Intraamniotic Inflammation in Women with Preterm Prelabor Rupture of Membranes

Angiogenic imbalance in pregnancies with preterm prelabor rupture of membranes between 34 and 37 weeks of gestation

INTRODUCTION

This study aimed to identify whether microbial invasion of the amniotic cavity and/or intra-amniotic inflammation in women with late preterm prelabor rupture of membranes (PPROM) was associated with changes in concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and its ratio in maternal serum, and whether placental features consistent with maternal vascular malperfusion further affect their concentrations.

MATERIAL AND METHODS

This historical study included 154 women with singleton pregnancies complicated by PPROM between gestational ages 34+0 and 36+6 weeks. Transabdominal amniocentesis was performed as part of standard clinical management to evaluate the intra-amniotic environment. Women were categorized into two subgroups based on the presence of microorganisms and/or their nucleic acids in amniotic fluid (determined by culturing and molecular biology method) and intra-amniotic inflammation (by amniotic fluid interleukin-6 concentration evaluation): (1) those with the presence of microorganisms and/or inflammation (at least one present) and (2) those with negative amniotic fluid for infection/inflammation (absence of both). Concentrations of sFlt-1 and PlGF were assessed using the Elecsys® sFlt-1 and Elecsys® PlGF immunoassays and converted into multiples of medians.

RESULTS

Women with the presence of microorganisms and/or inflammation in amniotic fluid had lower serum concentrations of sFlt-1 and sFlt-1/PlGF ratios and higher concentrations of PlGF compared with those with negative amniotic fluid. (sFlt-1: presence: median 1.0 multiples of the median (MoM), vs negative: median: 1.5 MoM, P = 0.003; PlGF: presence: median 0.7 MoM, vs negative: median 0.4 MoM, P = 0.02; sFlt-1/PlGF: presence: median 8.9 vs negative 25.0, P = 0.001). Higher serum concentrations of sFlt-1 and sFlt-1/PlGF ratios as well as lower concentrations of PlGF were found in the subsets of women with maternal vascular malperfusion than in those without maternal vascular malperfusion.

CONCLUSIONS

Among women experiencing late PPROM, angiogenic imbalance in maternal serum is primarily observed in those without both microbial invasion of the amniotic cavity and intra-amniotic inflammation. Additionally, there is an association between angiogenic imbalance and the presence of maternal vascular malperfusion.

Characterizing of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta marked by elevated amniotic fluid interferon gamma-induced protein 10 (IP-10) in pregnancies complicated by preterm prelabor rupture of membranes

OBJECTIVES

This study aimed to determine the occurrence of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta, marked by elevated levels of interferon gamma-induced protein 10 (IP-10) (≥2200 pg/mL) in the amniotic fluid of women with preterm prelabor rupture of membranes (PPROM). Specifically, the study investigated whether these intra-amniotic inflammatory changes were more common in women with microbial invasion of amniotic cavity (MIAC) and intra-amniotic inflammation (IAI), as indicated by increased amniotic fluid interleukin (IL)-6 concentration (≥3000 pg/mL).

STUDY DESIGN

A cohort of 114 women with singleton pregnancies complicated by PPROM between 24+0 and 36+6 weeks of gestation were included. Amniotic fluid samples were obtained via amniocentesis upon admission. MIAC diagnosis involved aerobic and anaerobic cultures, as well as polymerase chain reaction (PCR) analysis of the amniotic fluid. Immunoassay tests and enzyme-linked immunosorbent assay (ELISA) were used to determine IL-6 and IP-10 concentrations, respectively.

RESULTS

Among the participants, 19.3 % and 15.8 % had MIAC and IAI, respectively. The occurrence of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta was similar between women with and without MIAC (25 % vs. 40.9 %, p = 0.136, adjusted p = 0.213). The rate of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta was significantly higher in women with IAI compared to those without, after adjusting for gestational age at sampling (55.6 % vs. 22.9 %, p = 0.005, adjusted p = 0.011).

CONCLUSION

This study revealed comparable rates of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta in women with and without MIAC, but a higher prevalence of intra-amniotic inflammatory changes associated with chronic inflammation in the placenta in women with IAI. These findings suggest involvement of chronic inflammation even in women with PPROM with acute intra-amniotic inflammation.

