Clinical chorioamnionitis at term X: microbiology, clinical signs, placental pathology, and neonatal bacteremia - implications for clinical care

Molecular evidence that GBS early neonatal sepsis results from ascending infection: comparative hybrid genomics analyses show that microorganisms in the vaginal ecosystem, amniotic fluid, chorioamniotic membranes, and neonatal blood are the same

OBJECTIVES

Streptococcus agalactiae, or Group B Streptococcus (GBS), is a leading cause of neonatal sepsis. Materno-fetal transmission of the microorganisms present in the lower genital tract/perineum is considered to be the most frequent mode for acquisition of infection. It has also been proposed that, in a subset of cases, GBS causes acute chorioamnionitis, intraamniotic infection, and fetal/neonatal sepsis. However, the evidence to support this ascending pathway is derived from microbiologic studies that rely on cultivation methods, which do not have the resolution to determine if the microorganisms causing neonatal sepsis are the same as those found in the amniotic fluid and the vaginal ecosystem.

METHODS

We used whole genome sequencing of the microorganisms isolated from the vagina, amniotic fluid, chorioamniotic membranes, and neonatal blood (four isolates) in a case of early neonatal sepsis. Using hybrid genome assembly, we characterized the genomic features including virulence factors and antimicrobial resistance in four isolates from the same mother, placenta, and newborn.

RESULTS

Whole genome sequencing revealed that the microorganisms in the four clinical isolates corresponded to S. agalactiae sequence type 1, clonal complexes 1, and serotype Ib. Comparative genomic analysis illustrated similar DNA sequences of the four genomes.

CONCLUSIONS

This study presents the first evidence of the genomic similarity of microorganisms in the vaginal ecosystem, the space between the chorioamniotic membranes of the placenta, amniotic fluid, and neonatal blood.

Quantitative cervicovaginal fluid fetal fibronectin: A liquid biopsy for intra-amniotic inflammation

INTRODUCTION

Intra-amniotic inflammation is causally linked to spontaneous preterm labor. The gold standard for the diagnosis of intra-amniotic inflammation is the determination of an amniotic fluid profile obtained from transabdominal amniocentesis, which is invasive. Cervicovaginal fluid fetal fibronectin (fFN) is a widely-used predictive biomarker for spontaneous preterm labor. The aims of this study are to determine (1) whether a quantitative cervicovaginal fluid fFN test can be used to identify the presence of intra-amniotic inflammation; and (2) an appropriate cut-off value of a cervicovaginal fluid fFN concentration for the identification of intra-amniotic inflammation.

MATERIAL AND METHODS

This prospective cohort study included 78 patients with preterm labor and intact membranes who had a sample collected for quantitative cervicovaginal fluid fFN measurement and underwent transabdominal amniocentesis. Intra-amniotic inflammation was defined as an amniotic fluid interleukin-6 concentration ≥2.6 ng/mL. Clinicians were masked from the results of cervicovaginal fluid fFN and amniotic fluid interleukin-6 concentrations. Logistic regression analysis was used to determine which factors were significant predictors of intra-amniotic inflammation. The diagnostic indices of the cervicovaginal fluid fFN test for the identification of intra-amniotic inflammation were calculated.

RESULTS

(1) Frequency of intra-amniotic inflammation was 26.9% (21/78); (2) the higher the cervicovaginal fluid fFN concentration, the greater the risk of intra-amniotic inflammation (p < 0.001); (3) cervicovaginal fluid fFN concentration ≥125 ng/mL had an area under the curve of 0.91 (95% confidence interval: 0.83-0.96) for the identification of intra-amniotic inflammation with 100% sensitivity, 100% negative predictive value, 82.46% specificity and a positive likelihood ratio of 5.7; and (4) cervicovaginal fluid fFN cut-off of 125 ng/mL had a significant higher predictive performance than the traditional cut-off (50 ng/mL) for the identification of intra-amniotic inflammation.

CONCLUSIONS

Quantitative cervicovaginal fluid fFN with a cut-off of 125 ng/mL had a high sensitivity and a negative predictive value as well as a positive likelihood ratio for the identification of intra-amniotic inflammation. Its high sensitivity and negative predictive value can be used to decrease an index of suspicion of intra-amniotic inflammation. This test may be useful as an initial assessment test to select appropriate patients for amniocentesis to determine intra-amniotic inflammation.

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.

Parturition at term: induction, second and third stages of labor, and optimal management of life-threatening complications-hemorrhage, infection, and uterine rupture

Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information.

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

Clinical chorioamnionitis at term is characterized by changes in the plasma concentration of CHCHD2/MNRR1, a mitochondrial protein

OBJECTIVE

Mitochondrial dysfunction was observed in acute systemic inflammatory conditions such as sepsis and might be involved in sepsis-induced multi-organ failure. Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 2 (CHCHD2), also known as Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1), a bi-organellar protein located in the mitochondria and the nucleus, is implicated in cell respiration, survival, and response to tissue hypoxia. Recently, the reduction of the cellular CHCHD2/MNRR1 protein, as part of mitochondrial dysfunction, has been shown to play a role in the amplification of inflammatory cytokines in a murine model of lipopolysaccharide-induced systemic inflammation. The aim of this study was to determine whether the plasma concentration of CHCHD2/MNRR1 changed during human normal pregnancy, spontaneous labor at term, and clinical chorioamnionitis at term.

METHODS

We conducted a cross-sectional study that included the following groups: 1) non-pregnant women (n = 17); 2) normal pregnant women at various gestational ages from the first trimester until term (n = 110); 3) women at term with spontaneous labor (n = 50); and 4) women with clinical chorioamnionitis at term in labor (n = 25). Plasma concentrations of CHCHD2/MNRR1 were assessed by an enzyme-linked immunosorbent assay.

