonatal early-onset sepsis: a meta-analysis of observational studies

OBJECTIVE

Early-onset neonatal sepsis (EONS) remains an important cause of neonatal mortality and has many risk factors, therefore, this study aimed to investigate the perinatal risk factors for EONS.

METHODS

We searched CNKI, Wan Fang, VIP, CBM, PubMed, Embase, and Web of Science to compile studies regarding the incidence of neonatal early-onset sepsis, published up to 1 May 2022. To evaluate the quality of the included studies, we used the Newcastle-Ottawa Scale, and the RevMan5.3 software was used for meta-analysis.

RESULTS

A total of 17 studies were included, with 1987 cases in the case group and 4814 cases in the control group. Meta-analysis showed that perinatal asphyxia or intrauterine distress (OR = 3.00, 95% CI: 2.18-4.13), amniotic fluid meconium contamination (OR = 4.51, 95% CI: 2.31-8.81), group B streptococcal (GBS) colonization in pregnant women (OR = 2.13, 95% CI: 1.48-3.05), chorioamnionitis (OR = 4.58, 95% CI: 2.61-8.05), premature rupture of membranes (OR = 2.63, 95% CI: 2.09-3.30), lower gestational age (OR = 1.31, 95% CI: 1.18-1.44), maternal urinary or reproductive tract infection (OR = 3.61, 95% CI: 2.14-6.11), perinatal fever (OR = 3.59, 95% CI: 2.25-5.71), very low birth weight (OR = 3.79, 95% CI: 2.14-6.73), and vaginal examination ≥3 times (OR = 7.95, 95% CI: 4.04-15.64) were the perinatal risk factors for EONS.

CONCLUSION

Perinatal asphyxia or intrauterine distress, meconium contamination in amniotic fluid, GBS colonization in pregnant women, chorioamnionitis, premature rupture of membranes, lower gestational age, maternal urinary tract or reproductive tract infection, perinatal fever, very low birth weight, and vaginal examinations ≥3 times may increase the risk of EONS.

Cord blood granulocyte Colony-Stimulating factor level as an optimal predictor of umbilical cord arteritis associated with brain injury at term equivalent age in preterm neonates

OBJECTIVE

The study aimed 1) to evaluate the association between the presence or absence of umbilical cord arteritis (UCA) and the cord blood cytokine levels, and 2) morbidity and mortality of preterm neonates; and 3) to identify predictive markers for UCA of preterm neonates.

STUDY DESIGN

In this single-center retrospective observational cohort study, preterm neonates born at gestational age (GA) < 36 weeks were categorized pathologically according to the severity of intrauterine inflammation; those without UCA as Group 1, those with UCA as Group 2, and those without any intrauterine inflammation as Group 3 (control), and subgroup analyses classified by their GA were performed. We compared morbidity and mortality, and eight representative cytokine levels in cord blood samples between the groups. Subsequently, receiver operating characteristics (ROC) curves for UCA diagnosis for each cytokine were created, and values of areas under the curve (AUC) were calculated to determine the optimal predictive markers.

RESULTS

In total, 105 patients (36, 58, and 11 in Groups 1, 2, and 3, respectively) were included. Multivariate logistic analysis revealed that patients with UCA had higher incidence of brain injury (Odds Ratio [OR] = 8.53, P = 0.0049, 95% Confidence Interval [CI]: 1.91 - 38.0), at term equivalent age in the subgroup analysis with GA < 32 weeks. Although the median value of cord blood granulocyte colony-stimulating factor (G-CSF) was significantly higher in Group 2 than in Group 1 or 3, only the G-CSF level was found to be high in the subgroup analysis with GA < 32 weeks. For UCA diagnosis, the AUC values of G-CSF were the highest among eight cytokines including interleukin 6 (IL-6). These findings were similar in the subgroup analysis with GA < 32 weeks.

CONCLUSIONS

Preterm neonates, especially born at GA < 32 week, had higher morbidity from　brain injury in the group with UCA. The cord blood G-CSF level was highly accurate for predicting UCA and could thus be used as an optimal biomarker.

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

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

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.