In premature rupture of membranes, maternal serum delta neutrophil index may be a predictive factor for histological chorioamnionitis and affect fetal inflammatory markers: A retrospective cross-sectional study

PROBLEM

We aimed to investigate the predictive value of delta neutrophil index (DNI) for histological choriomanionitis (HCAM) and the effect of maternal inflammatory markers on neonatal outcomes and fetal inflammatory parameters.

METHOD OF STUDY

In this retrospective cross-sectional study, 68 pregnant women without HCAM (group 1) and 46 pregnant women diagnosed with HCAM (group 2) were divided into two groups. Demographic stories of the groups; maternal hematological parameters; maternal DNI and systemic inflammatory index (SII) values; outcomes of newborns; fetal inflammatory markers were recorded and compared between groups.

RESULTS

Maternal DNI, and SII levels were significantly higher in group 2 (p value < .05 for all). Admission to the neonatal unit (NICU) was higher in group 2 than in group 1 (p = .0001). We found that fetal inflammatory markers were significantly higher in group 2 (p values .001 for CRP, .0001 for DNI, and .002 for leukocyte). Maternal DNI was determined to be significantly diagnostic at a value of ≥1.3 in HCAM (p = .001). We observed that SII had a significant predictive value of 953036.6 (p = .019) for NICU admission. There is also a positive correlation between fetal inflammatory markers and maternal inflammatory markers.

CONCLUSIONS

We found that maternal inflammatory markers are high in HCAM, maternal DNI can predict patients who will develop HCAM, maternal SII value can predict NICU admission, fetal inflammatory markers are high in HCAM, and these markers are affected by maternal inflammatory markers.

Antibiotic treatment reduces the intensity of intraamniotic inflammation in pregnancies with idiopathic vaginal bleeding in the second trimester of pregnancy

BACKGROUND

Idiopathic bleeding in the second trimester of pregnancy complicates <1% of all pregnancies. This pregnancy complication can be caused by alterations in local hemostasis in the decidua due to infection/inflammation in the choriodecidual niche. This condition is associated with intraamniotic inflammatory complications. Antibiotic therapy effectively reduces the intensity of intraamniotic inflammation in certain pregnancy pathologies. However, whether antibiotic administration can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with idiopathic bleeding during the second trimester of pregnancy remains unclear.

OBJECTIVE

This study primarily aimed to determine whether antimicrobial agents can reduce the magnitude of intraamniotic inflammation in patients with idiopathic bleeding in the second trimester of pregnancy by assessing the concentration of interleukin-6 in the amniotic fluid before and after 7 days of antibiotic treatment. The secondary aim was to determine whether treatment with a combination of antibiotics altered the microbial load of Ureaplasma species DNA in amniotic fluid.

STUDY DESIGN

This retrospective cohort study included singleton-gestation patients with idiopathic bleeding between 15+0 and 27+6 weeks who underwent transabdominal amniocentesis at the time of admission. Follow-up amniocentesis was performed in a subset of patients unless abortion or delivery occurred earlier. Concentrations of interleukin-6 were measured in the amniotic fluid samples, and the presence of microbial invasion of the amniotic cavity was assessed using culture and molecular microbiological methods. Intraamniotic inflammation was defined as an interleukin-6 concentration ≥3000 pg/mL in the amniotic fluid samples.

RESULTS

A total of 36 patients with idiopathic bleeding in the second trimester of pregnancy were included. All the patients underwent initial amniocentesis. Patients with intraamniotic inflammation (n=25) were treated using a combination of antibiotics consisting of intravenous ceftriaxone, intravenous metronidazole, and peroral clarithromycin. The patients without intraamniotic inflammation (n=11) were treated expectantly. In total, 25 patients delivered 7 days after admission. All patients with intraamniotic inflammation at the initial amniocentesis who delivered after 7 days underwent follow-up amniocentesis. Treatment with antibiotics decreased the interleukin-6 concentration in the amniotic fluid at follow-up amniocentesis compared with that at the initial amniocentesis in patients with intraamniotic inflammation (median [interquartile range]: 3457 pg/mL [2493-13,203] vs 19,812 pg/mL [11,973-34,518]; P=.0001). Amniotic fluid samples with Ureaplasma species DNA had a lower microbial load at the time of follow-up amniocentesis compared with the initial amniocentesis (median [interquartile range]: 1.5×105 copies DNA/mL [1.3×105-1.7×105] vs 8.0×107 copies DNA/mL [6.7×106-1.6×108]; P=.02).