RESULTS

1) Pregnant women at term in labor with clinical chorioamnionitis had a significantly higher plasma CHCHD2/MNRR1 concentration than those in labor without chorioamnionitis (p = .003); 2) CHCHD2/MNRR1 is present in the plasma of healthy non-pregnant and normal pregnant women without significant differences in its plasma concentrations between the two groups; 3) there was no correlation between maternal plasma CHCHD2/MNRR1 concentration and gestational age at venipuncture; and 4) plasma CHCHD2/MNRR1 concentration was not significantly different in women at term in spontaneous labor compared to those not in labor.

CONCLUSIONS

CHCHD2/MNRR1 is physiologically present in the plasma of healthy non-pregnant and normal pregnant women, and its concentration does not change with gestational age and parturition at term. However, plasma CHCHD2/MNRR1 is elevated in women at term with clinical chorioamnionitis. CHCHD2/MNRR1, a novel bi-organellar protein located in the mitochondria and the nucleus, is released into maternal plasma during systemic inflammation.

Association between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis among patients undergoing induction of labor at term

BACKGROUND

Rectovaginal colonization with Group B Streptococcus during pregnancy has historically been shown to be associated with an increased risk of clinical chorioamnionitis and peripartum infectious morbidity.

OBJECTIVE

Newer observational data in the era of intrapartum antibiotic prophylaxis suggest a possible reversal of this association; however, it is unclear if this is related to differences in labor management for those with and without Group B Streptococcus colonization. We therefore sought to assess the association between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis within the context of a randomized induction of labor trial with a standardized labor protocol.

STUDY DESIGN

We performed an exploratory secondary analysis of a randomized trial of patients undergoing term induction at a tertiary care center. Patients received third trimester Group B Streptococcus screening and intrapartum antibiotic prophylaxis as routine care. Group B Streptococcus detection was performed using a carrot broth-enhanced subculture to Group B Streptococcus Detect approach (Hardy Diagnostics, Santa Maria, CA). Labor management was protocolized per the trial. Patients with unknown Group B Streptococcus status or who did not receive intrapartum antibiotic prophylaxis, if indicated, were excluded. The primary outcome was diagnosis of clinical chorioamnionitis, compared between patients who received intrapartum antibiotic prophylaxis for known Group B Streptococcus positive status (by culture, history, or Group B Streptococcus bacteriuria) and those who were Group B Streptococcus negative and did not receive intrapartum antibiotic prophylaxis. Secondary outcomes included postpartum endometritis, wound infection, a composite maternal peripartum infectious morbidity, and neonatal outcomes.

RESULTS

A total of 491 patients were enrolled in the trial. Of these, 466 had a known Group B Streptococcus status and received or did not receive intrapartum antibiotic prophylaxis accordingly and were included in this analysis: 292 (62.7%) were Group B Streptococcus negative and did not receive intrapartum antibiotic prophylaxis, and 174 (37.3%) were Group B Streptococcus positive and received intrapartum antibiotic prophylaxis. The majority of patients were Non-Hispanic Black (78.1%) and nulliparous (59.7%). There were no differences in demographic, clinical, induction or labor characteristics between groups. Patients who were Group B Streptococcus positive had a 49% lower rate of clinical chorioamnionitis (8.1% vs 14.7%, odds ratio, 0.51; P=.03) and a lower rate of peripartum infectious morbidity (8.1% vs 15.8%, odds ratio, 0.47; P=.02) compared to those who were Group B Streptococcus negative. Infants born to patients who were Group B Streptococcus positive were significantly less likely to be admitted to the neonatal intensive care unit (3.4% vs 15.1%, P<.001).

CONCLUSION

Although Group B Streptococcus colonization has historically been considered a risk factor for clinical chorioamnionitis, in the era of universal antibiotic prophylaxis for Group B Streptococcus positive patients, our findings support the point that intrapartum antibiotic prophylaxis for Group B Streptococcus positivity is associated with lower rates of clinical chorioamnionitis and peripartum infectious morbidity among patients undergoing induction with protocolized labor management. These findings demonstrate that intrapartum antibiotic prophylaxis for Group B Streptococcus may protect against perinatal infectious morbidity, a phenomenon that warrants further investigation.

Laboratory markers to identify acute histological chorioamnionitis in febrile parturients undergoing epidural analgesia: a retrospective study

BACKGROUND

This study aimed to investigate the effect of the pathological staging of acute histological chorioamnionitis (HCA) on laboratory indicators and to conduct further studies to reassess the threshold values used by clinicians to identify acute HCA in febrile parturients undergoing epidural analgesia.

METHODS

A retrospective study of febrile mothers receiving epidural analgesia at Nanjing Maternal and Child Health Care Hospital from January 1, 2018 to December 31, 2018. The participants were grouped by the progression of acute HCA, and the laboratory parameters were compared between groups. The ability of C-reactive protein (CRP), neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and monocyte-leukocyte ratio (M%), alone or in combination, to identify acute HCA in febrile parturients undergoing epidural analgesia was assessed using logistic regression and ROC curves.

RESULTS

The area under the curve (AUC) of the best logistic regression model predicting HCA climbed to 0.706 (CRP + MLR). Maternal CRP, NLR, and MLR significantly and progressively increased with the progression of acute HCA (p < 0.0001). Based on the ROC curves, the following thresholds were selected to define increased laboratory indicators for identifying acute HCA: CRP ≥ 6.90 mg/L, NLR ≥ 11.93, and MLR ≥ 0.57. In addition, the AUC of the best logistic regression model predicting HCA ≥ stage 2 was 0.710, so these inflammatory markers were more precise in predicting HCA ≥ stage 2.

CONCLUSION

Increased CRP (≥ 6.90 mg/L), NLR (≥ 11.93), and MLR (≥ 0.57) may help clinicians to identify early potential acute HCA in febrile parturients receiving epidural analgesia and to monitor progression to optimize clinical treatment options.

TRIAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry on November 24, 2021 ( http://www.chictr.org.cn , ChiCTR2100053554).

