Maternal blood C-reactive protein, white blood cell count, and temperature in preterm labor: a comparison with amniotic fluid white blood cell count

Diagnostic tests for the prediction of histological chorioamnionitis and funisitis in pregnant women with preterm premature rupture of membranes: A systematic review

BACKGROUND

Infection of the amniotic cavity is an important driver and/or consequence of preterm prelabour rupture of membranes (PPROM). Prediction of infection is challenging, limiting guidance for interventions during the antenatal period. Infection typically triggers a host inflammatory response, and non-invasive indirect markers of the maternal or fetal inflammatory response have been reported in the context of PPROM and intra-amniotic infection. Some of these markers have also been tested in amniotic fluid (AF) samples.

AIMS

This study compared markers of the inflammatory response in women with PPROM against the outcome standard of histological chorioamnionitis (HCA) or funisitis (FUS).

METHODS

Searches were conducted for studies reporting diagnostic test sensitivity and specificity for proven HCA or FUS in pregnant women with PPROM after 20 weeks' gestation. Weighted mean pooled sensitivity (Se), specificity (Sp), positive predictive value, negative predictive value, diagnostic odds ratio and 95% confidence intervals were calculated for each of the selected diagnostic tests.

RESULTS

Except ultrasonographic detection of fetal thymic involution, almost all index tests analysed showed relatively low sensitivity. Maternal white cell count, interleukin-6 (IL-6) and AF IL-6 had credible specificity. Testing of AF markers, while more consistent than serum markers, showed no clear diagnostic accuracy improvement.

CONCLUSIONS

There is a clear lack of evidence for the reliability of any individual diagnostic test to assist in the detection of HCA or FUS in women with PPROM. Combining several markers into a predictive model for improved diagnosis may be worth investigating.

The Intensity of BCL2A1 Expression Increases According to the Stage Progression of Acute Histologic Chorioamnionitis in the Extra-Placental Membranes of Spontaneous Preterm Birth

Our prior findings showed that BCL2A1 in neutrophils is highly expressed in the extra-placental membranes (EPMs) of both the human spontaneous preterm-birth (PTB) (i.e., PTL or preterm PROM) and nonhuman-primate PTB model. However, no data exist on whether the intensity of BCL2A1 expression quantitatively increases according to the stage progression of acute histologic chorioamnionitis (acute HCA) in EPM. The objective is to investigate whether the intensity of BCL2A1 expression quantitatively increases according to the stage progression of acute HCA in EPM among spontaneous PTB cases, as measured using QuPath. The study population included 121 singleton PTBs (gestational age [GA] at delivery < 34 weeks) due to either preterm labor or preterm PROM. With digital image analysis, we calculated the percentage of BCL2A1-positive cells in immunohistochemistry according to the stage progression of acute HCA in EPMs as the primary outcome and examined the relationship between the percentage of BCL2A1-positive cells and either the GA at delivery or the amniotic-fluid (AF) WBC count as the secondary outcome. The median percentage of BCL2A1-positive cells progressively increases with the stage progression of acute HCA in EPM (group-1 vs. group-2 vs. group-3 vs. group-4 vs. group-5; 7.62 vs. 5.15 vs. 43.57 vs. 71.07; γ = 0.552, p < 0.000001). The percentage of BCL2A1-positive cells in EPMs and the AFWBC count shows a positive correlation (γ = 0.492, p = 0.000385). Moreover, the percentage of BCL2A1-positive cells in EPMs continuously decreased with increasing GA at delivery (γ = -0.253, p = 0.005148). In conclusion, the intensity of BCL2A1 expression increases according to the stage progression of acute HCA in EPMs and the elevation of AFWBC among spontaneous PTB cases. This finding suggests BCL2A1 in EPMs may be a promising marker and target for acute HCA.

Rescue Cerclage in Women With Acute Cervical Insufficiency and Intra-Amniotic Inflammation: A Retrospective Cohort Study

BACKGROUND

To assess the effectiveness of rescue cerclage concerning pregnancy and neonatal outcomes in women with acute cervical insufficiency (CI) complicated with intra-amniotic inflammation (IAI) compared with those managed expectantly.

METHODS

This retrospective cohort study included 87 consecutive singleton pregnant women (17-25 weeks) with acute CI who underwent amniocentesis to assess IAI. Amniotic fluid (AF) samples were assayed for interleukin-6 to define IAI (≥ 2.6 ng/mL). Primary and secondary outcomes were assessed in a subset of CI patients with IAI. The primary outcome measures were spontaneous preterm birth (SPTB) at < 28 and < 34 weeks, and the secondary outcomes were interval from sampling to delivery, neonatal survival, neonatal birth weight, and histologic and clinical chorioamnionitis. Macrolide antibiotics were prescribed depending on the type of microorganism isolated from the AF, clinically suspected IAI, and the discretion of the attending clinician.

RESULTS

IAI was identified in 65.5% (57/87) of patients with CI, of whom 73.6% (42/57) were treated with macrolide antibiotics. Among the CI patients with IAI (n = 57), 40 underwent rescue cerclage and 17 were expectantly managed. The rates of SPTBs at < 28 and < 34 weeks were significantly lower and the latency period was significantly longer in the cerclage group than in the group that was managed expectantly. The median birth weight and neonatal survival rate were significantly higher in the cerclage group than in the group that was managed expectantly. However, the rates of histologic and clinical chorioamnionitis did not differ between the groups. Multivariable analyses revealed that rescue cerclage placement and administration of macrolide antibiotics were significantly associated with a decrease in SPTBs at < 28 and < 34 weeks, prolonged gestational latency, and increased likelihood of neonatal survival, after adjusting for possible confounding parameters; however, macrolide antibiotic administration did not reach statistical significance with respect to SPTB at < 34 weeks and neonatal survival (P = 0.076 and 0.063, respectively).

CONCLUSION

Rescue cerclage along with macrolide antibiotic treatment may positively impact pregnancy and neonatal outcomes in women with CI complicated by IAI, compared with expectant management. These findings suggest the benefit of cerclage placement even in patients with CI complicated by IAI.

***ECD*** maternal C-reactive protein as a predictor of neonatal sepsis

Systemic bacterial infection in the newborn has a significant impact on neonatal mortality and morbidity. Non-invasive prenatal markers of risk could be useful in the prediction and prevention of neonatal sepsis. We evaluated the association of maternal third-trimester serum level of C-Reactive Protein (CRP) with neonatal sepsis in a sample of infants in the JAKids pregnancy and birth cohort study. A population-based nested case-control design was used to identify cases and controls of neonatal sepsis from the subset of infants in the JAKids study whose mothers had serum archived in the early third trimester and who were admitted to newborn intensive care. Cases were 25 neonates with neonatal sepsis identified from hospital records. Controls were a random sample of 62 sepsis-free neonates matched to cases within three gestational age strata - ≤32 weeks, 33-36 weeks, and ≥37 weeks.Mothers of neonatal sepsis cases ≥37 weeks had significantly higher mean levels of maternal CRP protein than mothers of controls (11.0 mg/dL ± 3.0 vs. 8.7 mg/dL ± 5.9; p < .05). Differences in maternal CRP were not found in sepsis cases born ≤32 weeks (9.5 mg/dL ± 4.2 vs 5.8 mg/dL ± 4.0, p = .23) nor in sepsis cases born at 33-36 weeks (9.0 mg/dL ± 3.6 vs 11.9 mg/dL ± 7.8, p = .34). Maternal third-trimester C-reactive protein levels were elevated in mothers of term-born neonates with sepsis, but not in the mothers of preterm neonates with sepsis.

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.

Thymic stromal lymphopoietin participates in the host response to intra-amniotic inflammation leading to preterm labor and birth

The aim of this study was to establish the role of thymic stromal lymphopoietin (TSLP) in the intra-amniotic host response of women with spontaneous preterm labor (sPTL) and birth. Amniotic fluid and chorioamniotic membranes (CAM) were collected from women with sPTL who delivered at term (n = 30) or preterm without intra-amniotic inflammation (n = 34), with sterile intra-amniotic inflammation (SIAI, n = 27), or with intra-amniotic infection (IAI, n = 17). Amnion epithelial cells (AEC), Ureaplasma parvum, and Sneathia spp. were also utilized. The expression of TSLP, TSLPR, and IL-7Rα was evaluated in amniotic fluid or CAM by RT-qPCR and/or immunoassays. AEC co-cultured with Ureaplasma parvum or Sneathia spp. were evaluated for TSLP expression by immunofluorescence and/or RT-qPCR. Our data show that TSLP was elevated in amniotic fluid of women with SIAI or IAI and expressed by the CAM. TSLPR and IL-7Rα had detectable gene and protein expression in the CAM; yet, CRLF2 was specifically elevated with IAI. While TSLP localized to all layers of the CAM and increased with SIAI or IAI, TSLPR and IL-7Rα were minimal and became most apparent with IAI. Co-culture experiments indicated that Ureaplasma parvum and Sneathia spp. differentially upregulated TSLP expression in AEC. Together, these findings indicate that TSLP is a central component of the intra-amniotic host response during sPTL.

A single-cell atlas of murine reproductive tissues during preterm labor

Preterm birth, the leading cause of perinatal morbidity and mortality worldwide, frequently results from the syndrome of preterm labor. The best-established causal link to preterm labor is intra-amniotic infection, which involves premature activation of the parturition cascade in the reproductive tissues. Herein, we utilize single-cell RNA sequencing (scRNA-seq) to generate a single-cell atlas of the murine uterus, decidua, and cervix in a model of infection-induced preterm labor. We show that preterm labor affects the transcriptomic profiles of specific immune and non-immune cell subsets. Shared and tissue-specific gene expression signatures are identified among affected cells. Determination of intercellular communications implicates specific cell types in preterm labor-associated signaling pathways across tissues. In silico comparison of murine and human uterine cell-cell interactions reveals conserved signaling pathways implicated in labor. Thus, our scRNA-seq data provide insights into the preterm labor-driven cellular landscape and communications in reproductive tissues.

Pregnancy-induced leukocytosis: A case report

BACKGROUND

Pregnancy is a complex physiological process. Physiological leukocytosis occurs often and is mainly associated with increased neutrophil counts, especially in the third trimester of pregnancy. Non-congenital leukocytosis with white blood cell counts above 20 × 10⁹/L lasting 13 wk during pregnancy is rare and has been reported occasionally. Herein, we present a case of pregnancy-induced leukocytosis.

CASE SUMMARY

We present the case of a 33-year-old Chinese woman at 27 wk of gestation who had a leukocytosis complication. No abnormalities were detected in the examinations before pregnancy or in the first trimester. From the third trimester of pregnancy, the patient began to suffer from asymptomatic leukocytosis. We administered antibiotics to treat the patient; however, the complication persisted until the patient underwent a cesarean section after 40⁺³ wk of gestation. One day after the cesarean section, the patient’s neutrophil count returned to normal. After 2 years of follow-up, we found that the patient and baby were healthy.

CONCLUSION

Pregnancy-induced leukocytosis seems to be associated with immunoregulation and pregnancy termination may be the most effective treatment approach for pregnancies complicated with malignant leukocytosis.

Preterm labor with intact membranes: a simple noninvasive method to identify patients at risk for intra-amniotic infection and/or inflammation

OBJECTIVE

To develop a noninvasive scoring system to identify patients at high risk for intra-amniotic infection and/or inflammation, which would reduce the need for amniocentesis.