CONCLUSION

Antibiotic therapy was associated with reduced intraamniotic inflammation in patients with idiopathic bleeding in the second trimester complicated by intraamniotic inflammation. Moreover, antibiotic treatment has been associated with a reduction in the microbial load of Ureaplasma species DNA in the amniotic fluid.

Potential of plasma inflammatory and angiogenic mediators for predicting spontaneous preterm delivery, intraamniotic infection/inflammation, and composite neonatal morbidity/mortality in women with early preterm premature rupture of membranes

PROBLEM

To assess the potential of five inflammatory and six angiogenic/antiangiogenic plasma proteins for predicting imminent spontaneous preterm delivery (SPTD; ≤14 days of sampling), microbial invasion of the amniotic cavity and/or intraamniotic inflammation (MIAC/IAI), and composite neonatal morbidity and mortality (CNMM) in women with early preterm premature rupture of membranes (PPROM).

METHODS OF STUDY

This retrospective cohort study included 76 singleton pregnant women with early PPROM (23-30 weeks). Amniotic fluid obtained via amniocentesis was cultured for microorganism detection and assayed for interleukin-6 to define IAI (≥2.6 ng/mL). Plasma C4a, endoglin, endostatin, IGFBP-1, IGFBP-2, MMP-9, PlGF, S100A8, S100A9, S100 A8/A9, and VEGFR-1 levels were determined using ELISA.

RESULTS

Multivariate logistic regression analyses revealed significant associations between (i) high levels of plasma S100A8/A9, SPTD ≤14 days after sampling, and shorter sampling-to-delivery intervals; (ii) elevated plasma MMP-9, S100A9, and S100A8/A9 levels and MIAC/IAI, and (iii) decreased plasma endoglin levels and increased CNMM risk, while adjusting for gestational age at sampling (or delivery) and tocolytic use. The area under the curves of the aforementioned proteins ranged from 0.655 to 0.731 for each outcome. Notably, the SPTD risk increased significantly with increasing plasma S100A8/A9 levels (P for trend < .05).

CONCLUSIONS

Plasma S100A8/A9, MMP-9, S100A9, and endoglin may represent valuable biomarkers associated with SPTD, MIAC/IAI, and CNMM in women with early PPROM. Owing to their less invasive nature, repeatability, and fair-to-moderate diagnostic accuracy, these biomarkers may contribute to risk stratification of PPROM-related complications in the clinical setting.

Microplastics and additives in patients with preterm birth: The first evidence of their presence in both human amniotic fluid and placenta

Considering the well documented, almost ubiquitous nature of microplastics in different environments, the exposure of pregnant women to microplastics may pose risks to the unborn children. The study focused on investigating the presence of microplastics in amniotic fluid and placenta, and brings the first evidence of the simultaneous presence of microplastics and additives in both human amniotic fluid and placentas. In total, 20 samples of amniotic fluid and placenta from 10 patients were analyzed for the presence of microplastics and plastic additives by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) after alkaline digestion with KOH. In 9 out of 10 patients, microplastics or additives were found in amniotic fluid, placenta, or both. Specifically, 44 particles of microplastics and polymer additives were identified in all samples. Chlorinated Polyethylene (CPE) and Calcium zinc PVC Stabilizer with particle sizes between 10 and 50 μm prevailed. Although all women involved in this study, who provided placenta and amniotic fluid samples, experienced physiological, singleton pregnancies complicated with preterm prelabour rupture of membranes (PPROM), it is too early to draw any conclusions and more research is needed.

Amniotic fluid CD36 in pregnancies complicated by spontaneous preterm delivery: a retrospective cohort study

OBJECTIVE

The aim of this study was to evaluate CD36 concentrations in amniotic fluid in pregnancies complicated by spontaneous delivery with intact fetal membranes (preterm labor, PTL) and preterm prelabor rupture of membranes (PPROM) with respect to the presence of the intra-amniotic infection.