Antibiotic treatment of women with isolated intrapartum fever vs clinical chorioamnionitis: maternal and neonatal outcomes

BACKGROUND

Clinical chorioamnionitis refers to the presence of maternal fever (≥38°C) and at least 2 clinical signs: (1) maternal tachycardia (>100 bpm), (2) fetal tachycardia (>160 bpm), (3) maternal leukocytosis >15,000/mm2, (4) purulent vaginal discharge, and (5) uterine tenderness. Few data exist to guide the appropriate management of women with isolated intrapartum fever in the absence of other clinical signs suggesting chorioamnionitis.

OBJECTIVE

This study compared maternal and neonatal infectious outcomes and microbiological outcomes between women with isolated intrapartum fever and women with clinical chorioamnionitis.

STUDY DESIGN

This 10-year retrospective study included all the laboring women at our institution, at ≥34 weeks of gestation, with a singleton pregnancy and body temperature of ≥38.0°C, with or without other evidences of infection. According to our department protocol, women with isolated intrapartum fever received intravenous ampicillin, whereas women with clinical chorioamnionitis received intravenous ampicillin plus gentamicin. The primary outcome was puerperal endometritis, compared between women with isolated intrapartum fever (treated with ampicillin) and women with clinical chorioamnionitis (treated with ampicillin plus gentamicin). The secondary maternal outcomes consisted of (1) maternal clinical outcomes, such as cesarean delivery, surgical site infection, postpartum hemorrhage, and postpartum length of stay, and (2) microbiological studies, including positive chorioamniotic membrane swabs and blood culture. Among the secondary neonatal outcomes were early-onset sepsis, neonatal intensive care unit admission, and length of stay. Of note, 2 multivariate logistic regression models were created. A model aimed to predict puerperal endometritis controlled for gestational age of >41 weeks, diabetes mellitus, obesity, positive group B streptococcus status, rupture of membrane ≥18 hours, meconium staining, positive chorioamniotic membrane swabs, cesarean delivery, and empiric postdelivery antibiotic administration. A model aimed to predict neonatal early-onset sepsis controlled for gestational age of 34 to 37 weeks, positive group B streptococcus status, rupture of membrane ≥18 hours, and positive chorioamniotic membrane swabs.

RESULTS

Overall, 458 women met the inclusion criteria. Compared with women with clinical chorioamnionitis (n=231), women with isolated intrapartum fever (n=227) had higher rates of puerperal endometritis (3.9% vs 8.8%; P=.03), early-onset sepsis (0.4% vs 4.4%; P=.005), positive chorioamniotic membrane swabs (46.3% vs 63.9%; P<.001), and ampicillin-resistant Escherichia coli (35.5% vs 48.9%; P=.033). The rate of group B streptococcus-positive chorioamniotic membrane swabs was similar between the groups. In a subanalysis of women with negative or unknown group B streptococcus status, the puerperal endometritis and neonatal early-onset sepsis rates were higher among women with isolated intrapartum fever than women with suspected chorioamnionitis (8.7% vs 3.3% [P=.041] and 4.1% vs 0% [P<.001], respectively). In 2 multivariate analysis models, among women with isolated intrapartum fever treated with ampicillin compared with those with clinical chorioamnionitis treated with ampicillin and gentamicin, the odds ratio of antibiotic treatment of endometritis was 2.65 (95% confidence interval, 1.06-6.62; P=.036), and the odds ratio of neonatal early-onset sepsis was 8.33 (95% confidence interval, 1.04-60.60; P=.045).

CONCLUSION

Women with intrapartum fever, with or without other signs of infection, were at increased risk of maternal and neonatal complications. The use of ampicillin as a sole agent in isolated intrapartum fever might promote ampicillin-resistant E coli growth in the chorioamniotic membranes and consequently lead to puerperal endometritis and early-onset sepsis. In this context, a broad-range antibiotic should be considered.

Antigen-specific decidual CD8+ T cells include distinct effector memory and tissue-resident memory cells

Maternal decidual CD8+ T cells must integrate the antithetical demands of providing immunity to infection while maintaining immune tolerance for fetal and placental antigens. Human decidual CD8+ T cells were shown to be highly differentiated memory T cells with mixed signatures of dysfunction, activation, and effector function. However, no information is present on how specificity for microbial or fetal antigens relates to their function or dysfunction. In addition, a key question, whether decidual CD8+ T cells include unique tissue-resident memory T cells (Trm) or also effector memory T cell (Tem) types shared with peripheral blood populations, is unknown. Here, high-dimensional flow cytometry of decidual and blood CD8+ T cells identified 2 Tem populations shared in blood and decidua and 9 functionally distinct Trm clusters uniquely found in decidua. Interestingly, fetus- and virus-specific decidual CD8+ Trm cells had similar features of inhibition and cytotoxicity, with no significant differences in their expression of activation, inhibitory, and cytotoxic molecules, suggesting that not all fetus-specific CD8+ T cell responses are suppressed at the maternal-fetal interface. Understanding how decidual CD8+ T cell specificity relates to their function and tissue residency is crucial in advancing understanding of their contribution to placental inflammation and control of congenital infections.

Implementation of a 24-hour empiric antibiotic duration for negative early-onset sepsis evaluations to reduce early antibiotic exposure in premature infants

OBJECTIVE

Antibiotic exposure increases the risk of morbidity and mortality in premature infants. Many centers use at least 48 hours of antibiotics in the evaluation of early-onset sepsis (EOS, <72 hours after birth), yet most important pathogens grow within 24 hours. We investigated the safety and efficacy of reducing empiric antibiotic duration to 24 hours.

DESIGN

Quality improvement study.

SETTING

A tertiary-care neonatal intensive care unit.

PATIENTS

Inborn infants <35 weeks gestational age at birth (ie, preterm) admitted January 2019 through December 2020.