METHODS

This prospective cohort study comprised patients admitted with preterm labor and intact membranes (20-34 weeks of gestation) who underwent a transabdominal amniocentesis and for whom concentrations of quantitative cervical fetal fibronectin and of maternal serum C-reactive protein (CRP) were determined. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. Multivariate logistic regression analysis was performed to identify intra-amniotic infection/inflammtion with noninvasive parameters that had a significant relationship with univariate analysis. With four parameters identified by multivariate analysis, we generated a noninvasive risk scoring system.

RESULTS

Of the study population consisting of 138 singleton pregnant women, (1) the overall rate of intra-amniotic infection/inflammation was 28.3% (39/138); (2) four parameters were used to develop a noninvasive risk scoring system [i.e. cervical fetal fibronectin concentration (score 0-2), maternal serum CRP concentration (score 0-2), cervical dilatation (score 0-2), and gestational age at presentation (score 0-1)]; the total score ranges from 0 to 7; 3) the area under the curve of the risk score was 0.96 (95% confidence interval (CI), 0.92-0.99), significantly higher than that of each predictor in the identification of intra-amniotic infection/inflammation (p < .001, for all); 4) the risk score with a cutoff of 4 had a sensitivity of 94.9% (37/39), a specificity of 90.9% (90/99), a positive predictive value of 80.4% (37/46), a negative predictive value of 97.8% (90/92), a positive likelihood ratio of 10.4 (95% CI, 5.6-19.5), and a negative likelihood ratio of 0.06 (95% CI, 0.15-0.22) in the identification of intra-amniotic infection/inflammation.

CONCLUSIONS

(1) The combination of four parameters (concentrations of cervical fetal fibronectin and maternal serum CRP, cervical dilatation, and gestational age) was independently associated with intra-amniotic infection and/or inflammation; and (2) the risk scoring system comprised of the combination of 4 noninvasive parameters was sensitive and specific to identify the patients at risk for intra-amniotic infection and/or inflammation.

The association between preterm delivery and postpartum bleeding in otherwise uncomplicated pregnancies

Objective

The primary aim was to investigate whether preterm delivery was an independent risk factor for blood or blood products transfusion in the intrapartum or postpartum period, considered as a proxy for severe obstetric bleeding.

Material and Methods

Throughout a 9-month-period, 216 uncomplicated singleton deliveries were included in a cross-sectional study after exclusion of severe maternal and fetal morbidity, such as chorioamnionitis, and use of medications including tocolytics. Maternal and neonatal data were evaluated and compared across preterm (between 24 0/7-36 6/7 weeks’ gestation) and term (between 37 0/7-41 6/7 weeks’ gestation) deliveries. Primary and secondary outcomes were requirement for blood or blood products transfusion until discharge and change in hemoglobin value and hematocrit from baseline to postpartum hour 6, respectively. Logistic regression models were constructed to evaluate the effect of preterm delivery on the primary outcome.

Results

There were 90 (41.7%) preterm deliveries with an overall cesarean section rate of 77.8%. Preterm delivery was not an independent risk factor for the primary outcome, when route of delivery, maternal body-mass index, antenatal steroid administration, and baseline (admission) platelet and leukocyte counts were controlled for [adjusted risk ratio, 2.46; 95% confidence interval (CI), 0.69-8.77; p=0.16]. Subgroup analysis, including cesarean deliveries, revealed a similar result (adjusted risk ratio, 1.65; 95% CI, 0.42-6.48; p=0.47). Secondary outcomes, including decrease in mean or percent values of hemoglobin and hematocrit measurements, were also similar across preterm and term groups, both after vaginal and cesarean delivery (for all comparisons, p>0.05).

Conclusion

Preterm delivery is not independently associated with increased requirement for blood transfusions or decreased hemoglobin and hematocrit values following otherwise uncomplicated vaginal or cesarean delivery of singletons.

Preterm Labor and Preterm-PROM at a Lower Gestational Age Are Associated with a Longer Latency-to-Delivery Even in Patients with the Same Intensity of Intra-Amniotic Inflammation: "Carroll-Model" Revisited

A previous study by Carroll et al. demonstrated that the time from preterm-PROM to delivery was longer at a lower gestational age (GA) when the membranes rupture, although the presence or absence of intra-amniotic inflammation (IAI) was not examined in that study. However, patients with either preterm labor (PTL) or preterm-PROM at a lower GA had more frequent IAI, which was associated with a shorter amniocentesis-to-delivery (ATD) interval as compared with inflammation-free amniotic fluid (AF). Up to now, there is no information about whether PTL and preterm-PROM at a lower GA are associated with a shorter or longer latency to delivery in cases with the same intensity of IAI. The objective of the study is to examine this issue. AF MMP-8 was measured in 476 singleton early preterm-gestations (21.5 < GA at amniocentesis < 34 wks) with PTL (n = 253) and preterm-PROM (n = 223). Patients were divided into three groups according to GA at amniocentesis (i.e., group-1: <26 wks; group-2: 26−30 wks; group-3: 30−34 wks). IAI was defined as an elevated AF MMP-8 (≥23 ng/mL), and IAI was classified into either mild IAI (AF MMP-8: 23−350 ng/mL) or severe IAI (AF MMP-8 ≥ 350 ng/mL). ATD interval was examined according to GA at amniocentesis in the context of the same intensity of IAI (i.e., inflammation-free AF, mild IAI, and severe IAI) among pregnant women with either PTL or preterm-PROM. IAI was more frequent at a lower GA in cases with PTL (group-1 vs. group-2 vs. group-3; 59.5% vs. 47.4% vs. 25.1%; X2test, p = 0.000034 and linear by linear association [LBLA], p = 0.000008) and in those with preterm-PROM (group-1 vs. group-2 vs. group-3; 69.2% vs. 50.0% vs. 32.0%; X2test, p = 0.000104, and LBLA, p = 0.000019). Of note, cases without IAI at a lower GA had a longer ATD interval in both PTL (Spearman’s rank correlation test, γ = −0.360, p = 0.000003) and preterm-PROM (γ = −0.570, p = 0.000001) groups. Moreover, the lower the GA, the longer the ATD interval, even among patients with mild and severe IAI in both PTL (Spearman’s rank correlation test; mild IAI, γ = −0.290, p = 0.039; severe IAI, γ = −0.299, p = 0.048) and preterm-PROM (mild IAI, γ = −0.565, p = 0.000013; severe IAI, γ = −0.363, p = 0.015) groups. In conclusion, PTL and preterm-PROM at a lower GA are associated with a longer latency to delivery, even in patients with the same intensity of IAI. This finding suggests that a more intense IAI may be needed for spontaneous preterm birth at a lower GA.

Evaluation of Complete Blood Cell Count Parameters in the Diagnosis of Threatened Preterm Labor and Premature Rupture of Membranes

<b><i>Purpose:</i></b> The purpose of this study was to investigate a possible relationship between systemic inflammatory markers such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte monocyte ratio (LMR), threatened preterm labor (TPL), and preterm premature rupture of membranes (PPROM), using complete blood cell count (CBC) parameters. <b><i>Method:</i></b> The study was carried out prospectively with patients admitted to our university hospital due to preterm labor and at risk of PPROM. The cases were divided into three groups according to their pregnancy status. Group 1 consisted of 90 patients with PPROM between 24th and 36th gestational weeks; group 2, 115 patients diagnosed with TPL between 24th and 36th gestational weeks; group 3, 101 patients over 36 weeks of gestation (control) who were not in labor. In addition to the demographic data of the patients, CBC parameters (white blood cell (WBC), Hg, Hct, Plt, lymphocyte, monocyte, mean platelet volume, PLR, LMR, and NLR) and C-reactive protein (CRP) values were examined and compared in each of the three groups. <b><i>Results:</i></b> CRP and WBC values of group 1 (PPROM) were higher than group 2 (TPL) and group 3 (control) (<i>p</i> &#x3c; 0.05 for both). Pearson correlation between the gestational age and PLR and NLR values was significant (<i>r</i> and <i>p</i> values for PLR and NLR, respectively, <i>r</i> = −0.18, <i>p</i> &#x3c; 0.001; <i>r</i> = −0.23, <i>p</i> &#x3c; 0.001). However, there was no significant difference between the groups regarding PLR, NLR, LMR, platelet, monocytes, and lymphocyte counts. <b><i>Conclusions:</i></b> Only WBC was a valuable parameter in predicting preterm labor and PPROM. Although there was no significant difference between the groups in PLR and NLR, a negative correlation was found with gestational age at delivery. CRP value is still a helpful parameter in PPROM and TPL prediction.

Comparison of automated total nucleated cell counts vs manual cell counts in the amniotic fluid for the classification of disease status in healthy and diseased pigs

BACKGROUND

An increase in the total nucleated cell count (TNCC) of amniotic fluid can detect inflammation in the amniotic cavity. Traditionally, a manual count is employed, but the technique suffers from inaccuracy and is labor intensive. Automated cell counting could enhance precision and timeliness.

OBJECTIVES

We aimed to analyze the cell counts in the amniotic fluid of preterm pigs using an automated method and compared the results with manual cell counts. We also tested if increased TNCC is associated with an inflammatory group in a porcine model of chorioamnionitis.

METHODS

Amniotic fluids from 34 preterm pigs were analyzed blindly using two automatic settings of the ADVIA 2120i hematology analyzer (whole blood [WB] and cell poor [CP] settings) and manually by two observers using Neubauer chambers. Inter- and intra-variability were calculated. The correlation analysis of TNCC/μL in amniotic fluid was determined between the methods, including Deming and Bland-Altman analyses. Fischer's exact tests compared the known health status of the pigs to the outcomes of the automatic and manual TNCC.

RESULTS

Inter- and intra-observer variability of the manual TNCC were high, although the correlation of TNCC between (r = .95, P < .0001) and within observers (r = .98, P < .0001; r = .89, P < .0001) was good. Correlation between the manual and CP TNCC was moderate and significant (r = .50, P = .014). Manual and WB TNCC were not correlated. The CP (P = .003) and manual (P = .0001) analyses accurately classified the disease state of the pigs.

CONCLUSIONS

An acceptable correlation between automatic CP TNCC and manual counting was demonstrated. Both methods could accurately classify the disease state of the pigs.

The Inflammatory Milieu of Amniotic Fluid Increases with Chorio-Deciduitis Grade in Inflammation-Restricted to Choriodecidua, but Not Amnionitis, of Extra-Placental Membranes

No information exists about whether intra-amniotic inflammatory response increases with a chorio-deciduitis grade in the context of both inflammation-restricted to chorio-decidua and amnionitis of extra-placental membranes among spontaneous preterm births. The objective of current study is to examine this issue. A study population included 195 singleton pregnant women with chorio-deciduitis, and who spontaneously delivered at preterm (21.6~35.7 weeks) within 7 days of amniocentesis. We examined intra-amniotic inflammatory response according to the chorio-deciduitis grade in the context of inflammation restricted to chorio-decidua and amnionitis of extra-placental membranes. Intra-amniotic inflammatory response was measured by MMP-8 concentration (ng/mL) and WBC-count (cells/mm3) in amniotic-fluid (AF). Inflammation restricted to chorio-decidua and amnionitis were present in 47.7% (93/195) and 52.3% (102/195) of cases, respectively. Median AF MMP-8 concentration and WBC-count significantly increased with chorio-deciduitis grade in the context of inflammation restricted to chorio-decidua. However, there was no significant difference in median AF MMP-8 concentration and WBC-count between chorio-deciduitis grade-1 and grade-2 in the context of amnionitis. The inflammatory milieu of AF increases with chorio-deciduitis grade in inflammation-restricted to chorio-decidua, but not amnionitis, of extra-placental membranes. This finding suggests that a chorio-deciduitis grade may have little effect on the intensification of intra-amniotic inflammatory response in the context of amnionitis of extra-placental membranes.