Effect of clinical chorioamnionitis on breathing effort in premature infants at birth: a retrospective case-control study

RATIONALE

Antenatal inflammation, usually associated with chorioamnionitis, is a major cause of premature birth. As inflammation could depress respiratory drive, we have examined the effect of clinical chorioamnionitis (CCA) on spontaneous breathing in premature infants at birth.

METHODS

Infants with CCA born <30 weeks' gestation were matched with control infants based on gestational age (±6 days), birth weight (±300 g), antenatal corticosteroids, sex and general anaesthesia. The primary outcome was breathing effort, assessed as minute volume (MV) of spontaneous breathing. We also measured tidal volume (Vt), respiratory rate (RR) and apnoea in the first 5 min and additional physiological parameters in the first 10 min after start of respiratory support.

RESULTS

Ninety-two infants were included (n=46 CCA infants vs n=46 controls; median (IQR) gestational age 26⁺⁴ (25⁺⁰-27⁺⁶) vs 26⁺⁶ (25⁺¹-28⁺³) weeks). MV and Vt were significantly lower (MV: 43 (17-93) vs 70 (31-119) mL/kg/min, p=0.043; Vt: 2.6 (1.9-3.6) vs 2.9 (2.2-4.8) mL/kg/breath, p=0.046), whereas RR was similar in CCA infants compared with controls. Incidence of apnoea was higher (5 (2-6) vs 2 (1-4), p=0.002), and total duration of apnoea was longer (90 (21-139) vs 35 (12-98) s, p=0.025) in CCA infants. CCA infants took significantly longer to reach an oxygen saturation >80% (3:37 (2:10-4:29) vs 2:25 (1:06-3:52) min, p=0.016) and had a lower oxygen saturation at 5 min (77 (66-92) vs 91 (68-94) %, p=0.028), despite receiving more oxygen (62 (48-76) vs 54 (43-73) %, p=0.036).

CONCLUSION

CCA is associated with reduced breathing effort and oxygenation in premature infants at birth.

The Association of Patent Ductus Arteriosus with Inflammation: A Narrative Review of the Role of Inflammatory Biomarkers and Treatment Strategy in Premature Infants

Patent ductus arteriosus (PDA) is a common cardiovascular complication that complicates clinical care in the intensive care of premature infants. Prenatal and postnatal infections and the inflammation process can contribute to PDA, and intrauterine inflammation is a known risk factor of PDA. A variety of inflammatory biomarkers have been reported to be associated with PDA. Chorioamnionitis induces the fetal inflammatory process via several cytokines that have been reported to be associated with the presence of PDA and may have a role in the vascular remodeling process or vessel dilation of the ductus. On the other hand, anti-inflammatory agents, such as antenatal steroids, decrease PDA incidence and severity in patients born to those with chorioamnionitis. Proinflammatory cytokines, which are expressed more significantly in preterm neonates and chorioamnionitis, are associated with the presence of PDA. In this review, we focus on the pathogenesis of PDA in preterm infants and the role of biomarkers associated with the perinatal inflammatory process.

Risk factors and bronchopulmonary dysplasia severity: data from the Spanish Bronchopulmonary Dysplasia Research Network

GEIDIS is a national-based research-net registry of patients with bronchopulmonary dysplasia (BPD) from public and private Spanish hospitals. It was created to provide data on the clinical characterization and follow-up of infants with BPD until adulthood. The purpose of this observational study was to analyze the characteristics and the impact of perinatal risk factors on BPD severity. The study included 1755 preterm patients diagnosed with BPD. Of the total sample, 90.6% (n = 1591) were less than 30 weeks of gestation. The median gestational age was 27.1 weeks (25.8-28.5) and median birth weight 885 g (740-1,070 g). A total of 52.5% (n = 922) were classified as mild (type 1), 25.3% (n = 444) were moderate (type 2), and 22.2% (n = 389) were severe BPD (type 3). In patients born at under 30 weeks' gestation, most pre-and postnatal risk factors for type 2/3 BPD were associated with the length of exposure to mechanical ventilation (MV). Independent prenatal risk factors were male gender, oligohydramnios, and intrauterine growth restriction. Postnatal risk factors included the need for FiO2 of > 0.30 in the delivery room, nosocomial pneumonia, and the length of exposure to MV. Conclusion: In this national-based research-net registry of BPD patients, the length of MV is the most important risk factor associated with type 2/3 BPD. Among type 3 BPD patients, those who required an FiO2 > .30 at 36 weeks' postmenstrual age had a higher morbidity, during hospitalization and at discharge, compared to those with nasal positive pressure but FiO2 < .30. What is Known: • BPD is a highly complex multifactorial disease associated with preterm birth. What is New: • The length of exposure to mechanical ventilation is the most important postnatal risk factor associated to bronchopulmonary severity which modulate the effect of most pre and postnatal risk factors. • Among patients with BPD, the requirement for FiO2 >.30% at 36 weeks of postmenstrual age is associated with greater morbidity during hospitalization and at discharge.