INTERVENTION

In December 2019, we changed the recommended duration of empiric antibiotics for negative EOS evaluations from 48 hours to 24 hours.

RESULTS

Patient characteristics before and after the intervention were similar. After the intervention, 71 preterm infants (57%) with negative EOS evaluations received ≤24 hours of antibiotics, an increase from 15 (10%) before the intervention. These 71 infants comprised 77% of infants with negative EOS blood cultures after excluding those treated as clinical sepsis (≥5 days of antibiotics). For all negative EOS blood cultures, the mean treatment duration decreased by 0.5 days from 3.9 days to 3.4 days. This finding equated to 2.4 fewer antibiotic days per 100 patient days for negative EOS blood cultures but similar antibiotic days per 30 patient days (7.2 days vs 7.5 days). This measure did not change over time. Subsequent sepsis evaluations <7 days after a negative EOS blood culture did not increase. Excluding contaminants, the median time to positivity was 13.2 hours (range, 8-23) in 8 positive blood cultures.

CONCLUSION

Implementation of a 24-hour antibiotic course for negative EOS evaluations safely reduced antibiotic exposure in 77% of infants <35 weeks gestational age at birth in whom EOS was ruled out. All clinically significant pathogens grew within 24 hours.

Intra-Amniotic Inflammation or Infection: Suspected and Confirmed Diagnosis of "Triple I" at Term

Chorioamnionitis (CA) at term of pregnancy can have an infectious and/or inflammatory origin and is associated with adverse outcomes. Triple I (intrauterine inflammation, infection, or both, TI) has been proposed to reduce the overdiagnosis of infection and neonatal overtreatment. The aim of this study is to identify clinical and histological variables that could predict adverse outcomes when TI is suspected and/or confirmed. This retrospective cohort study included 404 pregnancies (gestational age ≥ 37 weeks) that were divided into 5 all-inclusive and mutually exclusive groups. TI was defined according to the NICHD definition of 2015, and it could be confirmed (TI+) or not confirmed (TI-) via histological examination. Signs of infection/inflammation that did not conform to the definition of TI were classified as "clinical suspicion" and could be supported (CS+) or not supported (CS-) by histology. Cases of histological chorioamnionitis (HCA) without clinical manifestation represented a fifth group. Whole placental involvement (WPLI) was defined as a histological inflammation involving the maternal and fetal sides. There were 113 TI+, 30 TI-, 186 CS+, 35 CS-, and 40 isolated HCA cases. WPLI was diagnosed in 133 cases (39.2%). Composite neonatal outcome (CNO) occurred in 114 cases (28.2%) while composite maternal outcome (CMO) occurred in 192 cases (47.5%). Compared with CS+, TI+ was more predictive of CNO (p = 0.001), CMO (p < 0.001), and WPLI (p = 0.005). WPLI was related both to CNO (p < 0.001) and to CMO (p = 0.046). TI+ and WPLI showed similar sensitivity but different specificity in predicting CNO. At logistic regression, CNO was independently predicted by TI+ (OR 2.21; p = 0.001) and by WPLI (OR 2.23; p = 0.001). Compared with CS, TI is a better predictor of CNO and can be useful for the identification of newborns at risk.

Pathophysiological interpretation of fetal heart rate tracings in clinical practice

The onset of regular, strong, and progressive uterine contractions may result in both mechanical (compression of the fetal head and/or umbilical cord) and hypoxic (repetitive and sustained compression of the umbilical cord or reduction in uteroplacental oxygenation) stresses to a human fetus. Most fetuses are able to mount effective compensatory responses to avoid hypoxic-ischemic encephalopathy and perinatal death secondary to the onset of anaerobic metabolism within the myocardium, culminating in myocardial lactic acidosis. In addition, the presence of fetal hemoglobin, which has a higher affinity for oxygen even at low partial pressures of oxygen than the adult hemoglobin, especially increased amounts of fetal hemoglobin (ie, 180-220 g/L in fetuses vs 110-140 g/L in adults), helps the fetus to withstand hypoxic stresses during labor. Different national and international guidelines are currently being used for intrapartum fetal heart rate interpretation. These traditional classification systems for fetal heart rate interpretation during labor are based on grouping certain features of fetal heart rate (ie, baseline fetal heart rate, baseline variability, accelerations, and decelerations) into different categories (eg, category I, II, and III tracings, "normal, suspicious, and pathologic" or "normal, intermediary, and abnormal"). These guidelines differ from each other because of the features included within different categories and because of their arbitrary time limits stipulated for each feature to warrant an obstetrical intervention. This approach fails to individualize care because the "ranges of normality" for stipulated parameters apply to the population of human fetuses and not to the individual fetus in question. Moreover, different fetuses have different reserves and compensatory responses and different intrauterine environments (presence of meconium staining of amniotic fluid, intrauterine inflammation, and the nature of uterine activity). Pathophysiological interpretation of fetal heart rate tracing is based on the application of the knowledge of fetal responses to intrapartum mechanical and/or hypoxic stress in clinical practice. Both experimental animal studies and observational human studies suggest that, just like adults undertaking a treadmill exercise, human fetuses show predictable compensatory responses to a progressively evolving intrapartum hypoxic stress. These responses include the onset of decelerations to reduce myocardial workload and preserve aerobic metabolism, loss of accelerations to abolish nonessential somatic body movements, and catecholamine-mediated increases in the baseline fetal heart rate and effective redistribution and centralization to protect the fetal central organs (ie, the heart, brain, and adrenal glands), which are essential for intrauterine survival. Moreover, it is essential to incorporate the clinical context (progress of labor, fetal size and reserves, presence of meconium staining of amniotic fluid and intrauterine inflammation, and fetal anemia) and understand the features suggestive of fetal compromise in nonhypoxic pathways (eg, chorioamnionitis and fetomaternal hemorrhage). It is important to appreciate that the timely recognition of the speed of onset of intrapartum hypoxia (ie, acute, subacute, and gradually evolving) and preexisting uteroplacental insufficiency (ie, chronic hypoxia) on fetal heart rate tracing is crucial to improve perinatal outcomes.