Acute chorioamnionitis and intra-amniotic inflammation are more severe according to outside-in neutrophil migration within the same chorio-decidua

OBJECTIVE

No information exists about whether acute histologic chorioamnionitis (acute-HCA) is more advanced and severe, and intra-amniotic inflammation is more frequent and intense according to outside in neutrophil migration within the same chorio-decidua. The objective of current study is to examine this issue.

MATERIALS AND METHODS

We included 106 singleton preterm-births (gestational age at delivery: 20-34 weeks) due to either preterm-labor or preterm-PROM in the context of acute chorio-deciduitis. Study-population was divided into 3 groups according to outside-in neutrophil migration within chorio-decidua as follows: 1) group-1: 'inflammation restricted to the decidua' (n = 22); 2) group-2: 'inflammation restricted to the MT of chorion and the decidua' (n = 31); 3) group-3: 'inflammation in the CT of chorion' (n = 53). We examined the frequency of inflammation in each placental compartment beyond chorio-decidua (i.e., amnion, umbilical cord, and chorionic-plate), and total grade (1-8) of acute-HCA. Moreover, the frequency of intra-amniotic infection (defined as positive amniotic-fluid culture for aerobic and anaerobic bacteria and genital mycoplasmas) and intra-amniotic inflammation (defined as amniotic fluid WBC ≥ 19 cells/mm³), and an intra-amniotic inflammatory response gauged by amnioticfluid WBC count (cells/mm³) were examined in 50 amniotic fluid samples within 7 days of birth.

RESULTS

Amnionitis, funisitis and chorionic plate inflammation were more frequent (each for P < 0.01) and median total grade of acute-HCA was increased (P < 0.001) according to outside-in neutrophil migration within chorio-decidua (group-1vs.group-2vs.group-3). Moreover, intra-amniotic infection and inflammation were more frequent (each-for P < 0.05) and median amniotic-fluid WBC count was increased (P < 0.01) according-to outside-in neutrophil-migration within chorio-decidua (group-1 vs. group-2 vs. group-3).

CONCLUSION

Acute-HCA is more advanced and severe, and intra-amniotic inflammation is more frequent and intense according to outside in neutrophil migration within the same chorio-decidua. This finding suggests that what is now acute chorio-deciduitis should be subdivided.

Neutrophil to Lymphocyte Ratio in Maternal Blood: A Clue to Suspect Amnionitis

There is no information about whether maternal neutrophil to lymphocyte ratios (NLRs) progressively increase with respect to the progression of acute histologic chorioamnionitis (acute-HCA) and increased maternal NLR is a risk factor for amnionitis, known as advanced acute-HCA, in pregnant women at risk for spontaneous preterm birth (PTB). The objective of the current study is to examine this issue. The study population included 132 singleton PTB (<34 weeks) due to either preterm labor or preterm-PROM with both placental pathology and maternal CBC results within 48 h before delivery. We examined maternal NLRs according to the progression of acute-HCA in extra-placental membranes (EPM) (i.e., group-0, inflammation-free EPM; group-1, inflammation restricted to decidua; group-2, inflammation restricted to the membranous trophoblast of chorion and the decidua; group-3, inflammation in the connective tissue of chorion but not amnion; group-4, amnionitis). Maternal NLRs significantly and progressively increased with the progression of acute-HCA (Spearman’s rank correlation test, γ = 0.363, p = 0.000019). Moreover, the increased maternal NLR (≥7.75) (Odds-ratio 5.56, 95% confidence-interval 1.26-24.62, p < 0.05) was a significant independent risk factor for amnionitis even after the correction for potential confounders. In conclusion, maternal NLRs significantly and progressively increased according to the progression of acute-HCA and the increased maternal NLR (≥7.75) was an independent risk factor for amnionitis in spontaneous PTB. The evaluation of the performance of NLR should clearly require a prospective description of this parameter in a cohort of patients with either threatened PTL or preterm-PROM.

Fetal Growth Restriction and Subsequent Low Grade Fetal Inflammatory Response Are Associated with Early-Onset Neonatal Sepsis in the Context of Early Preterm Sterile Intrauterine Environment

There is no information about whether fetal growth restriction (FGR) is an independent risk factor for low-grade fetal inflammatory response (FIR), and which is more valuable for the prediction of early-onset neonatal sepsis (EONS) between low-grade FIR or fetal inflammatory response syndrome (FIRS) in the context of human early preterm sterile intrauterine environment. We examined FIR (umbilical cord plasma (UCP) CRP concentration at birth) according to the presence or absence of FGR (birth weight < 5th percentile for gestational age (GA)) and EONS in 81 singleton preterm births (GA at delivery: 24.5~33.5 weeks) within 72 h after amniocentesis and with sterile intrauterine environment. A sterile intrauterine environment was defined by the presence of both a sterile amniotic fluid (AF) (AF with both negative culture and MMP-8 < 23 ng/mL) and inflammation-free placenta. Median UCP CRP (ng/mL) was higher in cases with FGR than in those without FGR (63.2 vs. 34.5; p = 0.018), and FGR was an independent risk factor for low-grade FIR (UCP CRP ≥ 52.8 ng/mL) (OR 3.003, 95% CI 1.024-8.812, p = 0.045) after correction for confounders. Notably, low-grade FIR (positive likelihood-ratio (LR) and 95% CI, 2.3969 (1.4141-4.0625); negative-LR and 95% CI, 0.4802 (0.2591-0.8902)), but not FIRS (positive-LR and 95% CI, 2.1071 (0.7526-5.8993); negative-LR and 95% CI, 0.8510 (0.6497-1.1145)), was useful for the identification of EONS. In conclusion, FGR is an independent risk factor for low-grade FIR, and low-grade FIR, but not FIRS, has a value for the identification of EONS in the context of the early preterm sterile intrauterine environment.

The Relationship Among Intra-Amniotic Inflammatory Response, The Progression of Inflammation in Chorionic Plate and Early-Onset Neonatal Sepsis

Background: The chorionic plate (CP) has been denigrated by the well-known route of the extraplacental membranes from the decidua parietalis through the chorion to the amnion in the progression of ascending intrauterine infection among preterm births (PTBs). However, considering previous studies reporting the relationship among intra-amniotic inflammatory response (IAIR), the progression of inflammation in extraplacental membranes and early-onset neonatal sepsis (EONS), and the anatomic connection between extraplacental membranes and CP, there is a good chance that IAIR would be more likely and severe according to the progression of inflammation in CP, and this progression of inflammation in CP would be associated with a significant increase in EONS in neonates delivered due to either PTL or preterm-PROM. Unfortunately, there is no information about the relationship among IAIR, the progression of inflammation in CP, and EONS among spontaneous PTBs. The objective of the current study is to examine this issue. Method: The study population included 309 singleton pregnant women-delivered preterm neonates with the following conditions: (1) gestational age (GA) at delivery: 20.0~36.9 weeks; (2) spontaneous PTBs: PTL (151 cases) or preterm-PROM (158 cases); (3) available results of placental histologic examination; (4) without congenital anomaly; and (5) delivery within 60 h of amniocentesis. We examined IAIR, and the frequency of intra-amniotic inflammation (IAI) and EONS according to the progression of inflammation in CP [i.e., stage-0, inflammation-free CP; stage-1, inflammation restricted to subchorionic fibrin (SCF); stage-2, inflammation in connective tissue (CT) of CP but without chorionic vasculitis; and stage-3, chorionic vasculitis]. IAIR was determined by amniotic fluid (AF) matrix metalloproteinase-8 (MMP-8) concentration (ng/ml), and IAI was defined as an elevated AF MMP-8 concentration (≥23 ng/ml). EONS included either suspected or proven EONS. Results: (1) Each stage (stage-0 to stage-3) was present in 69.3% (214/309), 15.9% (49/309), 11.0% (34/309), and 3.9% (12/309) of the study population. (2) AF MMP-8 concentrations continuously elevated according to the progression of inflammation in CP [stage-0 vs. stage-1 vs. stage-2 vs. stage-3; median (ng/ml), range (ng/ml); 6.0 (0.3-4202.7) vs. 153.9 (0.3-6142.6) vs. 464.9 (5.8-3929.0) vs. 1,780.4 (35.1-5019.5); Kruskal-Wallis test, P < 0.001 and Spearman's rank-correlation test, P < 0.000001, r = 0.553]. (3) Moreover, the frequency of IAI and EONS gradually increased with the progression of inflammation in CP [stage-0 vs. stage-1 vs. stage-2 vs. stage-3; IAI, 30.5% (64/210) vs. 70.2% (33/47) vs. 96.7% (29/30) vs. 100% (12/12); EONS, 3.5% (7/200) vs. 25.5% (12/47) vs. 32.3% (10/31) vs. 40.0% (4/10); each for Pearson's chi-square test, P < 0.000001 and linear-by-linear association, P < 0.000001]. (4) Of note, multiple logistic regression analysis demonstrated that a more advanced stage in the progression of inflammation within CP was associated with a higher odds ratio (OR) for EONS [stage-1 vs. stage-2 vs. stage-3; OR, 7.215, 95% confidence-interval (CI) (2.177-23.908) vs. OR, 10.705, 95% CI (2.613-43.849) vs. OR, 27.189, 95% CI (2.557-289.124)] compared with stage-0 even after the adjustment for potential confounding variables. Conclusion: IAIR is more likely and severe according to the progression of inflammation in CP, and this progression of inflammation in CP is an independent risk factor for EONS in spontaneous PTBs. This finding suggests that CP may be another playground for the progression of ascending intrauterine infection in addition to extraplacental membranes, and the progression of inflammation in CP may be used for the prediction of EONS in spontaneous PTBs.

RNA Sequencing Reveals Diverse Functions of Amniotic Fluid Neutrophils and Monocytes/Macrophages in Intra-Amniotic Infection

Intra-amniotic infection, the invasion of microbes into the amniotic cavity resulting in inflammation, is a clinical condition that can lead to adverse pregnancy outcomes for the mother and fetus as well as severe long-term neonatal morbidities. Despite much research focused on the consequences of intra-amniotic infection, there remains little knowledge about the innate immune cells that respond to invading microbes. We performed RNA-seq of sorted amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection to determine the transcriptomic differences between these innate immune cells. Further, we sought to identify specific transcriptomic pathways that were significantly altered by the maternal or fetal origin of amniotic fluid neutrophils and monocytes/macrophages, the presence of a severe fetal inflammatory response, and pregnancy outcome (i.e., preterm or term delivery). We show that significant transcriptomic differences exist between amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection, indicating the distinct roles these cells play. The transcriptome of amniotic fluid immune cells varies based on their maternal or fetal origin, and the significant transcriptomic differences between fetal and maternal monocytes/macrophages imply that those of fetal origin exhibit impaired functions. Notably, transcriptomic changes in amniotic fluid monocytes/macrophages suggest that these immune cells collaborate with neutrophils in the trafficking of fetal leukocytes throughout the umbilical cord (i.e., funisitis). Finally, amniotic fluid neutrophils and monocytes/macrophages from preterm deliveries display enhanced transcriptional activity compared to those from term deliveries, highlighting the protective role of these cells during this vulnerable period. Collectively, these findings demonstrate the underlying complexity of local innate immune responses in women with intra-amniotic infection and provide new insights into the functions of neutrophils and monocytes/macrophages in the amniotic cavity.