Delivery indication matters for perinatal outcomes in late preterm newborns

BACKGROUND

The late preterm (LP) rate in Western countries is 3-6% of all births, accounting for about two-thirds of the entire preterm population. However, all LP babies are not the same.

AIMS

To identify pregnancies at risk for adverse outcomes in the LP period, we investigated how gestational age (GA) at delivery, delivery indication and prenatal risk factors may affect neonatal outcomes.

STUDY DESIGN

Prospective cohort study among singleton infants born between 34 + 0 and 36 + 6 weeks, in Emilia Romagna, Italy, during 2013-2015.

OUTCOMES MEASURES

The primary outcome was a composite of adverse perinatal outcomes. Multivariate logistic regression models were used to, respectively, investigate the effects of GA at delivery, circumstances at parturition and prenatal risk factors, on study outcomes after controlling for confounding variable.

RESULTS

Among 1867 births, 302, 504, and 1061 infants were born at 34, 35, and 36 weeks, respectively. There were no neonatal deaths. An increased risk of composite neonatal outcome was observed among 34 and 35 weeks deliveries compared with 36 weeks, and among indicated deliveries compared with spontaneous. When studying prenatal risk factors, neonatal morbidity was associated with pre gestational diabetes, preterm premature rupture of membranes (pPROM), maternal obesity, bleeding and polyhydramnios; instead, preeclampsia had a protective effect.

CONCLUSION

LP with indicated deliveries at 34 or 35 weeks, or with specific prenatal risk factors have worse neonatal outcome when compared to 36. Such differences should be considered when counseling patients and planning interventions such as timing of delivery in LP period.

Exposure to intrauterine inflammation and late-onset sepsis in very preterm infants

BACKGROUND

Late-onset sepsis is an important cause of mortality and morbidity in preterm infants. As these infants rely mostly on their innate immune system to fight off infection, enhancing this immune system by appropriate stimuli may prevent late-onset sepsis. However, it remains unclear which stimuli can enhance the neonatal immune system. This study aims to investigate the influence of intrauterine inflammation on late-onset sepsis.

METHODS

This is a retrospective cohort study in a Neonatal Intensive Care Unit in the Netherlands. Between 2005 and 2016, 1014 infants with ≤32 weeks gestational age and/or with a birth weight ≤1500 g were included. Intrauterine inflammation was subdivided into histological chorioamnionitis, fetal inflammatory response, and funisitis. Logistic and Cox regression analyses were performed to investigate the influence of intrauterine inflammation on late-onset sepsis.

RESULTS

Thirty-six percent of the included infants developed late-onset sepsis; 24% of placentas showed intrauterine inflammation. Late-onset sepsis incidence did not differ between infants with or without exposure to intrauterine inflammation after adjustment for gestational age (histological chorioamnionitis aHR 0.928 [CI: 0.727-1.185], p = 0.551; fetal inflammatory response aHR 1.011 [CI: 0.793-1.288], p = 0.930); funisitis aHR 0.965 [CI: 0.738-1.263], p = 0.797).

CONCLUSIONS

Late-onset sepsis in very preterm infants seems not to be associated with intrauterine inflammation.

IMPACT

Intrauterine inflammation is not protective of developing late-onset sepsis in premature infants. A large cohort study on the effect of intrauterine inflammation on neonatal outcome. This study adds to existing knowledge on finding appropriate stimuli to enhance the immune system of premature infants to improve neonatal outcome.

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.