Leveraging the placenta to advance neonatal care

The impact of placental dysfunction and placental injury on the fetus and newborn infant has become a topic of growing interest in neonatal disease research. However, the use of placental pathology in directing or influencing neonatal clinical management continues to be limited for a wide range of reasons, some of which are historical and thus easily overcome today. In this review, we summarize the most recent literature linking placental function to neonatal outcomes, focusing on clinical placental pathology findings and the most common neonatal diagnoses that have been associated with placental dysfunction. We discuss how recent technological advances in neonatal and perinatal medicine may allow us to make a paradigm shift, in which valuable information provided by the placenta could be used to guide neonatal management more effectively, and to ultimately enhance neonatal care in order to improve our patient outcomes. We propose new avenues of clinical management in which the placenta could serve as a diagnostic tool toward more personalized neonatal intensive care unit management.

Maternal fever in labor: etiologies, consequences, and clinical management

Intrapartum fever is common and presents diagnostic and treatment dilemmas for the clinician. True maternal sepsis is rare; only an estimated 1.4% of women with clinical chorioamnionitis at term develop severe sepsis. However, the combination of inflammation and hyperthermia adversely impacts uterine contractility and, in turn, increases the risk for cesarean delivery and postpartum hemorrhage by 2- to 3-fold. For the neonate, the rates of encephalopathy or the need for therapeutic hypothermia have been reported to be higher with a maternal fever >39°C when compared with a temperature of 38°C to 39°C (1.1 vs 4.4%; P<.01). In a large cohort study, the combination of intrapartum fever and fetal acidosis was particularly detrimental. This suggests that intrapartum fever may lower the threshold for fetal hypoxic brain injury. Because fetal hypoxia is often difficult to predict or prevent, every effort should be made to reduce the risk for intrapartum fever. The duration of exposure to epidural analgesia and the length of labor in unmedicated women remain significant risk factors for intrapartum fever. Therefore, paying careful attention to maintaining labor progress can potentially reduce the rates of intrapartum fever and the risk for cesarean delivery if fever does occur. A recent, double-blind randomized trial of nulliparas at >36 weeks' gestation demonstrated that a high-dose oxytocin regimen (6×6 mU/min) when compared with a low-dose oxytocin regimen (2×2 mU/min) led to clinically meaningful reductions in the rate of intrapartum fever (10.4% vs 15.6%; risk rate, 0.67; 95% confidence interval, 0.48-0.92). When fever does occur, antibiotic treatment should be initiated promptly; acetaminophen may not be effective in reducing the maternal temperature. There is no evidence that reducing the duration of fetal exposure to intrapartum fever prevents known adverse neonatal outcomes. Therefore, intrapartum fever is not an indication for cesarean delivery to interrupt labor with the purpose of improving neonatal outcome. Finally, clinicians should be ready for the increased risk for postpartum hemorrhage and have uterotonic agents on hand at delivery to prevent delays in treatment.

Maternal plasma cytokines and the subsequent risk of uterine atony and postpartum hemorrhage

OBJECTIVES

To determine whether the maternal plasma concentrations of cytokines are higher in pregnant women with postpartum hemorrhage (PPH) compared to pregnant women without PPH.

METHODS

A retrospective case-control study included 36 women with PPH and 72 matched controls. Cases and controls were matched for gestational age at delivery, labor status, delivery route, parity, and year of sample collection. Maternal plasma samples were collected up to 3 days prior to delivery. Comparison of the plasma concentrations of 29 cytokines was performed by using linear mixed-effects models and included adjustment for covariates and multiple testing. A false discovery rate adjusted p-value <0.1 was used to infer significance. Random forest models with evaluation by leave-one-out and 9-fold cross-validation were used to assess the combined value of the proteins in predicting PPH.

RESULTS

Concentrations of interleukin (IL)-16, IL-6, IL-12/IL-23p40, monocyte chemotactic protein 1 (MCP-1), and IL-1β were significantly higher in PPH than in the control group. This difference remained significant after adjustment for maternal age, clinical chorioamnionitis, and preeclampsia. Multi-protein random forest proteomics models had moderate cross-validated accuracy for prediction of PPH [area under the ROC curve, 0.69 (0.58-0.81) by leave-one-out cross validation and 0.73 (0.65-0.81) by 9-fold cross-validation], and the inclusion of clinical and demographic information did not increase the prediction performance.

CONCLUSIONS

Pregnant women with severe PPH had higher median maternal plasma concentrations of IL-16, IL-6, IL-12/IL-23p40, MCP-1, and IL-1β than patients without PPH. These cytokines could serve as biomarkers or their pathways may be therapeutic targets.

Clinical characteristics and predictors of neonatal outcomes in chorioamnionitis at term gestation: A cohort study

OBJECTIVE

To investigate the association between clinical and laboratory characteristics of chorioamnionitis in deliveries at term gestation with adverse neonatal outcomes.

DESIGN

Retrospective cohort study.

SETTING

The study is based on data from the Swedish Pregnancy Register, enriched with clinical data extracted from medical charts.

SAMPLE

A cohort of 500 term singleton deliveries in Stockholm County with registered diagnosis of chorioamnionitis (based on the assessment of the responsible obstetrician) in the Swedish Pregnancy Register between 2014 and 2020.

METHODS

Logistic regression was used to estimate odds ratios (ORs) as a measurement of the association between clinical and laboratory characteristics and neonatal complications.

MAIN OUTCOME MEASURES

Neonatal infection and asphyxia-related complications.