FIRS: Neonatal considerations

Fetal Inflammatory Response Syndrome (FIRS) is the fetal counterpart of systemic inflammatory response syndrome (SIRS) described in adults. When the fetus is directly exposed to inflammation of the fetal membranes or the placental-fetal circulation, and organs are adversely affected, the disorder is known as FIRS. This syndrome can significantly affect multiple organs with significant short and long term implications for the newborn. In cases of neonatal encephalopathy when no obvious etiology is identified, FIRS needs to be considered. Based on the significant incidence of chorioamnionitis and its potential effects on the newborn, any evidence of maternal, fetal, or neonatal infection should mandate further evaluation of the placenta and membrane histopathology.

Intra-amniotic inflammation induces preterm birth by activating the NLRP3 inflammasome†

Intra-amniotic inflammation is strongly associated with spontaneous preterm labor and birth, the leading cause of perinatal mortality and morbidity worldwide. Previous studies have suggested a role for the NLRP3 (NLR family pyrin domain-containing protein 3) inflammasome in the mechanisms that lead to preterm labor and birth. However, a causal link between the NLRP3 inflammasome and preterm labor/birth induced by intra-amniotic inflammation has not been established. Herein, using an animal model of lipopolysaccharide-induced intra-amniotic inflammation (IAI), we demonstrated that there was priming of the NLRP3 inflammasome (1) at the transcriptional level, indicated by enhanced mRNA expression of inflammasome-related genes (Nlrp3, Casp1, Il1b); and (2) at the protein level, indicated by greater protein concentrations of NLRP3, in both the fetal membranes and decidua basalis prior to preterm birth. Additionally, we showed that there was canonical activation of the NLRP3 inflammasome in the fetal membranes, but not in the decidua basalis, prior to IAI-induced preterm birth as evidenced by increased protein levels of active caspase-1. Protein concentrations of released IL1β were also increased in both the fetal membranes and decidua basalis, as well as in the amniotic fluid, prior to IAI-induced preterm birth. Finally, using the specific NLRP3 inhibitor, MCC950, we showed that in vivo inhibition of the NLRP3 inflammasome reduced IAI-induced preterm birth and neonatal mortality. Collectively, these results provide a causal link between NLRP3 inflammasome activation and spontaneous preterm labor and birth in the context of intra-amniotic inflammation. We also showed that, by targeting the NLRP3 inflammasome, adverse pregnancy and neonatal outcomes can be significantly reduced.

Fetal inflammatory response is positively correlated with the progress of inflammation in chorionic plate

INTRODUCTION

No information exists about the relationship among the progress of inflammation in chorionic-plate, fetal inflammatory response (FIR), funisitis, amnionitis and early-onset neonatal sepsis (EONS) in patients with either preterm labor or preterm premature rupture of membranes (preterm-PROM). The objective of current study is to examine this issue.

METHODS

Study population included 247 singleton preterm gestations (21.6 weeks ≤ gestational age at delivery≤36 weeks) who had either preterm-labor or preterm-PROM with acute placental inflammation. We examined the intensity of FIR, and the frequency of fetal inflammatory response syndrome (FIRS), funisitis, amnionitis and proven or suspected EONS according to the progress of inflammation in chorionic-plate. The intensity of FIR was measured with umbilical cord plasma (UCP)-CRP concentration (ng/ml) at birth, and FIRS was defined as an elevated UCP-CRP concentration (≥200 ng/ml). The progress of inflammation in chorionic-plate was divided with a slight modification from previously reported-criteria as follows: stage-0, inflammation-free chorionic-plate; stage-1, inflammation restricted to subchorionic fibrin (SCF); stage-2, inflammation in the connective tissue (CT) of chorionic-plate without chorionic vasculitis; stage-3, chorionic vasculitis.

RESULTS

1) Stage-0, stage-1, stage-2 and stage-3 of inflammation in chorionic-plate were present in 36.8% (91/247), 29.6% (73/247), 25.5% (63/247), and 8.1% (20/247) of cases; 2) UCP-CRP concentration at birth was significantly and positively correlated with the progress of inflammation in chorionic-plate (Spearman's rank correlation test, P < .000001, γ = 0.391 and Kruskal-Wallis test, P < .001); 3) Moreover, FIRS, funisitis, amnionitis, and EONS were significantly more frequent as a function of the progress of inflammation in chorionic-plate.

DISCUSSION

The intensity of FIR and the frequency of FIRS were positively correlated with the progress of inflammation in chorionic-plate in patients with either PTL or preterm-PROM. This suggests chorionic-plate may be an independent compartment for the analysis of inflammation.

Inflammasomes: Their Role in Normal and Complicated Pregnancies

Inflammasomes are cytoplasmic multiprotein complexes that coordinate inflammatory responses, including those that take place during pregnancy. Inflammasomes and their downstream mediators caspase-1 and IL-1β are expressed by gestational tissues (e.g., the placenta and chorioamniotic membranes) during normal pregnancy. Yet, only the activation of the NLRP3 inflammasome in the chorioamniotic membranes has been partially implicated in the sterile inflammatory process of term parturition. In vivo and ex vivo studies have consistently shown that the activation of the NLRP3 inflammasome is a mechanism whereby preterm labor and birth occur in the context of microbial- or alarmin-induced inflammation. In the placenta, the activation of the NLRP3 inflammasome is involved in the pathogenesis of preeclampsia and other pregnancy syndromes associated with placental inflammation. This evidence suggests that inhibition of the NLRP3 inflammasome or its downstream mediators may foster the development of novel anti-inflammatory therapies for the prevention or treatment of pregnancy complications.

The relationship among the progression of inflammation in umbilical cord, fetal inflammatory response, early-onset neonatal sepsis, and chorioamnionitis

OBJECTIVES

No information exists about whether fetal inflammatory-response(FIR), early-onset neonatal sepsis(EONS) and chorioamnionitis(an advanced-stage of maternal inflammatory-response in extraplacental membranes) continuously increase according to the progression of inflammation in umbilical-cord(UC). The objective of current-study is to examine this-issue.

METHODS

Study-population included 239singleton pregnant-women(gestational-age[GA] at delivery: 21.6~36weeks) who had inflammation in extraplacental membranes or chorionic plate (CP) and either preterm-labor or preterm-PROM. We examined FIR, and the frequency of fetal inflammatory-responses syndrome(FIRS), proven-EONS, suspected-EONS and chorioamnionitis according to the progression of inflammation in UC. The progression of inflammation in UC was divided with a slight-modification from previously reported-criteria as follows: stage0, inflammation-free UC; stage-1: umbilical phlebitis only; stage-2: involvement of at least one UA and either the other UA or UV without extension into WJ; stage-3: the extension of inflammation into WJ. FIR was gauged by umbilical-cord-plasma(UCP) CRP concentration(ng/ml) at birth, and FIRS was defined as an elevated UCP CRP concentration at birth(≥200ng/ml).

RESULTS

Stage-0, stage-1, stage-2 and stage-3 of inflammation in UC were present in 48.1%, 15.5%, 6.7%, and 29.7% of cases. FIR continuously increased according to the progression of inflammation in UC(Kruskal-Wallis test,P<0.001; Spearman-rank-correlation test,P<0.000001,r = 0.546). Moreover, there was a significant and stepwise increase in the frequency of FIRS, proven-EONS, suspected-EONS and chorioamnionitis according to the progression of inflammation in UC(each for P<0.000005 in both chi-square test and linear-by-linear-association). Multiple logistic-regression analysis demonstrated that the more advanced-stage in the progression of inflammation in UC(i.e., stage-1 vs. stage-2 vs. stage-3), the better predictor of suspected-EONS (Odds-ratio[OR]3.358, 95%confidence-interval[CI]:1.020-11.057 vs. OR5.147, 95%CI:1.189-22.275 vs. OR11.040, 95%CI:4.118-29.592) and chorioamnionitis(OR6.593, 95%CI:2.717-15.999 vs. OR16.508, 95%CI:3.916-69.596 vs. OR20.167, 95%CI:8.629-47.137).

CONCLUSION

FIR, EONS and chorioamnionitis continuously increase according to the progression of inflammation in UC among preterm-gestations with inflammation in extraplacental membranes or CP. This finding may suggest that funisitis(inflammation in UC) is both qualitatively and quantitatively histologic-counterpart of FIRS, and a surrogate-marker for chorioamnionitis.

The origin of amniotic fluid monocytes/macrophages in women with intra-amniotic inflammation or infection

Background Monocytes, after neutrophils, are the most abundant white blood cells found in the amniotic cavity of women with intra-amniotic inflammation/infection. However, the origin of such cells has not been fully investigated. Herein, we determined (1) the origin of amniotic fluid monocytes/macrophages from women with intra-amniotic inflammation/infection, (2) the relationship between the origin of amniotic fluid monocytes/macrophages and preterm or term delivery and (3) the localization of monocytes/macrophages in the placental tissues. Methods Amniotic fluid samples (n = 16) were collected from women with suspected intra-amniotic inflammation or infection. Amniotic fluid monocytes/macrophages were purified by fluorescence-activated cell sorting, and DNA fingerprinting was performed. Blinded placental histopathological evaluations were conducted. Immunohistochemistry was performed to detect CD14+ monocytes/macrophages in the placental tissues. Results DNA fingerprinting revealed that (1) 56.25% (9/16) of amniotic fluid samples had mostly fetal monocytes/macrophages, (2) 37.5% (6/16) had predominantly maternal monocytes/macrophages and (3) one sample (6.25% [1/16]) had a mixture of fetal and maternal monocytes/macrophages. (4) Most samples with predominantly fetal monocytes/macrophages were from women who delivered early preterm neonates (77.8% [7/9]), whereas all samples with mostly maternal monocytes/macrophages or a mixture of both were from women who delivered term or late preterm neonates (100% [7/7]). (5) Most of the women included in this study presented acute maternal and fetal inflammatory responses in the placenta (85.7% [12/14]). (6) Women who had mostly fetal monocytes/macrophages in amniotic fluid had abundant CD14+ cells in the umbilical cord and chorionic plate, whereas women with mostly maternal amniotic fluid monocytes/macrophages had abundant CD14+ cells in the chorioamniotic membranes. Conclusion Amniotic fluid monocytes/macrophages can be of either fetal or maternal origin, or a mixture of both, in women with intra-amniotic inflammation or infection. These immune cells could be derived from the fetal and maternal vasculature of the placenta.

Antibiotic administration can eradicate intra-amniotic infection or intra-amniotic inflammation in a subset of patients with preterm labor and intact membranes

BACKGROUND

Intra-amniotic infection is present in 10% of patients with an episode of preterm labor, and is a risk factor for impending preterm delivery and neonatal morbidity/mortality. Intra-amniotic inflammation is often associated with intra-amniotic infection, but is sometimes present in the absence of detectable microorganisms. Antibiotic treatment of intra-amniotic infection has traditionally been considered to be ineffective. Intra-amniotic inflammation without microorganisms has a prognosis similar to that of intra-amniotic infection.

OBJECTIVE

To determine whether antibiotics can eradicate intra-amniotic infection or intra-amniotic inflammation in a subset of patients with preterm labor and intact membranes.

MATERIALS AND METHODS

The study population consisted of women who met the following criteria: 1) singleton gestation between 20 and 34 weeks; 2) preterm labor and intact membranes; 3) transabdominal amniocentesis performed for the evaluation of the microbiologic/inflammatory status of the amniotic cavity; 4) intra-amniotic infection and/or intra-amniotic inflammation; and 5) received antibiotic treatment that consisted of ceftriaxone, clarithromycin, and metronidazole. Follow-up amniocentesis was performed in a subset of patients. Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction was performed for Ureaplasma spp. Intra-amniotic infection was defined as a positive amniotic fluid culture or positive polymerase chain reaction, and intra-amniotic inflammation was suspected when there was an elevated amniotic fluid white blood cell count or a positive result of a rapid test for matrix metalloproteinase-8. For this study, the final diagnosis of intra-amniotic inflammation was made by measuring the interleukin-6 concentration in stored amniotic fluid (>2.6 ng/mL). These results were not available to managing clinicians. Treatment success was defined as eradication of intra-amniotic infection and/or intra-amniotic inflammation or delivery ≥37 weeks.