Histological chorioamnionitis and its impact on respiratory outcome in very-low-birth-weight preterm infants

BACKGROUND

The role of intrauterine infection in the development of neonatal pulmonary disease is unclear and the impact of histological chorioamnionitis (HCAM) on respiratory outcomes in preterm infants remains controversial. The aim of this study was to explore the association between HCAM and neonatal respiratory outcomes in very-low-birth-weight (VLBW) preterm infants and evaluate the stepwise difference in the stage and severity of HCAM among neonatal respiratory outcomes.

METHODS

We retrospectively enrolled 129 VLBW preterm infants with placenta histopathology examinations in this study. HCAM was subdivided into 3 stages (early, intermediate, and advanced) according to the progression of the maternal inflammatory response. The perinatal characteristics, placental histopathology, and neonatal morbidities, including respiratory outcomes (respiratory distress syndrome (RDS), Wilson-Mikity syndrome (WMS) and bronchopulmonary dysplasia (BPD)), were collected for comparison.

RESULTS

A total of 52.7% (68/129) of the infants had HCAM, including 23 early (stage 1), 30 intermediate (stage 2), and 15 advanced (stage 3) stage. There was no significant difference in the gestational age, birth body weight or mortality rate between the HCAM and non-HCAM groups. Mothers with HCAM had a significantly lower incidence of pre-eclampsia but a higher rate of premature rupture of membrane. They also had higher WBC counts and C-reactive protein levels before delivery. Neonates with HCAM had a lower incidence of RDS but were at a higher risk for developing WMS and BPD. After multivariate analysis adjustment, HCAM was still negatively associated with RDS (aOR = .069, p < .001) but without correlation with BPD. However, neonates with intermediate to advanced-stage HCAM had a higher risk of developing WMS and increased home oxygen usage rate compared to those with early-stage HCAM.

CONCLUSION

HCAM has a protective effect from RDS in preterm neonates. Additionally, VLBW neonates with intermediate to advanced-stage HCAM are at risk for WMS.

Clinically relevant umbilical cord inflammation identified based on CD15-associated vasculitis patterning

INTRODUCTION

Acute funisitis, a granulocyte-related inflammation of the umbilical cord, is associated with chorioamnionitis and perinatal adverse events. However, there is no efficient procedure for detecting clinically relevant umbilical cord inflammation. The objective of this study was to identify such inflammation, based on immunohistochemical assessment of umbilical cord vasculitis patterns.

METHODS

Accordingly, 261 cases were retrieved from a single medical institute. Using the well-established granulocyte marker CD15, we developed a five-tier umbilical cord inflammation-scoring system. Additionally, previous morphological assessments from pathological reports were compared to the immunohistochemical findings.

RESULTS

Analysis of results based on our new scoring system revealed that severe umbilical phlebitis (score 3) was significantly associated with maternal inflammatory response and that severe umbilical arteriophlebitis (score 4) was correlated with low umbilical arterial blood pH, a feature linked to fetal mortality and morbidity. These results corresponded with and were validated by the morphology-based assessments. Additionally, immunohistochemical analysis revealed the clinical and pathological relevance of vitelline vasculitis, a recently proposed condition. We found that analyzing three umbilical cord sections enabled superior detection of severe umbilical vasculitis than analyzing two sections. However, whether these sections were sampled from multiple distant sites or a single localized site did not significantly affect the detection of clinically relevant inflammation.

DISCUSSION

CD15 immunohistochemistry is a potent tool for observing the patterns of clinically relevant umbilical vasculitis, especially in cases that were indeterminate according to morphology alone. Sampling three umbilical cord sections was an efficient procedure for addressing the spatial heterogeneity of umbilical cord inflammation. CD15 immunohistochemistry is a potent tool for observing the patterns of clinically relevant umbilical vasculitis, especially in cases that were indeterminate according to morphology alone. Sampling three umbilical cord sections was an efficient procedure for addressing the spatial heterogeneity of umbilical cord inflammation.