RESULTS

The prevalence of neonatal infection and asphyxia-related complications was 10% and 22%, respectively. First leukocyte count in the second tertile (OR 2.14, 95% CI 1.02-4.49), maximum C-reactive protein (CRP) level in the third tertile (OR 4.01, 95% Cl 1.66-9.68) and positive cervical culture (OR 2.22, 95% Cl 1.10-4.48) were associated with an increased risk of neonatal infection. Maximum level of CRP in the third tertile (OR 1.93, 95% Cl 1.09-3.41) and fetal tachycardia (OR 1.63, 95% Cl 1.01-2.65) were associated with an increased risk of asphyxia-related complications.

CONCLUSIONS

Elevated inflammatory laboratory markers were associated with both neonatal infection and asphyxia-related complications, and fetal tachycardia was associated with asphyxia-related complications. Based on these findings, the incorporation of maternal CRP in the management of chorioamnionitis should be considered, and a continuous communication between obstetric and neonatal care extending past the delivery time point endorsed.

A randomized clinical trial of antibiotic treatment duration in preterm premature rupture of membranes: 7 days vs until delivery

BACKGROUND

Antibiotic treatment in preterm premature rupture of membranes can prolong the interval from membrane rupture to delivery and improve neonatal outcomes. However, the duration of antibiotic treatment for preterm premature rupture of membranes has been rarely compared in prospective studies.

OBJECTIVE

This study aimed to investigate the optimal duration of antibiotic treatment for premature rupture of membranes. We performed a randomized controlled trial comparing neonatal morbidity and infantile neurologic outcomes between 2 groups of patients with preterm premature rupture of membranes who received antibiotic treatment for 7 days or until delivery, respectively.

STUDY DESIGN

This prospective randomized study included patients who were diagnosed with preterm premature rupture of membranes between 22+0 weeks and 33+6 weeks of gestation. The enrolled patients were randomly assigned to receive intravenous cefazolin (1 g dosage every 12 hours) and oral clarithromycin (500 mg dosage every 12 hours) either for 7 days or until delivery. The study protocol was registered at ClinicalTrials.gov under identifier NCT01503606. The primary outcome was a neonatal composite morbidity, and the secondary outcome was neurologic outcomes at 12 months of corrected age. We enrolled 151 patients and allocated 75 and 76 of them to the 7-day and until-delivery groups, respectively. Analysis was done by per protocol.

RESULTS

After excluding cases lost to follow-up and those with protocol violations, 63 (7-day regimen) and 61 (until-delivery regimen) patients with preterm premature rupture of membranes and their babies were compared. There was no significant difference in the pregnancy outcomes, including gestational age at delivery and the interval from rupture of membranes to delivery, between the 2 groups. Among the neonatal outcomes, bronchopulmonary dysplasia, intraventricular hemorrhage, retinopathy of prematurity, necrotizing enterocolitis, and proven neonatal sepsis did not differ between the groups. However, the rates of respiratory distress syndrome (32.8% vs 50.8%; P=.039) and composite neonatal morbidities (34.4% vs 53.9%; P=.026) were lower in the until-delivery group than in the 7-day group. This difference remained statistically significant after a multivariable analysis adjusting for maternal age, twin pregnancy, antenatal corticosteroids treatment, gestational age at delivery, interval from rupture of membranes to delivery, and clinical chorioamnionitis. Infantile neurologic outcomes were evaluated in 71.4% of the babies discharged alive and did not differ between the groups.

CONCLUSION

Overall, the until-delivery regimen of cefazolin and clarithromycin in preterm premature rupture of membranes led to a lower incidence of composite neonatal morbidity and respiratory distress syndrome than the 7-day regimen, and both regimens otherwise showed similar individual neonatal morbidities and infantile neurologic outcomes.

The role of upper and lower genital tract microbiota alterations in term chorionamnionitis: A prospective study

Objective

This study aimed to compare the dynamics of lower and upper genital tract microbiota in normal term pregnancy, histological chorioamnionitis (HCA), and clinical chorioamnionitis (CCA) patients to provide a reference for the diagnosis and treatment of chorioamnionitis (CAM) patients.

Methods

We prospectively collected vaginal and cervical secretions, as well as placenta tissues, fetal membranes, and amniotic fluid from normal-term pregnant women, HCA and CCA patients. Then, we performed genomic DNA extraction and PCR amplification for all samples. The eligible samples were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Additionally, all placenta tissues were histopathologically examined, and neonatal pharyngeal swabs and placenta tissues from the HCA and CCA groups were subjected to microbial culture.

Results

A total of 85 term pregnant women were enrolled in this study, including 34 in the normal group (N), 37 in the HCA group, and 14 in the CCA group. A total of 171 qualified samples were analyzed by 16S rRNA sequencing. The results suggested that the cervical microbiota was highly similar to the vaginal microbiota in normal term parturients, with Lactobacillus as the dominant bacterium. Moreover, there was no difference in the alpha and beta diversity of vaginal microbiota between the N, HCA, and CCA groups at the genus level. Besides, no significant differences were detected in cervical microbiome among the three groups. Regarding intrauterine microorganisms, the N and HCA groups had similar microbial composition but were different from the CCA group. No microbe was detected in the placental tissue of normal term parturients, while some microorganisms were found in the intrauterine amniotic fluid and fetal membrane samples. Regardless of cultivation or 16S rRNA sequencing, an extremely low microbial positive rate was detected in HCA and CCA intrauterine samples. Compared to the normal group, Lactobacillus was significantly reduced in the CCA group intrauterine, and Ureaplasma and Enterococcus increased with no statistically significant.

Conclusion

The N, HCA and CCA groups had similar composition of vaginal and cervical microflora. Some normal-term pregnant women can harbor non-pathogenic microbiota in the uterine cavity. Sterile inflammation is more frequent than microbial-associated inflammation in term HCA and CCA parturients.

Rapid diagnosis of intra-amniotic infection using nanopore-based sequencing

OBJECTIVES

Early diagnosis and treatment of intra-amniotic infection is crucial. Rapid pathogen identification allows for a definite diagnosis and enables proper management. We determined whether the 16S amplicon sequencing performed by a nanopore sequencing technique make possible rapid bacterial identification at the species level in intra-amniotic infection.