RESULTS

Of 62 patients with intra-amniotic infection and/or intra-amniotic inflammation, 50 received the antibiotic regimen. Of those patients, 29 were undelivered for ≥7 days and 19 underwent a follow-up amniocentesis. Microorganisms were identified by culture or polymerase chain reaction of amniotic fluid obtained at admission in 21% of patients (4/19) who had a follow-up amniocentesis, and were eradicated in 3 of the 4 patients. Resolution of intra-amniotic infection/inflammation was confirmed in 79% of patients (15/19), and 1 other patient delivered at term, although resolution of intra-amniotic inflammation could not be confirmed after a follow-up amniocentesis. Thus, resolution of intra-amniotic inflammation/infection or term delivery (treatment success) occurred in 84% of patients (16/19) who had a follow-up amniocentesis. Treatment success occurred in 32% of patients (16/50) with intra-amniotic infection/inflammation who received antibiotics. The median amniocentesis-to-delivery interval was significantly longer among women who received the combination of antibiotics than among those who did not (11.4 days vs 3.1 days: P = .04).

CONCLUSION

Eradication of intra-amniotic infection/inflammation after treatment with antibiotics was confirmed in 79% of patients with preterm labor, intact membranes, and intra-amniotic infection/inflammation who had a follow-up amniocentesis. Treatment success occurred in 84% of patients who underwent a follow-up amniocentesis and in 32% of women who received the antibiotic regimen.

A high concentration of fetal fibronectin in cervical secretions increases the risk of intra-amniotic infection and inflammation in patients with preterm labor and intact membranes

Objective To determine whether the risk of intra-amniotic infection/inflammation and spontaneous preterm delivery (SPTD) varies as a function of the concentration of cervical fetal fibronectin (fFN) in patients with preterm labor and intact membranes. Methods This prospective study included 180 patients with preterm labor and intact membranes who had a sample collected for quantitative fFN measurement and underwent amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas. Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. Results (1) The prevalence of intra-amniotic infection/inflammation and SPTD within 7 days was 32.2% (58/180) and 33.9% (61/178), respectively; (2) The higher the fFN concentration, the greater the risk of intra-amniotic infection/inflammation and SPTD within 7 days (P<0.001, respectively); (3) An fFN concentration 150 ng/mL had a better diagnostic performance than an fFN 50 ng/mL in the identification of intra-amniotic infection/inflammation and SPTD within 7 days; (4) Among the patients with an fFN <50 ng/mL, intra-amniotic infection/inflammation was identified in 7.6% (6/79) of patients and 66.7% (4/6) delivered within 7 days. Conclusion The higher the concentration of fFN, the greater the risk of intra-amniotic infection/inflammation and SPTD in patients with preterm labor and intact membranes.

The frequency and clinical significance of intra-amniotic inflammation in twin pregnancies with preterm labor and intact membranes

OBJECTIVE

The objective of this study is to evaluate the frequency and clinical significance of intra-amniotic inflammation in twin pregnancies with preterm labor and intact membranes.

STUDY DESIGN

Amniotic fluid (AF) was retrieved from both sacs in 90 twin gestations with preterm labor and intact membranes (gestational age between 20 and 34 6/7 weeks). Preterm labor was defined as the presence of painful regular uterine contractions, with a frequency of at least 2 every 10 min, requiring hospitalization. Fluid was cultured and assayed for matrix metalloproteinase-8. Intra-amniotic inflammation was defined as an AF matrix metalloproteinase-8 concentration >23 ng/mL.

RESULTS

The prevalence of intra-amniotic inflammation for at least 1 amniotic sac was 39% (35/90), while that of proven intra-amniotic infection for at least one amniotic sac was 10% (9/90). Intra-amniotic inflammation without proven microbial invasion of the amniotic cavity was found in 29% (26/90) of the cases. Intra-amniotic inflammation was present in both amniotic sacs for 22 cases, in the presenting amniotic sac for 12 cases, and in the non-presenting amniotic sac for one case. Women with intra-amniotic inflammation observed in at least one amniotic sac and a negative AF culture for microorganisms had a significantly higher rate of adverse pregnancy outcome than those with a negative AF culture and without intra-amniotic inflammation (lower gestational age at birth, shorter amniocentesis-to-delivery interval, and significant neonatal morbidity). Importantly, there was no significant difference in pregnancy outcome between women with intra-amniotic inflammation and a negative AF culture and those with a positive AF culture.

CONCLUSION

Intra-amniotic inflammation is present in 39% of twin pregnancies with preterm labor and intact membranes and is a risk factor for impending preterm delivery and adverse outcome, regardless of the presence or absence of bacteria detected using cultivation techniques.

Inflammation-Induced Adverse Pregnancy and Neonatal Outcomes Can Be Improved by the Immunomodulatory Peptide Exendin-4

Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. Inflammation is causally linked to preterm birth; therefore, finding an intervention that dampens maternal and fetal inflammatory responses may provide a new strategy to prevent adverse pregnancy and neonatal outcomes. Using animal models of systemic maternal inflammation [intraperitoneal injection of lipopolysaccharide (LPS)] and fetal inflammation (intra-amniotic administration of LPS), we found that (1) systemic inflammation induced adverse pregnancy and neonatal outcomes by causing a severe maternal cytokine storm and a mild fetal cytokine response; (2) fetal inflammation induced adverse pregnancy and neonatal outcomes by causing a mild maternal cytokine response and a severe fetal cytokine storm; (3) exendin-4 (Ex4) treatment of dams with systemic inflammation or fetal inflammation improved adverse pregnancy outcomes by modestly reducing the rate of preterm birth; (4) Ex4 treatment of dams with systemic, but not local, inflammation considerably improved neonatal outcomes, and such neonates continued to thrive; (5) systemic inflammation facilitated the diffusion of Ex4 through the uterus and the maternal-fetal interface; (6) neonates born to Ex4-treated dams with systemic inflammation displayed a similar cytokine profile to healthy control neonates; and (7) treatment with Ex4 had immunomodulatory effects by inducing an M2 macrophage polarization and increasing anti-inflammatory neutrophils, as well as suppressing the expansion of CD8+ regulatory T cells, in neonates born to dams with systemic inflammation. Collectively, these results provide evidence that dampening maternal systemic inflammation through novel interventions, such as Ex4, can improve the quality of life for neonates born to women with this clinical condition.

Plasma inflammatory and immune proteins as predictors of intra-amniotic infection and spontaneous preterm delivery in women with preterm labor: a retrospective study

Background

We investigated whether various inflammatory and immune proteins in plasma predict intra-amniotic infection and imminent preterm delivery in women with preterm labor and compared their predictive ability with that of amniotic fluid (AF) interleukin (IL)-6 and serum C-reactive protein (CRP).

Methods

This retrospective cohort study included 173 consecutive women with preterm labor who underwent amniocentesis for diagnosis of infection and/or inflammation in the AF. The AF was cultured, and assayed for IL-6. CRP levels and cervical length by transvaginal ultrasound were measured at the time of amniocentesis. The stored maternal plasma was assayed for IL-6, matrix metalloproteinase (MMP)-9, and complements C3a and C5a using ELISA kits. The primary and secondary outcome criteria were positive AF cultures and spontaneous preterm delivery (SPTD) within 48 h, respectively. Univariate, multivariate, and receiver operating characteristic analysis were used for the statistical analysis.

Results

In bivariate analyses, elevated plasma IL-6 level was significantly associated with intra-amniotic infection and imminent preterm delivery, whereas elevated plasma levels of MMP-9, C3a, and C5a were not associated with these two outcomes. On multivariate analyses, an elevated plasma IL-6 level was significantly associated with intra-amniotic infection and imminent preterm delivery after adjusting for confounders, including high serum CRP levels and short cervical length. In predicting intra-amniotic infection, the area under the curve (AUC) was significantly lower for plasma IL-6 than for AF IL-6 but was similar to that for serum CRP. Differences in the AUCs between plasma IL-6, AF IL-6, and serum CRP were not statistically significant in predicting imminent preterm delivery.

Conclusions

Maternal plasma IL-6 independently predicts intra-amniotic infection in women with preterm labor; however, it has worse diagnostic performance than that of AF IL-6 and similar performance to that of serum CRP. To predict imminent preterm delivery, plasma IL-6 had an overall diagnostic performance similar to that of AF IL-6 and serum CRP. Plasma MMP-9, C3a, and C5a levels could not predict intra-amniotic infection or imminent preterm delivery.

The immunophenotype of amniotic fluid leukocytes in normal and complicated pregnancies

PROBLEM

The immune cellular composition of amniotic fluid is poorly understood. Herein, we determined: 1) the immunophenotype of amniotic fluid immune cells during the second and third trimester in the absence of intra-amniotic infection/inflammation; 2) whether amniotic fluid T cells and ILCs display different phenotypical characteristics to that of peripheral cells; and 3) whether the amniotic fluid immune cells are altered in women with intra-amniotic infection/inflammation.

METHOD OF STUDY

Amniotic fluid samples (n = 57) were collected from 15 to 40 weeks of gestation in women without intra-amniotic infection/inflammation. Samples from women with intra-amniotic infection/inflammation were also included (n = 9). Peripheral blood mononuclear cells from healthy adults were used as controls (n = 3). Immunophenotyping was performed using flow cytometry.

RESULTS

In the absence of intra-amniotic infection/inflammation, the amniotic fluid contained several immune cell populations between 15 and 40 weeks. Among these immune cells: (i) T cells and ILCs were greater than B cells and natural killer (NK) cells between 15 and 30 weeks; (ii) T cells were most abundant between 15 and 30 weeks; (iii) ILCs were most abundant between 15 and 20 weeks; (iv) B cells were scarce between 15 and 20 weeks; yet, they increased and were constant after 20 weeks; (v) NK cells were greater between 15 and 30 weeks than at term; (vi) ILCs expressed high levels of RORγt, CD161, and CD103 (ie, group 3 ILCs); (vii) T cells expressed high levels of RORγt; (viii) neutrophils increased as gestation progressed; and (ix) monocytes/macrophages emerged after 20 weeks and remained constant until term. All of the amniotic fluid immune cells, except ILCs, were increased in the presence of intra-amniotic infection/inflammation.

CONCLUSION

The amniotic fluid harbors a diverse immune cellular composition during normal and complicated pregnancies.