METHODS

A total of 80 women with PPROM and 71 with PTL were included in the study. Amniotic fluid samples were obtained by transabdominal amniocentesis. Amniotic fluid CD36 concentrations were assessed by enzyme-linked immunosorbent assay. Microbial colonization of the amniotic cavity (MIAC) was determined by the cultivation and non-cultivation approach. Intra-amniotic inflammation (IAI) was defined as an amniotic fluid bedside interleukin-6 concentration ≥3000 pg/mL. Intra-amniotic infection was characterized by the presence of both MIAC and IAI.

RESULTS

Women with PPROM with intra-amniotic infection had higher amniotic fluid CD36 concentrations than women without infection (with infection: median 346 pg/mL, IQR 262-384 vs. without infection: median 242 pg/mL, IQR 199-304; p = .006) A positive correlation between amniotic fluid CD36 concentrations and interleukin-6 concentrations was found (rho = 0.48; p < .0001). In PTL pregnancies, no statistically significant difference was found in the amniotic fluid level of CD36 between intra-amniotic infection, sterile IAI, and negative amniotic fluid.

CONCLUSIONS

The presence of intra-amniotic infection is characterized by higher amniotic fluid CD36 concentrations in pregnancies complicated by PPROM. An amniotic fluid CD36 cutoff value of 252.5 pg/mL was found to be optimal for the prediction of intra-amniotic infection. In PTL pregnancies, no statistically significant change in CD36 concentration was found with respect to the presence of intra-amniotic infection.

Cervical excisional treatment increases the risk of intraamniotic infection in subsequent pregnancy complicated by preterm prelabor rupture of membranes

BACKGROUND

Excisional treatment of cervical intraepithelial neoplasia or very early stages of cervical cancer increases the risk of preterm prelabor rupture of membranes in subsequent pregnancies. The risk increases with the length of the excised cone. The subset of cases with preterm prelabor rupture of membranes and a history of cervical excisional treatment could also be at higher risk of intraamniotic infection/inflammation. However, there is a paucity of relevant information on this subject.

OBJECTIVE

This study aimed to assess the differences in the rates of intraamniotic infection/inflammation and early-onset neonatal sepsis between singleton preterm prelabor rupture of membranes pregnancies without and with a history of cervical excisional treatment, and to investigate the association between these complications of preterm prelabor rupture of membranes and the excised cone length.

STUDY DESIGN

This retrospective cohort study included 770 preterm prelabor rupture of membranes pregnancies in which transabdominal amniocentesis was performed as part of standard clinical management to assess the intraamniotic environment. The maternal and perinatal medical records of all included women were reviewed to obtain information on the absence or presence of history of cervical excisional treatment and neonatal outcomes. Women whose records contained any information on history of cervical excisional treatment were contacted by phone and in writing to inform them of the study and request permission to collect relevant information from their medical records. Women were divided into 4 subgroups according to the presence of microorganisms and/or their nucleic acids (through culturing and molecular biology methods) in amniotic fluid and/or intraamniotic inflammation (through amniotic fluid interleukin-6 concentration evaluation): intraamniotic infection (presence of both), sterile intraamniotic inflammation (intraamniotic inflammation alone), microbial invasion of the amniotic cavity without inflammation (presence of microorganisms and/or their nucleic acids in amniotic fluid alone), and negative amniotic fluid for infection/inflammation (absence of both).

RESULTS

A history of cervical excisional treatment was found in 10% (76/765) of the women. Of these, 82% (62/76) had a history of only 1 treatment, and information on cone length was available for 97% (60/62) of them. Women with a history of cervical excisional treatment had higher rates of intraamniotic infection (with, 25% [19/76] vs without, 12% [85/689]; adjusted odds ratio, 2.5; adjusted P=.004), microbial invasion of the amniotic cavity without inflammation (with, 25% [19/76] vs without, 11% [74/689]; adjusted odds ratio, 3.1; adjusted P<.0001), and early-onset neonatal sepsis (with, 8% [11/76] vs without, 3% [23/689]; adjusted odds ratio, 2.9; adjusted P=.02) compared with those without such history. Quartiles of cone length (range: 3-32 mm) were used to categorize the women into 4 quartile subgroups (first: 3-8 mm; second: 9-12 mm; third: 13-17 mm; and fourth: 18-32 mm). Cone length of ≥18 mm was associated with higher rates of intraamniotic infection (with, 29% [5/15] vs without, 12% [85/689]; adjusted odds ratio, 3.0; adjusted P=.05), microbial invasion of the amniotic cavity without inflammation (with, 40% [6/15] vs without, 11% [74/689]; adjusted odds ratio, 6.1; adjusted P=.003), and early-onset neonatal sepsis (with, 20% [3/15] vs without, 3% [23/689]; adjusted odds ratio, 5.7; adjusted P=.02).