METHODS

Five cases of confirmed intra-amniotic infection, determined by either cultivation or 16S rDNA polymerase chain reaction (PCR) Sanger sequencing, and 10 cases of women who underwent mid-trimester genetic amniocentesis were included. DNA was extracted from amniotic fluid and PCR was performed on the full-length 16S rDNA. Nanopore sequencing was performed. The results derived from nanopore sequencing were compared with those derived from cultivation and Sanger sequencing methods.

RESULTS

Bacteria were successfully detected from amniotic fluid using nanopore sequencing in all cases of intra-amniotic infection. Nanopore sequencing identified additional bacterial species and polymicrobial infections. All patients who underwent a mid-trimester amniocentesis had negative cultures, negative 16S PCR Sanger sequencing and nanopore sequencing. Identification of the microorganisms using nanopore sequencing technique at the bacterial species level was achieved within 5-9 h from DNA extraction.

CONCLUSIONS

This is the first study demonstrating that the nanopore sequencing technique is capable of rapid diagnosis of intra-amniotic infection using fresh amniotic fluid samples.

Does acute funisitis predict worse neonatal outcomes among term newborns?

BACKGROUND

Acute funisitis-the histologic diagnosis of inflammation within the umbilical cord-represents a fetal inflammatory response to infection. Although acute funisitis has been associated with an increased risk of adverse outcomes among preterm neonates, there are limited and conflicting data with term deliveries.

OBJECTIVE

This study aimed to evaluate the association between acute funisitis and neonatal morbidity in neonates born at term to pregnant patients with a clinical diagnosis of intraamniotic infection.

STUDY DESIGN

This was a retrospective cohort study of pregnant patients who had clinically diagnosed intraamniotic infection at term, delivered vaginally at a single tertiary institution from 2013 to 2019, and had histologic chorioamnionitis on placental pathology. Patients with intrauterine fetal demise or missing neonatal/placental pathology data were excluded. The primary outcome was a neonatal sepsis composite, defined as culture-positive bacteremia, neutropenia (absolute neutrophil count<3500/μL), or immature-to-total neutrophil ratio>0.2. The secondary outcomes included composite neonatal morbidity, defined as neonatal intensive care unit admission, 5-minute Apgar score <7, bacteremia, endotracheal intubation or need for continuous positive airway pressure, intraventricular hemorrhage (grade 3 or 4), necrotizing enterocolitis (stage 3 or 4), umbilical artery pH<7.1, umbilical artery base excess>12, and neonatal mortality. The components of these composites, neonatal intensive care unit length of stay, and Kaiser early-onset sepsis score were also measured. Neonates with acute funisitis on pathology were compared with those without acute funisitis using bivariate statistics. Regression was used to estimate the relative risk of outcomes.

RESULTS

Of 184 neonates with deliveries complicated by intraamniotic infection, acute funisitis was present in 109 (59%) placental specimens. Composite neonatal sepsis was significantly higher among neonates with acute funisitis (relative risk, 1.85; 95% confidence interval, 1.13-3.03) than in those without acute funisitis. As a marker for sepsis, acute funisitis has a sensitivity of 39.4%, negative predictive value of 47.2%, specificity of 78.7%, and positive predictive value of 72.9%. An immature-to-total neutrophil ratio>0.2 (relative risk, 1.83; 95% confidence interval, 1.09-3.08) was also significantly associated with acute funisitis. Neonatal morbidity composite, intraventricular hemorrhage, necrotizing enterocolitis, neonatal intensive care unit admission, higher Kaiser early-onset sepsis scores, and other examined outcomes were not statistically associated with acute funisitis.

CONCLUSION

In term deliveries complicated by intraamniotic infection, acute funisitis was associated with increased neonatal sepsis. Current approaches for estimating neonatal sepsis risk are limited by their reliance on indirect maternal factors such as maximum maternal temperature and intrapartum antibiotic use. This study suggests that acute funisitis may serve as a marker that could be utilized to augment risk stratification at birth if a protocol for evaluating the umbilical cord in real-time were widely adopted.

Antimicrobial Peptides in Early-Life Host Defense, Perinatal Infections, and Necrotizing Enterocolitis—An Update

Host defense against early-life infections such as chorioamnionitis, neonatal sepsis, or necrotizing enterocolitis (NEC) relies primarily on innate immunity, in which antimicrobial peptides (AMPs) play a major role. AMPs that are important for the fetus and neonate include α and β defensins, cathelicidin LL-37, antiproteases (elafin, SLPI), and hepcidin. They can be produced by the fetus or neonate, the placenta, chorioamniotic membranes, recruited neutrophils, and milk-protein ingestion or proteolysis. They possess antimicrobial, immunomodulating, inflammation-regulating, and tissue-repairing properties. AMPs are expressed as early as the 13th week and increase progressively through gestation. Limited studies are available on AMP expression and levels in the fetus and neonate. Nevertheless, existing evidence supports the role of AMPs in pathogenesis of chorioamnionitis, neonatal sepsis, and NEC, and their association with disease severity. This suggests a potential role of AMPs in diagnosis, prevention, prognosis, and treatment of sepsis and NEC. Herein, we present an overview of the antimicrobial and immunomodulating properties of human AMPs, their sources in the intrauterine environment, fetus, and neonate, and their changes during pre- and post-natal infections and NEC. We also discuss emerging data regarding the potential utility of AMPs in early-life infections, as diagnostic or predictive biomarkers and as therapeutic alternatives or adjuncts to antibiotic therapy considering the increase of antibiotic resistance in neonatal intensive care units.