Earlier preterm birth is associated with a worse neurocognitive outcome in a rabbit model

Background

Preterm birth (PTB) and particularly late preterm PTB has become a research focus for obstetricians, perinatologists, neonatologists, pediatricians and policy makers alike. Translational models are useful tools to expedite and guide clinical but presently no model exists that contextualizes the late PTB scenario. Herein we aimed to develop a rabbit model that echo’s the clinical neurocognitive phenotypes of early and late PTB.

Methods

Time mated rabbit does underwent caesarean delivery at a postconceptional age (PCA) of either 28 (n = 6), 29 (n = 5), 30 (n = 4) or 31 (n = 4) days, term = 31 d. Newborn rabbits were mixed and randomly allocated to be raised by cross fostering and underwent short term neurobehavioral testing on corrected post-natal day 1. Open field (OFT), spontaneous alteration (TMT) and novel object recognition (NORT) tests were subsequently performed at 4 and 8 weeks of age.

Results

PTB was associated with a significant gradient of short-term mortality and morbidity inversely related to the PCA. On postnatal day 1 PTB was associated with a significant sensory deficit in all groups but a clear motor insult was only noted in the PCA 29d and PCA 28d groups. Furthermore, PCA 29d and PCA 28d rabbits had a persistent neurobehavioral deficit with less exploration and hyperanxious state in the OFT, less alternation in TMT and lower discriminatory index in the NORT. While PCA 30d rabbits had some anxiety behavior and lower spontaneous alteration at 4 weeks, however at 8 weeks only mild anxiety driven behavior was observed in some of these rabbits.

Conclusions

In this rabbit model, delivery at PCA 29d and PCA 28d mimics the clinical phenotype of early PTB while delivery at PCA 30d resembles that of late PTB. This could serve as a model to investigate perinatal insults during the early and late preterm period.

Adverse Maternal and Neonatal Outcomes in Women With Elevated Intrapartum Temperature Complicated by Histological Chorioamnionitis at Term: A Propensity-Score Matched Study

Background: Elevated intrapartum temperature has been widely proven to be associated with adverse clinical outcomes in both mothers and neonates. Histological chorioamnionitis (HCA), the inflammation of chorion and amniotic membranes, is commonly observed in those with elevated intrapartum temperature. Thus, we aimed to explore whether the combination of HCA would further affect the pregnancy outcomes in those with intrapartum temperature ≥ 37.5°C. Methods: This retrospective cohort study was conducted at the International Peace Maternity and Child Health Hospital (IPMCH), including all full-term women with intrapartum temperature ≥ 37.5°C from Jan 2017 to Jan 2019. Patients were divided in to HCA group or control group according to placental pathology results, and we used 1:1 propensity score matching (PSM) to reduce the effects of potential confounding factors between the two groups. Univariate and multivariable logistic regression were used to identify the association between HCA and different adverse maternal and neonatal outcomes. Results: We formed a propensity-score matched cohort containing 464 women in each group. Higher positive rate of mycoplasma (14.01% vs. 7.33%, p = 0.001) was found in the vaginal secretion culture of women in the HCA group. After adjusting for various baseline clinical characteristics, women with HCA were more likely to end their delivery by cesarean section (AOR = 1.55, 95% CI: 1.05-2.28), and puerperal morbidity (AOR = 2.77, 95% CI: 1.44-5.33) as well as prolonged hospitalization (AOR = 1.56, 95% CI: 1.12-2.17) were more likely to be observed in the HCA group. The existence of HCA might also be associated with neonatal sepsis (AOR = 2.83, 95% CI: 1.14-7.04) and NICU admission (AOR = 1.40, 95% CI: 1.04-1.87) in newborns. In the study on the impact of different stages of HCA, we found that both maternal and neonatal outcomes would not be affected by mild HCA (stage I), while HCA of stage III was associated with increased need for neonatal respiratory support and elevated likelihood of prolonged hospitalization in neonates. Conclusions: Elevated intrapartum temperature complicated by HCA might be related to the elevated occurrence of several adverse maternal and neonatal outcomes, except those with HCA of stage I. Advanced HCA stage correlated with a worse prognosis.

The effect of concomitant histologic chorioamnionitis in pregnancies complicated by fetal growth restriction

INTRODUCTION

We aimed to investigate the effect of placental histologic chorioamnionitis (HC) on neonatal outcomes in pregnancies complicated by fetal growth restriction (FGR).