CONCLUSION

History of cervical excisional treatment increases risks of intraamniotic infection, microbial invasion of the amniotic cavity without inflammation, and development of early-onset neonatal sepsis in a subsequent pregnancy complicated by preterm prelabor rupture of membranes.

Directive clinique no 430 : Diagnostic et prise en charge de la rupture prématurée des membranes avant terme

OBJECTIF

Fournir des directives claires et concises pour le diagnostic et la prise en charge de la rupture prématurée des membranes avant terme (RPMAT).

POPULATION CIBLE

Toute patiente manifestant une rupture prématurée des membranes avant 37 semaines d'aménorrhée. BéNéFICES, RISQUES ET COûTS: La présente directive clinique vise à fournir les premières recommandations générales canadiennes sur la prise en charge de la rupture des membranes avant terme. Elle repose sur un examen complet et à jour des données probantes sur le diagnostic de la rupture et sur la prise en charge, le bon moment et les modes d'accouchement. DONNéES PROBANTES: Des recherches ont été effectuées dans PubMed-Medline et Cochrane en 2021 en utilisant les termes suivants : preterm premature rupture of membranes, PPROM, chorioamnionitis, Nitrazine test, ferning, commercial tests, PAMG-1, IGFBP-1 test, ultrasonography, PPROM/antenatal corticosteroids, PPROM/Magnesium sulphate, PPROM/antibiotic treatment, PPROM/tocolysis, PPROM/preterm labour, PPROM/neonatal outcomes, PPROM/mortality, PPROM/outpatient/inpatient, PPROM/cerclage, previable PPROM. Les articles retenus sont des essais cliniques randomisés, des méta-analyses, des revues systématiques, des directives cliniques et des études observationnelles. D'autres publications pertinentes ont été sélectionnées à partir des notices bibliographiques de ces articles. Seuls les articles en anglais ont été examinés. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins de santé prénatale ou périnatale. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Guideline No. 430: Diagnosis and management of preterm prelabour rupture of membranes

OBJECTIVE

To provide clear and concise guidelines for the diagnosis and management of preterm prelabour rupture of membranes (PPROM) TARGET POPULATION: All patients with PPROM <37 weeks gestation BENEFITS, HARMS, AND COSTS: This guideline aims to provide the first Canadian general guideline on the management of preterm membrane rupture. It includes a comprehensive and up-to-date review of the evidence on the diagnosis, management, timing and method of delivery.

EVIDENCE

The following search terms were entered into PubMed/Medline and Cochrane in 2021: preterm premature rupture of membranes, PPROM, chorioamnionitis, Nitrazine test, ferning, commercial tests, placental alpha microglobulin-1 (PAMG-1) test, insulin-like growth factor-binding protein-1 (IGFBP-1) test, ultrasonography, PPROM/antenatal corticosteroids, PPROM/Magnesium sulphate, PPROM/ antibiotic treatment, PPROM/tocolysis, PPROM/preterm labour, PPROM/Neonatal outcomes, PPROM/mortality, PPROM/outpatient/inpatient, PPROM/cerclage, previable PPROM. Articles included were randomized controlled trials, meta-analyses, systematic reviews, guidelines, and observational studies. Additional publications were identified from the bibliographies of these articles. Only English-language articles were reviewed.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All prenatal and perinatal health care providers.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Amniopatch as an active treatment of spontaneous previable rupture of membranes

OBJECTIVE

To assess the use of amniopatch - intraamniotic application of maternal platelets and cryoprecipitate, in patients after spontaneous previable rupture of membranes (sPPPROM) in terms of its effect on the course and outcome of pregnancy in the largest cohort so far. Since the amniopatch is currently used only to treat patients with iatrogenic preterm rupture of membranes, aim of this study was to find out, if amniopatch could be also used in case of sPPPROM as a safe alternative to currently used expectant management and to compare the results with published data on expectant management.