Azithromycin reduces inflammation-amplified hypoxic-ischemic brain injury in neonatal rats

BACKGROUND

Systemic inflammation amplifies neonatal hypoxic-ischemic (HI) brain injury. Azithromycin (AZ), an antibiotic with anti-inflammatory properties, improves sensorimotor function and reduces tissue damage after neonatal rat HI brain injury. The objective of this study was to determine if AZ is neuroprotective in two neonatal rat models of inflammation-amplified HI brain injury.

DESIGN/METHODS

Seven-day-old (P7) rats received injections of toll-like receptor agonists lipopolysaccharide (LPS) or Pam₃Cys-Ser-(Lys)₄ (PAM) prior to right carotid ligation followed by 50 min (LPS + HI) or 60 min (PAM + HI) in 8% oxygen. Outcomes included contralateral forelimb function (forepaw placing; grip strength), survival, %Intact right hemisphere (brain damage), and a composite score incorporating these measures. We compared postnatal day 35 outcomes in controls and groups treated with three or five AZ doses. Then, we compared P21 outcomes when the first (of five) AZ doses were administered 1, 2, or 4 h after HI.

RESULTS

In both LPS + HI and PAM + HI models, AZ improved sensorimotor function, survival, brain tissue preservation, and composite scores. Benefits increased with five- vs. three-dose AZ and declined with longer initiation delay.

CONCLUSIONS

Perinatal systemic infection is a common comorbidity of neonatal asphyxia brain injury and contributes to adverse outcomes. These data support further evaluation of AZ as a candidate treatment for neonatal neuroprotection.

IMPACT

AZ treatment decreases sensorimotor impairment and severity of brain injury, and improves survival, after inflammation-amplified HI brain injury, and this can be achieved even with a 2 h delay in initiation. This neuroprotective benefit is seen in models of inflammation priming by both Gram-negative and Gram-positive infections. This extends our previous findings that AZ treatment is neuroprotective after HI brain injury in neonatal rats.

Chorioamnionitis and risk of long-term neurodevelopmental disorders in offspring: a population-based cohort study

BACKGROUND

Evidence indicates that in utero exposure to chorioamnionitis might increase the risk of neurodevelopmental disorders in the offspring. However, findings on this topic have been inconsistent.

OBJECTIVE

To examine the association between chorioamnionitis and neurodevelopmental disorders in offspring.

STUDY DESIGN

This was a retrospective population-based cohort study in Sweden. A total of 2,228,280 singleton live births and stillbirths between 1998 and 2019 were included in our study population. Data on maternal characteristics and neurodevelopmental disorders in offspring were obtained by individual record-linkages of nationwide Swedish registries. Chorioamnionitis was identified using the National Medical Birth Register. Inpatient and outpatient diagnoses were obtained for cerebral palsy, autism, attention deficit hyperactivity disorder, epilepsy, and intellectual disability. Multivariable Cox proportional hazards regression was used to estimate the association between chorioamnionitis and each neurodevelopmental disorder with adjusted hazard ratios and 95% confidence intervals. A causal mediation analysis of the relationship between chorioamnionitis and neurodevelopmental disorders with preterm delivery (<37 weeks) was performed.

RESULTS

A total of 5770 (0.26%) offspring were exposed to chorioamnionitis during pregnancy. During the study's follow-up time there were 4752 (0.21%) cases of cerebral palsy, 17,897 (0.80 %) cases of epilepsy, 50,570 (2.27 %) cases of autism, 114,087 (5.12%) cases of attention deficit hyperactivity disorder, and 14,574 (0.65%) cases of intellectual disability. After adjusting for potential confounders, exposure to chorioamnionitis increased the hazard ratios of cerebral palsy (adjusted hazard ratio, 7.43; 95% confidence interval, 5.90-9.37), autism (adjusted hazard ratio, 1.43; 95% confidence interval, 1.21-1.68), attention deficit hyperactivity disorder (adjusted hazard ratio, 1.17; 95% confidence interval, 1.03-1.33), and intellectual disability (adjusted hazard ratio, 1.99; 95% confidence interval, 1.53-2.58), whereas chorioamnionitis was not significantly associated with higher rates of epilepsy in offspring. Mediation analysis revealed that these associations were mainly explained through preterm delivery; however, increased risk was also observed among term infants.

CONCLUSION

Chorioamnionitis increases the risk of neurodevelopmental disorders, particularly cerebral palsy, autism, attention deficit hyperactivity disorder, and intellectual disability. These associations were mainly mediated through preterm delivery. Efforts for timely identification and appropriate interventions to treat infections during pregnancy will have sustained benefits in reducing the burden of neurologic complications in children at the population level.

Bacteria in the amniotic fluid without inflammation: early colonization vs. contamination

OBJECTIVES

Intra-amniotic infection, defined by the presence of microorganisms in the amniotic cavity, is often accompanied by intra-amniotic inflammation. Occasionally, laboratories report the growth of bacteria or the presence of microbial nucleic acids in amniotic fluid in the absence of intra-amniotic inflammation. This study was conducted to determine the clinical significance of the presence of bacteria in amniotic fluid samples in the absence of intra-amniotic inflammation.

METHODS

A retrospective cross-sectional study included 360 patients with preterm labor and intact membranes who underwent transabdominal amniocentesis for evaluation of the microbial state of the amniotic cavity as well as intra-amniotic inflammation. Cultivation techniques were used to isolate microorganisms, and broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was utilized to detect the nucleic acids of bacteria, viruses, and fungi.

RESULTS

Patients whose amniotic fluid samples evinced microorganisms but did not indicate inflammation had a similar perinatal outcome to those without microorganisms or inflammation [amniocentesis-to-delivery interval (p=0.31), spontaneous preterm birth before 34 weeks (p=0.83), acute placental inflammatory lesions (p=1), and composite neonatal morbidity (p=0.8)].

CONCLUSIONS

The isolation of microorganisms from a sample of amniotic fluid in the absence of intra-amniotic inflammation is indicative of a benign condition, which most likely represents contamination of the specimen during the collection procedure or laboratory processing rather than early colonization or infection.

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.