Identification of preterm birth in women with threatened preterm labour between 34 and 37 weeks of gestation

The aim of this study was to assess whether serum markers would be useful as a new predictor of preterm birth in patients with spontaneous, late preterm labour. Patients diagnosed with late preterm labour were divided into preterm delivery (229 patients) and term delivery (178 patients) groups. The two groups were compared in terms of clinical characteristics and levels of serum markers (leukocyte subtypes, platelet, C-reactive protein [CRP], neutrophil to lymphocyte ratio [NLR] and platelet to lymphocyte ratio [PLR]), which were obtained at admission. The levels of leukocyte (p < .001), neutrophil (p < .001), CRP (p = .001), NLR (p < .001) and PLR (p = .003) were significantly higher, whereas lymphocytes (p = .012) were significantly lower in the preterm delivery group, compared to the term delivery group. On multivariate regression analysis, NLR positive was the most powerful predictive variable (OR = 1.41; 95%CI: 1.32-1.51; p = .005). NLR had the highest area under curve (0.711; 95%CI 0.662-0.760) in predicting preterm birth and a NLR >6.2 had the highest sensitivity (65.1%) and specificity (62.5%). High NLR at admission is an independent predictor of preterm birth in patients with spontaneous, late preterm labour. Impact statement What is already known on this subject: Preterm birth accounts for 5-12% of all births, and is a major factor associated with perinatal morbidity and mortality worldwide. However, more than 70% of preterm births occur at late preterm between 34^0/7 and 36^6/7 weeks of gestation. The central role of systemic and subclinical infections in preterm labour is well documented. Intrauterine infection leading to delivery can be measured by using a variety of laboratory parameters. What do the results of this study add: Neutrophil to lymphocyte ratio is an inexpensive, easily interpretable and promising haematologic parameter that is widely available. This study explored the association of high neutrophil to lymphocyte ratio with the risk of preterm birth in women with preterm labour between 34 and 37 weeks of gestation. What are the implications of these findings for clinical practice and/or further research: Neutrophil to lymphocyte ratio could be used in combination with existing markers to improve detection rates of preterm birth. Concomitant use of markers could be more powerful than measuring any of the individual markers alone.

The combined exposure to intra-amniotic inflammation and neonatal respiratory distress syndrome increases the risk of intraventricular hemorrhage in preterm neonates

OBJECTIVE

To evaluate the impact of combined exposure to intra-amniotic inflammation and neonatal respiratory distress syndrome (RDS) on the development of intraventricular hemorrhage (IVH) in preterm neonates.

METHODS

This retrospective cohort study includes 207 consecutive preterm births (24.0-33.0 weeks of gestation). Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. According to McMenamin's classification, IVH was defined as grade II or higher when detected by neurosonography within the first weeks of life.

RESULTS

(1) IVH was diagnosed in 6.8% (14/207) of neonates in the study population; (2) IVH was frequent among newborns exposed to intra-amniotic inflammation when followed by postnatal RDS [33% (6/18)]. The frequency of IVH was 7% (8/115) among neonates exposed to either of these conditions - intra-amniotic inflammation or RDS - and 0% (0/64) among those who were not exposed to these conditions; and (3) Neonates exposed to intra-amniotic inflammation and postnatal RDS had a significantly higher risk of IVH than those with only intra-amniotic inflammation [odds ratio (OR) 4.6, 95% confidence interval (CI) 1.1-19.3] and those with RDS alone (OR 5.6, 95% CI 1.0-30.9), after adjusting for gestational age.

CONCLUSION

The combined exposure to intra-amniotic inflammation and postnatal RDS markedly increased the risk of IVH in preterm neonates.

Are amniotic fluid neutrophils in women with intraamniotic infection and/or inflammation of fetal or maternal origin?

BACKGROUND

Neutrophils are the most abundant white blood cells found in the amniotic cavity of women with intraamniotic infection and/or inflammation. The current belief is that these neutrophils are of fetal origin. However, abundant neutrophils have been found in the amniotic fluid of women with a severe acute maternal inflammatory response but without a severe fetal inflammatory response in the placenta, suggesting that these innate immune cells can also be of maternal origin or a mixture of both fetal and maternal neutrophils.

OBJECTIVE

We sought to investigate the origin of amniotic fluid neutrophils from women with intraamniotic infection and/or inflammation and to correlate these findings with acute histologic maternal and fetal inflammatory responses in the placenta.

STUDY DESIGN

Amniotic fluid was collected from 15 women with suspected intraamniotic infection and/or inflammation (positive microbiological cultures and/or interleukin-6 concentrations ≥2.6 ng/mL). Amniotic fluid neutrophils were purified by fluorescence-activated cell sorting, DNA was extracted, and DNA fingerprinting was performed. DNA fingerprinting was also performed in the umbilical cord and maternal blood DNA. Fluorescence in situ hybridization was assayed in women with male neonates. Blinded placental histopathological evaluations were conducted.

RESULTS

First, DNA fingerprinting revealed that 43% (6/14) of women who underwent a single amniocentesis had mostly fetal neutrophils in the amniotic fluid. Second, DNA fingerprinting showed that 36% (5/14) of the women who underwent a single amniocentesis had predominantly maternal neutrophils in the amniotic fluid. Third, DNA fingerprinting indicated that 21% (3/14) of the women who underwent a single amniocentesis had an evident mixture of fetal and maternal neutrophils in the amniotic fluid. Fourth, DNA fingerprinting revealed that a woman who underwent 2 amniocenteses (patient 15) had fetal neutrophils first, and as infection progressed, abundant maternal neutrophils invaded the amniotic cavity. Fifth, fluorescence in situ hybridization confirmed DNA fingerprinting results by showing that both fetal and maternal neutrophils were present in the amniotic fluid. Sixth, most of the women who had predominantly amniotic fluid neutrophils of fetal origin at the time of collection delivered extremely preterm neonates (71% [5/7]). Seventh, all of the women who had predominantly amniotic fluid neutrophils of maternal origin at the time of collection delivered term or late preterm neonates (100% [6/6]). Eighth, 2 of the women who had an evident mixture of fetal and maternal neutrophils in the amniotic fluid at the time of collection delivered extremely preterm neonates (67% [2/3]), and the third woman delivered a term neonate (33% [1/3]). Finally, most of the women included in this study presented acute maternal and fetal inflammatory responses in the placenta (87% [13/15]).

CONCLUSION

Amniotic fluid neutrophils can be either predominantly of fetal or maternal origin, or a mixture of both fetal and maternal origin, in women with intraamniotic infection and/or inflammation. The findings herein provide evidence that both fetal and maternal neutrophils can invade the amniotic cavity, suggesting that both the fetus and the mother participate in the host defense mechanisms against intraamniotic infection.

Amniotic fluid neutrophils can phagocytize bacteria: A mechanism for microbial killing in the amniotic cavity

PROBLEM

Neutrophils are capable of performing phagocytosis, a primary mechanism for microbial killing. Intra-amniotic infection is characterized by an influx of neutrophils into the amniotic cavity. Herein, we investigated whether amniotic fluid neutrophils could phagocytize bacteria found in the amniotic cavity of women with intra-amniotic infection.

METHODS

Amniotic fluid neutrophils from women with intra-amniotic infection were visualized by transmission electron microscopy (n=6). The phagocytic activity of amniotic fluid neutrophils from women with intra-amniotic infection and/or inflammation (n=10) or peripheral neutrophils from healthy individuals (controls, n=3) was tested using ex vivo phagocytosis assays coupled with live imaging. Phagocytosis by amniotic fluid neutrophils was also visualized by confocal microscopy (n=10) as well as scanning and transmission electron microscopy (n=5).

RESULTS

(i) Intra-amniotic infection-related bacteria including cocci (eg Streptococcus agalactiae), bacilli (eg Bacteriodes fragilis and Prevotella spp.), and small bacteria without a cell wall (eg Ureaplasma urealyticum) were found inside of amniotic fluid neutrophils; (ii) peripheral neutrophils (controls) rapidly phagocytized S. agalactiae, U. urealyticum, Gardnerella vaginalis, and Escherichia coli; (iii) amniotic fluid neutrophils rapidly phagocytized S. agalactiae and G. vaginalis; and (iv) amniotic fluid neutrophils slowly phagocytized U. urealyticum and E. coli; yet, the process of phagocytosis of the genital mycoplasma was lengthier.

CONCLUSION

Amniotic fluid neutrophils can phagocytize bacteria found in the amniotic cavity of women with intra-amniotic infection, namely S. agalactiae, U. urealyticum, G. vaginalis, and E. coli. Yet, differences in the rapidity of phagocytosis were observed among the studied microorganisms. These findings provide a host defense mechanism whereby amniotic fluid neutrophils can kill microbes invading the amniotic cavity.

Neutrophil Extracellular Traps in the Amniotic Cavity of Women with Intra-Amniotic Infection: A New Mechanism of Host Defense

OBJECTIVE

Neutrophil extracellular traps (NETs) control microbial infections through their antimicrobial activities attributed to DNA, histones, granules, and cytoplasmic proteins (eg, elastase). Intra-amniotic infection is characterized by the influx of neutrophils into the amniotic cavity; therefore, the aim of this study was to determine whether amniotic fluid neutrophils form NETs in this inflammatory process.

METHODS

Amniotic fluid samples from women with intra-amniotic infection (n = 15) were stained for bacteria detection using fluorescent dyes. Amniotic fluid neutrophils were purified by filtration. As controls, neutrophils from maternal blood samples (n = 3) were isolated by density gradients. Isolated neutrophils were plated onto glass cover slips for culture with and without 100 nM of phorbol-12-myristate-13-acetate (PMA). NET formation was assessed by 4',6-diamidino-2-phenylindole (DAPI) staining and scanning electron microscopy. Different stages of NET formation were visualized using antibodies against elastase and histone H3, in combination with DAPI staining, by confocal microscopy. Finally, maternal or neonatal neutrophils were added to amniotic fluid samples from women without intra-amniotic infection (n = 4), and NET formation was evaluated by DAPI staining.

RESULTS

(1) NETs were present in the amniotic fluid of women with intra-amniotic infection; (2) all of the amniotic fluid samples had detectable live and dead bacteria associated with the presence of NETs; (3) in contrast to neutrophils from the maternal circulation, amniotic fluid neutrophils did not require PMA stimulation to form NETs; (4) different stages of NET formation were observed by co-localizing elastase, histone H3, and DNA in amniotic fluid neutrophils; and (5) neither maternal nor neonatal neutrophils form NETs in the amniotic fluid of women without intra-amniotic infection.

CONCLUSION

NETs are detectable in the amniotic fluid of women with intra-amniotic infection.

Clinical chorioamnionitis at term VII: the amniotic fluid cellular immune response

OBJECTIVES

1) To characterize the cellular composition of the amniotic fluid of patients diagnosed with clinical chorioamnionitis at term, as a function of the presence or absence of microorganisms determined by cultivation techniques, and 2) to characterize the cytokine production by white blood cells present in the amniotic fluid using flow cytometry-based techniques.

MATERIALS AND METHODS

Amniotic fluid samples from 20 women who had the diagnosis of clinical chorioamnionitis at term were analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital Mycoplasmas). Amniotic fluid IL-6 concentrations were determined by an enzyme-linked immunosorbent assay. Amniotic fluid leukocytes were visualized by using hematoxylin and eosin staining and immunofluorescence. Immunophenotyping of surface markers and cytokines was performed in amniotic fluid leukocytes using flow cytometry.

RESULTS

1) Neutrophils (CD45+CD15+ cells) were the most common leukocyte subset found in the amniotic fluid, followed by monocytes (CD45+CD14+ cells); other white blood cells (such as lymphocytes and natural killer cells) were scarce in the amniotic fluid; 2) the absolute counts of neutrophils and monocytes were significantly higher in patients with microorganisms found in the amniotic fluid than in those without detectable microorganisms, using cultivation techniques; 3) there was a significant correlation between the absolute counts of neutrophils and monocytes determined by flow cytometry (Spearman's correlation=0.97; P<0.001); 4) there was a significant correlation between the absolute white blood cell count determined with a hemocytometer chamber and by flow cytometric analysis (Spearman's correlation=0.88; P<0.001); and 5) the profile of cytokine expression differed between monocytes and neutrophils; while neutrophils predominantly produced TNF-α and MIP-1β, monocytes expressed higher levels of IL-1β and IL-1α.