METHODS

The study included 53 patients with single-fetal pregnancy after sPPPROM who underwent amniopatch as an experimental method in the years 2008-2019. Authors evaluated individual characteristics for the whole group as well as a subgroup of live-born neonates who survived to discharge and abortions/live-born infants who did not survive to discharge.

RESULTS

The mean time of sPPPROM was 19 + 3 gestational week (gw) and of amniopatch performance 22 + 0 gw. Across the group, the miscarriage rate was 33.96%, survival rate 66.03%, mortality rate after delivery 8.57%, survival rate to discharge 60.37%. The mean time of latency period was 5 + 3 gw in the total group, 7 + 1 gw in the group of live births who survived to discharge. We did not find any maternal/fetal complications related directly to amniopatch procedure.

CONCLUSION

Amniopatch is a safe treatment alternative in patients with sPPPROM who require an active approach. It is associated with high percentage of a success rate in terms of duration of pregnancy and neonatal survival. In order to elucidate the possible mechanism of amniopatch effect in sPPPROM despite failure of complete sealing of membrane defect, authors give novel hypothesis of antimicrobial effect of amniopatch based on literature data.

Calprotectin levels in amniotic fluid in relation to intra-amniotic inflammation and infection in women with preterm labor with intact membranes: A retrospective cohort study

OBJECTIVE

To evaluate the concentrations of calprotectin in amniotic fluid with respect to intra-amniotic inflammation and infection and to assess the presence or absence of bacteria in the amnio-chorionic niche with respect to presence or absence of intra-amniotic inflammation.

STUDY DESIGN

Seventy-nine women with singleton pregnancies and preterm labor with intact membranes (PTL) were included in the study. Amniotic fluid was collected at the time of admission by amniocentesis and calprotectin levels were analyzed from frozen/thawed samples using ELISA. Interleukin (IL)-6 concentration was measured by point-of-care test. Samples from amniotic fluid and the amnio-chorionic niche (space between amniotic and chorionic membranes) were microbiologically analyzed. Microbial invasion of the amniotic cavity (MIAC) was diagnosed based on a positive PCR result for Ureaplasma species, Mycoplasma hominis, 16S rRNA or positive culture. Intra-amniotic inflammation (IAI) was defined as amniotic fluid point-of-care IL-6 concentration ≥ 745 pg/mL. The cohort of included women was divided into 4 subgroups based on the presence or absence of IAI/MIAC; i) intra-amniotic infection, ii) sterile IAI, iii) intra-amniotic colonization and iv) neither MIAC nor IAI.

RESULTS

Women with intra-amniotic infection had a significantly higher intra-amniotic calprotectin concentration (median; 101.6 µg/mL) compared with women with sterile IAI (median; 9.2 µg/mL), women with intra-amniotic colonization (median; 2.6 µg/mL) and women with neither MIAC nor IAI (median 4.6 µg/mL) (p = 0.001). Moreover, significantly higher amniotic fluid calprotectin concentration was seen in women who delivered within 7 days (p = 0.003). A significant negative correlation was found between amniotic fluid calprotectin and gestational age at delivery (rho = 0.32, p = 0.003). Relatively more bacteria in the amnio-chorionic niche were found in the sterile IAI group compared with the other groups.

CONCLUSIONS

Calprotectin concentrations in amniotic fluid were significantly higher in the intra-amniotic infection group compared with the other groups. Moreover, the bacterial presence in the amnio-chorionic niche was higher in IAI group.

Development of a Rat Model of Intra-Amniotic Inflammation via Ultrasound-Guided Administration of a Triggering Agent in the Gestational Sac to Enable Analysis of Individual Amniotic Fluid Samples

Objectives: To develop a rat model of intra-amniotic inflammation, characterized by the concentration of interleukin-6 in the amniotic fluid, induced by an ultrasound-guided transabdominal administration of lipopolysaccharide into individual gestational sacs.

Methods: An ultrasound-guided transabdominal intra-amniotic administration of lipopolysaccharide or phosphate-buffered saline (PBS) as control was performed in rats on embryonic day 18. Only accessible gestational sacs with precise recording of their positions were injected. Twenty-four hours later, individual amniotic fluid samples were collected from the gestational sacs of laparotomized animals. The gestational sacs were divided into four subgroups: (i) with lipopolysaccharide: injected gestational sacs from rats undergoing lipopolysaccharide administration; (ii) without lipopolysaccharide: non-injected gestational sacs from rats undergoing lipopolysaccharide administration; (iii) with PBS: injected gestational sacs from rats undergoing PBS administration; and (iv) without PBS: non-injected gestational sacs from rats undergoing PBS administration. The concentration of interleukin-6 in individual amniotic fluid samples was assessed using ELISA.