METHODS

- The computerized medical files of all pregnancies diagnosed with FGR (birthweight <10th percentile) at 24-42 weeks of gestation between 2008 and 2019 were reviewed. Maternal and neonatal outcomes were compared between FGR with and without evidence of placental HC. Placental lesions were classified according to "Amsterdam" criteria. Composite adverse neonatal outcome-included any of the following complications: neurological morbidity, neonatal respiratory assistance, RDS, NEC, sepsis, blood transfusion, phototherapy, hypoglycemia, or neonatal death. Composite severe adverse neonatal outcome included any of the following complications - neurological morbidity, blood transfusion, NEC, sepsis, RDS, neonatal death.

RESULTS

- Compared to FGR without HC (n = 446), FGR with HC (n = 57) was characterized by more advanced gestational age at delivery 39.2 (38.3-39.9) vs. 38.2 (36.9-39.2), weeks respectively, p < 0.001), higher rate of nulliparity (73.7% vs. 45.1%, p < 0.001), less vascular lesions of MVM (1.8% vs.11.2%, p = 0.02), higher rate of Apgar scores at 5 min <7 (10.5% vs. 2%, p = 0.004), increased neonatal death (7.0% vs. 0.9%, p = 0.007), higher rates of both composite adverse neonatal outcome (31.1% vs. 17.3% p = 0.02), and composite severe adverse neonatal outcome (16.3% vs. 8.2% p = 0.04). By multivariate regression analysis HC was found to be independently associated with composite adverse neonatal outcome (aOR = 1.21, 95% CI 1.08-2.38) and with severe composite adverse neonatal outcome (aOR = 1.39, 95% CI 1.16-3.76).

CONCLUSIONS

Pregnancies complicated by FGR with concomitant HC were associated with higher rates of adverse neonatal outcomes.

Early- and Late-Respiratory Outcome in Very Low Birth Weight with or without Intrauterine Inflammation

• IUI is a risk factor for spontaneous preterm birth and contributes to prematurity-associated mortality and morbidity.• HCA greatly affected Apgar's score and lung management of VLBWI at birth and later on with increased incidence of BPD.• HCA + FUN did not significantly impact on respiratory outcome.

OBJECTIVE

Intrauterine inflammation or infection (IUI) is a risk factor for spontaneous preterm birth and contributes to prematurity-associated mortality and morbidity. IUI can include inflammation, as well as infections of varying degrees of severity and duration. Histological chorioamnionitis (HCA) remains the "gold standard" for the diagnosis but clinical, microbiological, and biochemical criteria are often used to define chorioamnionitis. The impact of intrauterine inflammation on respiratory outcome, in infants with very low birth weight, is still unclear and previous data are conflicting showing increase, decrease, or no risk of respiratory complications.

STUDY DESIGN

This is a retrospective study aimed to investigate the role of IUI on neonatal respiratory outcome. Histological criteria (HCA alone and HCA + funisitis [FUN]) and "intrauterine inflammation or infection or both" "Triple I" definition were used; different management in delivery room, in the first 7 days of life (early outcome) and incidence of mild, moderate, and severe bronchopulmonary dysplasia (BPD; late outcome) were considered.

RESULTS

A total of 162 infants with very low birth weight (VLBW) with placenta histology were enrolled. Suspected TRIPLE or fever alone was present in 7.4%, and confirmed TRIPLE or HCA in 29.6% of cases (HCA alone 19.1% vs. HCA + FUN 10.5%). Preterm premature rupture of membrane (p-PROM) was strongly associated with HCA (66.6% in HCA group) and HCA was present in 80% neonates born between 22 and 24 weeks of gestational age (GA). HCA group (GA, 26 weeks; birth weight [BW], 880 g) showed lower Apgar's score, higher intubation rate, and need of ventilation in delivery room, surfactant, duration of noninvasive ventilation (NIV), severe patent ductus arteriosus (PDA), and incidence of BPD compared with no-HCA (GA, 30 weeks; BW, 1,210 g). Length of hospital stay and mortality were higher in HCA group (p = 0.01) and an increasing trend was present for HCA + FUN compared with HCA alone.