CONCLUSION

Flow cytometry analysis of the amniotic fluid of patients with intra-amniotic infection and clinical chorioamnionitis at term demonstrated that neutrophils and monocytes are the most common cells participating in the inflammatory process. We have characterized, for the first time, the differential cytokine expression by these cells in this important complication of pregnancy.

Neutrophil extracellular traps in acute chorioamnionitis: A mechanism of host defense

PROBLEM

Neutrophil extracellular traps (NETs) were recently described as a mechanism for microbial killing in the amniotic cavity of women with intra-amniotic infection. Such a clinical condition can result in acute chorioamnionitis, a placental lesion characterized by the infiltration of maternal neutrophils in the chorioamniotic membranes. Herein, we investigated whether these infiltrating neutrophils form NETs in the chorioamniotic membranes from women who underwent spontaneous term or preterm labor with acute chorioamnionitis.

METHOD OF STUDY

Chorioamniotic membrane samples were collected from women who underwent spontaneous term or preterm labor with acute chorioamnionitis (n=10 each). Controls included chorioamniotic membrane samples from women who delivered at term or preterm with or without labor in the absence of acute chorioamnionitis (n=10 each). NETs were visualized and semiquantified in the chorioamniotic membranes by using antibodies against neutrophil elastase and histone H3 in combination with DAPI staining.

RESULTS

Neutrophil extracellular traps were abundant in the chorioamniotic membranes from women who underwent spontaneous term or preterm labor with acute chorioamnionitis. NETs were rarely found, or not visualized at all, in the chorioamniotic membranes from women who delivered at term or preterm with or without labor in the absence of acute chorioamnionitis.

CONCLUSION

Neutrophil extracellular traps are abundant in the chorioamniotic membranes from women who underwent spontaneous term or preterm labor with acute chorioamnionitis. These findings suggest that chorioamniotic neutrophils can form NETs as a mechanism of host defense against infection or danger signals.

FGR in the setting of preterm sterile intra-uterine milieu is associated with a decrease in RDS

OBJECTIVE

To determine if fetal growth restriction (FGR) in the setting of sterile intra-uterine milieu would be associated with a decrease in respiratory distress syndrome (RDS) of preterm-neonates.

METHODS

The relationship between FGR and neonatal RDS was examined in 92 singleton preterm-neonates (gestational age [GA]: 24.5-33.4 weeks) born to mothers with sterile intra-uterine milieu, which consisted of both sterile amniotic fluid (AF), and inflammation-free placenta. Sterile AF was defined in the absence of both infection and inflammation in AF. AF inflammation was defined in the presence of AF MMP-8 ≥23 ng/ml. FGR was defined in the presence of birth-weight (BW) below the 5th percentile for GA.

RESULTS

FGR was present in 32% and RDS was found in 46% of patients. RDS was less common (24% vs. 56%; P < 0.01) and umbilical arterial pH at birth ≤7.15 was more common (33% vs. 13%; P < 0.05) in preterm-neonates with FGR than in those without FGR. There is a stepwise increase in RDS with increasing BW (i.e., below the 5th percentile, the 5th ∼10th percentile, and above the 10th percentile for GA) (P < 0.01, linear by linear association). Logistic regression analysis demonstrated that FGR was a better independent predictor of a decrease in RDS (OR = 0.049, 95%CI 0.009-0.259, P < 0.0005) than advanced GA at delivery (OR = 0.584, 95%CI 0.423-0.806, P < 0.005) after adjusting for other confounding variables.

CONCLUSION

FGR in the setting of sterile intra-uterine milieu is associated with a decrease in RDS of preterm-neonates. This observation suggests that chronic intra-uterine hypoxic stress related to FGR may be beneficial to fetal lung maturation. Pediatr Pulmonol. 2016;51:812-819. © 2015 Wiley Periodicals, Inc.

Preterm labor and preterm premature rupture of membranes have a different pattern in the involved compartments of acute histologoic chorioamnionitis and/or funisitis: Patho-physiologic implication related to different clinical manifestations

It is unknown whether histo-topographic findings about the involved compartments (i.e., choriodecidua, amnion, chorionic-plate) of acute-histologic chorioamnionitis (acute-HCA) and/or funisitis according to the presence or absence of intra-amniotic inflammation (IAI) and/or fetal inflammatory response syndrome (FIRS) are different between preterm labor and intact membranes (PTL) and preterm premature rupture of membranes (preterm-PROM). The involved compartments of acute-HCA and/or funisitis were examined in 161 singleton preterm-births (<34 weeks) due to PTL (n = 88) and preterm-PROM (n = 73). The study-population was divided into IAI(-)/FIRS(-), IAI(+)/FIRS(-), and IAI(+)/FIRS(+) groups according to the presence or absence of IAI (amniotic-fluid MMP-8 ≥ 23 ng/ml) and/or FIRS (umbilical-cord plasma CRP ≥ 200 ng/ml). Histological inflammation was not detected in any-compartment except choriodecidua in IAI(-)/FIRS(-) group with PTL while inflammation appeared in all-compartment0s (choriodeciduitis-46.2 %; amnionitis-23.1 %; funisitis-30.8 %; chorionic-plate inflammation-7.7 %) in IAI(-)/FIRS(-) group with preterm-PROM. IAI(+)/FIRS(-) group had a significantly higher frequency of inflammation in each-compartment than IAI(-)/FIRS(-) group in PTL (each-for P < 0.01), but not preterm-PROM (each-for P > 0.1). However, IAI(+)/FIRS(+) group had a significantly higher rate of inflammation in each compartment than IAI(+)/FIRS(-) group in both PTL and preterm-PROM (each-for P < 0.05). We first demonstrated that PTL and preterm-PROM had a different pattern in the involved compartments of acute-HCA and/or funisitis in the IAI(-)/FIRS(--) group and in the change of involved compartments from IAI(-)/FIRS(-) to IAI(+)/FIRS(-).

About one-half of early spontaneous preterm deliveries can be identified by a rapid matrix metalloproteinase-8 (MMP-8) bedside test at the time of mid-trimester genetic amniocentesis

OBJECTIVE

Mid-trimester amniocentesis continues to be used for the prenatal diagnosis of chromosomal anomalies and other genetic disorders. Analysis of amniotic fluid obtained at the time of mid-trimester genetic amniocentesis identifies those patients who are at risk for early spontaneous preterm delivery. This is based on a solid body of evidence that found subclinical intra-amniotic inflammation/infection to be causally linked to early spontaneous preterm birth. Although several biomarkers have been proposed to identify intra-amniotic inflammation, the accumulated data suggest that the determination of amniotic fluid matrix metalloproteinase-8 (MMP-8), or neutrophil collagenase, is a powerful predictor of spontaneous preterm delivery. MMP-8 is released by inflammatory cells in response to microbial products or "danger signals". A rapid point-of-care test has been developed to determine MMP-8 at the bedside within 20 min, and without the requirement of laboratory equipment. The objective of this study was to determine whether an elevation of MMP-8 in the amniotic fluid, measured by a rapid point-of-care test, can identify those patients at risk for spontaneous preterm delivery after a mid-trimester genetic amniocentesis.

STUDY DESIGN

A case-control study was designed to obtain amniotic fluid from asymptomatic singleton pregnant women who underwent mid-trimester genetic amniocentesis. An MMP-8 bedside test was performed to analyze the amniotic fluid of 64 patients with early spontaneous preterm delivery (<30 weeks) and 128 matched controls with normal pregnancy outcomes.

RESULTS

(1) The MMP-8 bedside test (Yoon's MMP-8 Check™) was positive in 42.2% (27/64) of patients with spontaneous preterm delivery but in none (0/128) of the control cases (p < 0.001); (2) the MMP-8 bedside test had a sensitivity of 42.2%, and a specificity of 100% in the prediction of spontaneous preterm delivery (<30 weeks) following a mid-trimester genetic amniocentesis; and (3) among the patients with spontaneous preterm delivery, those with a positive MMP-8 bedside test had a significantly higher rate of spontaneous delivery within 2 weeks and 4 weeks of an amniocentesis [40.7% (11/27) versus 5.4% (2/37); 63.0% (17/27) versus 24.3% (9/37)] and a shorter interval-to-delivery period than those with a negative test [interval-to-delivery: median (range), 16 d (0-95 d) versus 42 d (2-91 d); p < 0.05 for each].

CONCLUSION

We conclude that 42% of patients with an early spontaneous preterm delivery (< 30 weeks) could be identified by a rapid MMP-8 bedside test at the time of their mid-trimester genetic amniocentesis. The MMP-8 bedside test is a powerful predictor of early spontaneous preterm birth in asymptomatic pregnant women.

A new antibiotic regimen treats and prevents intra-amniotic inflammation/infection in patients with preterm PROM

OBJECTIVES

To determine whether a new antibiotic regimen could reduce the frequency of intra-amniotic inflammation/infection in patients with preterm PROM.

STUDY DESIGN

This retrospective cohort study was conducted to evaluate the effect of antibiotics on the frequency of intra-amniotic inflammation/infection based on the results of follow-up transabdominal amniocenteses from 89 patients diagnosed with preterm PROM who underwent serial amniocenteses. From 1993-2003, ampicillin and/or cephalosporins or a combination was used ("regimen 1"). A new regimen (ceftriaxone, clarithromycin and metronidazole) was used from 2003-2012 ("regimen 2"). Amniotic fluid was cultured and matrix metalloproteinase-8 (MMP-8) concentrations were measured.

RESULTS

(1) The rates of intra-amniotic inflammation and intra-amniotic inflammation/infection in patients who received regimen 2 decreased during treatment from 68.8% to 52.1% and from 75% to 54.2%, respectively. In contrast, in patients who received regimen 1, the frequency of intra-amniotic inflammation and infection/inflammation increased during treatment (31.7% to 55% and 34.1% to 58.5%, respectively); and (2) intra-amniotic inflammation/infection was eradicated in 33.3% of patients who received regimen 2, but in none who received regimen 1.

CONCLUSION

The administration of ceftriaxone, clarithromycin and metronidazole was associated with a more successful eradication of intra-amniotic inflammation/infection and prevented secondary intra-amniotic inflammation/infection more frequently than an antibiotic regimen which included ampicillin and/or cephalosporins in patients with preterm PROM.

The effect of labor and delivery on white blood cell count

OBJECTIVE

To explore post-partum white blood cell (WBC) count, and possible factors affecting it.

STUDY DESIGN

Retrospective cohort analysis of 12 079 healthy women, delivering a singleton term fetus with an uncomplicated course of labor, delivery and puerperium. All women delivered in a single tertiary, university-affiliated medical center from 2009 to 2014. Student's t-test, Mann-Whitney's U-test, χ(2) test and ANOVA were used to compare between variables. Multiple variable analyses was performed to allow adjustment for potential covariates and confounders. The main outcome measures included post-partum WBC count and the difference in the post-partum versus ante-partum WBC count, in association to mode of delivery, type of analgesia, timing of cesarean delivery and perineal trauma.

RESULTS

The mean post-partum WBC count was 13.39 ± .24 × 10(9)/L (range 1.20-37.30 × 10(9)/L). There is a significant increase in the WBC after delivery (2.1 9 ± 3.33 × 10(9)/L) with significant differences according to mode of delivery (2.34 ± 3.48, 3.32 ± 3.69 and 1.6 0 ± 2.87 × 10(9)/L for spontaneous, assisted and cesarean deliveries. Multiple variables can affect post-partum leukocytosis, including: age, parity, gestational age, mode of delivery, type of anesthesia, timing of cesarean delivery in relation to labor onset and the extent of perineal trauma.

CONCLUSIONS

Post-partum leukocytosis is a physiological phenomenon with a wide normal variation and multiple contributing factors. As a single parameter, post-partum leukocytosis should not prompt further work up.