CONCLUSION

HCA greatly affected Apgar's score and lung management of VLBW infants (VLBWI) at birth and later on with increased incidence of BPD, thus impacting length of stay and quality of life, while HCA + FUN did not significantly impact on respiratory outcome. Further studies are needed to clarify the role of HCA and FUN in VLBW neonates.

Placental histopathological features of fetoscopic laser photocoagulation for monoaminotic diamniotic twin pregnancies

INTRODUCTION

This study aimed to compare the histopathological placental features of monochorionic diamniotic (MCDA) twins who did and did not undergo fetoscopic laser photocoagulation (FLP).

METHODS

This was a retrospective single-institution cohort study on MCDA twins who underwent FLP between October 2010 and December 2018. The control group included MCDA twins who did not undergo FLP and were delivered during the same period in the institute. The incidence of chorioamnionitis (CAM), funisitis, and other pathological findings was compared between the FLP and control groups after matching by gestational age at delivery.

RESULTS

In total, 292 MCDA pregnant women who underwent FLP and 356 controls gave birth during the study period. After matching the two groups in the ratio 1:1 by gestational age at delivery, each group comprised 194 subjects. The incidence of histological CAM with Blanc association (stage I, 6.2% vs. 3.1%, crude odds ratio (cOR) = 3.1, P = 0.052; stage II, 7.2% vs. 5.7%, cOR = 1.6, P = 0.30; stage III, 2.1% vs. 2.6%, cOR = 0.66, P = 0.52) and funisitis (artery, 5.2% vs. 3.6%, cOR = 1.3, P = 0.63; vein 7.2% vs. 4.1%, cOR = 1.6, P = 0.29) was not statistically significant difference between the FLP and control groups. The FLP group demonstrated a higher incidence of partial placental infarction than the control group (10.3% vs. 3.1%, cOR = 4.3, P = 0.004, adjusted OR = 2.8, P = 0.031).

DISCUSSION

FLP did not appear to increase the incidence of histological CAM or funisitis in subjects matched by gestational age at delivery. The FLP group demonstrated a higher incidence of partial placental infarction than the control group.

Efficacy of Aflibercept Treatment and Its Effect on the Retinal Perfusion in the Oxygen-Induced Retinopathy Mouse Model of Retinopathy of Prematurity

INTRODUCTION

Bevacizumab and ranibizumab, which are anti-vascular endothelial growth factor (VEGF) medications, are used frequently in the treatment for retinopathy of prematurity (ROP) in infants. Aflibercept, or VEGF Trap, has been used anecdotally, but translation and clinical studies are lacking.

OBJECTIVE

This study investigates the efficacy of aflibercept at reducing areas of non-perfused retina and studies its effect on normal angiogenesis in the oxygen-induced retinopathy mouse model of ROP.

METHODS

C57BL/6 J mice were assigned to room air control (n = 21 eyes) or hyperoxia with 75% oxygen (n = 84 eyes). The hyperoxic mice were assigned to 1 of 3 groups: 0 ng (n = 14 eyes), 100 ng (n = 35 eyes), or 1,000 ng (n = 35 eyes) of intravitreal aflibercept administered on postnatal day 14. Eyes were enucleated at PN17 and PN25 postinjection. Retinas were stained with anti-collagen IV antibody and photographed with microscopy. Areas of perfused and non-perfused retina were quantified using ImageJ software. Statistical comparisons were made using ANOVA with Tukey post hoc comparisons.

RESULTS

At PN17, there was no significant difference in the area of non-perfused retina between the hyperoxic control and the 100 and 1,000 ng aflibercept groups. At PN25, the 100 ng (p < 0.05) and 1,000 ng (p = 0.008) treatment groups displayed less non-perfusion compared to hyperoxic controls. At the 1,000 ng dose, there was increased non-perfusion compared to the 100 ng dose (p = 0.02). There was reduced non-perfusion by PN25 compared to PN17 for the 100 ng group (p < 0.05), with no difference in the 1,000 ng group.

CONCLUSIONS

The study shows that the area of non-perfused retina decreases effectively with aflibercept at PN25 with 100 ng dosage. With the 1,000 ng dosage, there is an inhibition of the physiologic angiogenesis with a higher area of non-perfused retina.