Timing of Histologic Progression from Chorio-Deciduitis to Chorio-Deciduo-Amnionitis in the Setting of Preterm Labor and Preterm Premature Rupture of Membranes with Sterile Amniotic Fluid

Background

Histologic chorio-deciduitis and chorio-deciduo-amnionitis (amnionitis) in extra-placental membranes are known to represent the early and advanced stages of ascending intra-uterine infection. However, there are no data in humans about the time required for chorio-deciduitis to develop and for chorio-deciduitis without amnionitis to progress to chorio-deciduitis with amnionitis, and the effect of prolongation of pregnancy on the development of chorio-deciduitis and amnionitis in patients with preterm labor and intact membranes (PTL) and preterm premature rupture of membranes (preterm-PROM). We examined these issues in this study.

Methods

The study population consisted of 289 women who delivered preterm (133 cases with PTL, and 156 cases with preterm-PROM) and who had sterile amniotic fluid (AF) defined as a negative AF culture and the absence of inflammation as evidenced by a matrix metalloproteinase-8 (MMP-8) level <23 ng/ml. We examined the association between amniocentesis-to-delivery interval and inflammatory status in the extra-placental membranes (i.e., inflammation-free extra-placental membranes, choroi-deciduitis only, and chorio-deciduitis with amnionitis) in patients with PTL and preterm-PROM.

Results

Amniocentesis-to-delivery interval was longer in cases of chorio-deciduitis with amnionitis than in cases of chorio-deciduitis only in both PTL (median [interquartile-range (IQR)]; 645.4 [319.5] vs. 113.9 [526.9] hours; P = 0.005) and preterm-PROM (131.3 [135.4] vs. 95.2 [140.5] hours; P<0.05). Amniocentesis-to-delivery interval was an independent predictor of the development of both chorio-deciduitis and amnionitis after correction for confounding variables such as gestational age at delivery in the setting of PTL, but not preterm-PROM.

Conclusions

These data confirm for the first time that, in cases of both PTL and preterm-PROM with sterile AF, more time is required to develop chorio-deciduitis with amnionitis than chorio-deciduitis alone in extra-placental membranes. Moreover, prolongation of pregnancy is an independent predictor of the development of both chorio-deciduitis and amnionitis in cases of PTL with sterile AF.

Acute chorioamnionitis and funisitis: definition, pathologic features, and clinical significance

Acute inflammatory lesions of the placenta consist of diffuse infiltration of neutrophils at different sites in the organ. These lesions include acute chorioamnionitis, funisitis, and chorionic vasculitis and represent a host response (maternal or fetal) to a chemotactic gradient in the amniotic cavity. While acute chorioamnionitis is evidence of a maternal host response, funisitis and chorionic vasculitis represent fetal inflammatory responses. Intraamniotic infection generally has been considered to be the cause of acute chorioamnionitis and funisitis; however, recent evidence indicates that "sterile" intraamniotic inflammation, which occurs in the absence of demonstrable microorganisms induced by "danger signals," is frequently associated with these lesions. In the context of intraamniotic infection, chemokines (such as interleukin-8 and granulocyte chemotactic protein) establish a gradient that favors the migration of neutrophils from the maternal or fetal circulation into the chorioamniotic membranes or umbilical cord, respectively. Danger signals that are released during the course of cellular stress or cell death can also induce the release of neutrophil chemokines. The prevalence of chorioamnionitis is a function of gestational age at birth, and present in 3-5% of term placentas and in 94% of placentas delivered at 21-24 weeks of gestation. The frequency is higher in patients with spontaneous labor, preterm labor, clinical chorioamnionitis (preterm or term), or ruptured membranes. Funisitis and chorionic vasculitis are the hallmarks of the fetal inflammatory response syndrome, a condition characterized by an elevation in the fetal plasma concentration of interleukin-6, and associated with the impending onset of preterm labor, a higher rate of neonatal morbidity (after adjustment for gestational age), and multiorgan fetal involvement. This syndrome is the counterpart of the systemic inflammatory response syndrome in adults: a risk factor for short- and long-term complications (ie, sterile inflammation in fetuses, neonatal sepsis, bronchopulmonary dysplasia, periventricular leukomalacia, and cerebral palsy). This article reviews the definition, pathogenesis, grading and staging, and clinical significance of the most common lesions in placental disease. Illustrations of the lesions and diagrams of the mechanisms of disease are provided.

A new anti-microbial combination prolongs the latency period, reduces acute histologic chorioamnionitis as well as funisitis, and improves neonatal outcomes in preterm PROM

OBJECTIVE

Antibiotic administration is a standard practice in preterm premature rupture of membranes (PROM). Specific anti-microbial agents often include ampicillin and/or erythromycin. Anaerobes and genital mycoplasmas are frequently involved in preterm PROM, but are not adequately covered by antibiotics routinely used in clinical practice. Our objective was to compare outcomes of PROM treated with standard antibiotic administration versus a new combination more effective against these bacteria.

STUDY DESIGN

A retrospective study compared perinatal outcomes in 314 patients with PROM <34 weeks receiving anti-microbial regimen 1 (ampicillin and/or cephalosporins; n = 195, 1993-2003) versus regimen 2 (ceftriaxone, clarithromycin and metronidazole; n = 119, 2003-2012). Intra-amniotic infection/inflammation was assessed by positive amniotic fluid culture and/or an elevated amniotic fluid MMP-8 concentration (>23 ng/mL).

RESULTS

(1) Patients treated with regimen 2 had a longer median antibiotic-to-delivery interval than those with regimen 1 [median (interquartile range) 23 d (10-51 d) versus 12 d (5-52 d), p < 0.01]; (2) patients who received regimen 2 had lower rates of acute histologic chorioamnionitis (50.5% versus 66.7%, p < 0.05) and funisitis (13.9% versus 42.9%, p < 0.001) than those who had received regimen 1; (3) the rates of intra-ventricular hemorrhage (IVH) and cerebral palsy (CP) were significantly lower in patients allocated to regimen 2 than regimen 1 (IVH: 2.1% versus 19.0%, p < 0.001 and CP: 0% versus 5.7%, p < 0.05); and (4) subgroup analysis showed that regimen 2 improved perinatal outcomes in pregnancies with intra-amniotic infection/inflammation, but not in those without intra-amniotic infection/inflammation (after adjusting for gestational age and antenatal corticosteroid administration).

CONCLUSION

A new antibiotic combination consisting of ceftriaxone, clarithromycin, and metronidazole prolonged the latency period, reduced acute histologic chorioamnionitis/funisitis, and improved neonatal outcomes in patients with preterm PROM. These findings suggest that the combination of anti-microbial agents (ceftriaxone, clarithromycin, and metronidazole) may improve perinatal outcome in preterm PROM.

A transcervical amniotic fluid collector: a new medical device for the assessment of amniotic fluid in patients with ruptured membranes

AIM

To describe a new device for the transcervical collection of amniotic fluid (AF) in patients with ruptured membranes, and to compare the concentration of proteins in fluid retrieved by transabdominal amniocentesis and the transcervical AF collector.

STUDY DESIGN

Paired AF samples were collected in patients with preterm prelabor rupture of membranes (PROM) (n=11) by transabdominal amniocentesis and with the transcervical AF collector (Yoon's AF Collector™). Three proteins known to have high concentrations in AF [α-fetoprotein (AFP), β-human chorionic gonadotrophin (β-hCG), and prolactin] were measured.

RESULTS

(1) There was a significant correlation between the concentrations of analytes in AF obtained by transabdominal amniocentesis and by the transcervical AF collector (r=0.94, P<0.001 for AFP; r=0.96, P<0.001 for β-hCG; r=0.72, P<0.05 for prolactin); (2) Bland-Altman plots showed no evidence of heteroscedasticity between transabdominal or transcervical AF concentrations of these markers.

CONCLUSIONS

There was a strong correlation between the concentrations of proteins in AF collected by amniocentesis or with the transcervical device.

Mild to Moderate, but Not Minimal or Severe, Acute Histologic Chorioamnionitis or Intra-Amniotic Inflammation Is Associated with a Decrease in Respiratory Distress Syndrome of Preterm Newborns without Fetal Growth Restriction

BACKGROUND

Acute histologic chorioamnionitis (acute-HCA) is known to be associated with a decreased risk of respiratory distress syndrome (RDS) in newborns. However, there is no information about whether the severity of acute-HCA or intra-amniotic inflammation (IAI) is associated with the development of RDS.

OBJECTIVES

To assess the relationship between the severity of acute-HCA or IAI and the development of RDS in preterm newborns due to preterm labor and intact membranes (PTL) or preterm premature rupture of membranes (preterm-PROM) without fetal growth restriction (FGR).

METHODS

The frequency of RDS was examined in 378 singleton preterm neonates (24.5-34 weeks' gestation) due to PTL or preterm-PROM without FGR. Patients were divided into 4 groups according to the severity of acute-HCA (i.e. total grade: minimal, 1; mild, 2; moderate, 3-4; severe, 5-6) or IAI (i.e. amniotic fluid MMP-8: minimal, 23-100 ng/ml; mild, 100-400 ng/ml; moderate, 400-800 ng/ml; severe, ≥800 ng/ml). Amniotic fluid MMP-8 was measured in 196 patients delivered within 7 days of amniocentesis.

RESULTS

Mild to moderate, but not minimal or severe, acute-HCA (minimal, 24%; mild, 13%; moderate, 19%; severe, 41%; preterm-reference group, 26%) or IAI (minimal, 24%; mild, 11%; moderate, 17%; severe, 25%; preterm reference group, 23%) was associated with a significant decrease in RDS as compared with the preterm reference group (each for p < 0.05 after the adjustment of gestational age at delivery, antenatal corticosteroid use, newborn gender, cesarean delivery and preterm-PROM as a cause of preterm birth).

CONCLUSIONS

Mild to moderate, but not minimal or severe, acute-HCA or IAI is associated with a significant decrease in RDS among preterm neonates due to PTL or preterm-PROM without FGR.

The relationship between the intensity of intra-amniotic inflammation and the presence and severity of acute histologic chorioamnionitis in preterm gestation

OBJECTIVE

Acute histologic chorioamnionitis (HCA) is associated with an increased risk of perinatal mortality and morbidity. The purpose of this study was to determine the relationship between the intensity of intra-amniotic inflammation (IAI) and the severity of acute HCA in preterm gestation.

METHODS

The relationship between the intensity of IAI and the presence and severity of acute HCA was examined in 412 patients with singleton gestations who delivered within 120 h of transabdominal amniocentesis. The concentration of amniotic fluid (AF) matrix metalloproteinase (MMP)-8 was assayed to determine the presence and intensity of IAI. Acute HCA was defined as the presence of inflammatory change in any tissue samples according to the criteria previously reported. The total grade of acute HCA was used to determine the severity of HCA.

RESULTS

(1) Patients with IAI had a significantly higher rate of acute HCA than those without IAI [76.9% (133/173)] versus 20.9% (50/239), p < 0.001]. The AF MMP-8 concentration was significantly higher in patients with acute HCA than in those without acute HCA (median [range]; 188.3 ng/ml [0.3-6142.6] versus 1.8 ng/ml [0.3-2845.5], p < 0.001); (2) Of 183 patients with acute HCA, the AF MMP-8 concentration was positively correlated with the severity of acute HCA (p < 0.001).

CONCLUSIONS

AF MMP-8 concentration was not only a predictor of the presence of acute HCA, but its concentration also correlated with the severity of acute HCA. The higher the intensity of IAI, the worse the degree of acute HCA in preterm gestation.