Results: In the group of five animals receiving lipopolysaccharide, 24 (33%) and 48 (77%) gestational sacs were and were not injected, respectively. The amniotic fluid was obtained from 21 (88%) injected and 46 (95%) non-injected sacs. In the control group of five animals receiving phosphate-buffered saline, 28 (35%) and 52 (75%) gestational sacs were and were not injected, respectively. The amniotic fluid was obtained from 18 (64%) injected and 50 (96%) non-injected sacs. No labor occurred, and only one fetal death was observed in a gestational sac injected with lipopolysaccharide. Differences in concentrations of interleukin-6 in the amniotic fluid were found among the subgroups of the gestational sacs (with lipopolysaccharide: median 762 pg/ml; without lipopolysaccharide: median 35.6 pg/ml; with PBS: median 35.6 pg/ml; and without PBS: median 35.6 pg/ml; p &lt; 0.0001). Concentrations of interleukin-6 in the amniotic fluid from the gestational sacs with lipopolysaccharide were significantly higher than those in the three remaining subgroups (p &lt; 0.0001). No differences in concentrations of interleukin-6 in the amniotic fluid were identified between the three remaining subgroups.

Conclusion: The ultrasound-guided transabdominal intra-amniotic administration of lipopolysaccharide with a subsequent collection and analysis of amniotic fluid samples is feasible in rats. The intra-amniotic administration of lipopolysaccharide led to the development of intra-amniotic inflammation without leading to fetal mortality or induction of labor.

Prevalence and Load of Cervical Ureaplasma Species With Respect to Intra-amniotic Complications in Women With Preterm Prelabor Rupture of Membranes Before 34 weeks

Objectives: To determine the prevalence and load of Ureaplasma spp. DNA in the cervical fluid of women with singleton pregnancies complicated by preterm prelabor rupture of membranes (PPROM) with respect to intra-amniotic infection, sterile intra-amniotic inflammation, and colonization of the amniotic fluid.

Methods: A total of 217 women with PPROM between gestational ages 24 + 0 and 33 + 6 weeks were included in this study. Paired amniotic and cervical fluid samples were collected at the time of admission via transabdominal amniocentesis and using a Dacron polyester swab, respectively. Microbial invasion of the amniotic cavity was diagnosed using a combination of culture and molecular biology methods. Intra-amniotic inflammation was determined based on the concentration of interleukin-6 in the amniotic fluid. Based on the presence or absence of these conditions, the women were stratified into the following subgroups: intra-amniotic infection (with both), sterile intra-amniotic inflammation (with inflammation only), colonization (with microorganisms only), and negative amniotic fluid (without either). The Ureaplasma spp. DNA load in the cervical fluid was assessed using PCR.

Results:Ureaplasma spp. DNA in the cervical fluid was found in 61% (133/217) of the women. Women with negative amniotic had similar prevalence of Ureaplasma spp. DNA in cervical fluid (55%) to those with sterile intra-amniotic inflammation (54%) but lower than those with intra-amniotic infection (73%) and colonization (86%; p < 0.0001). Women with negative amniotic fluid had a lower load of Ureaplasma spp. DNA in their cervical fluid (median: 4.7 × 10³ copies of DNA/ml) than those with intra-amniotic infection (median: 2.8 × 10⁵ copies DNA/ml), sterile intra-amniotic inflammation (median: 5.3 × 10⁴ copies DNA/ml), and colonization (median: 1.2 × 10⁵ copies DNA/mL; p < 0.0001).

Conclusion: In conclusion, in PPROM at <34 weeks, the presence of intra-amniotic infection, sterile intra-amniotic inflammation, or colonization of the amniotic fluid was associated with a higher prevalence and/or load of Ureaplasma spp. DNA in the cervical fluid than the absence of intra-amniotic complications.

Clinical characteristics of colonization of the amniotic cavity in women with preterm prelabor rupture of membranes, a retrospective study

To determine the main clinical characteristics of preterm prelabor rupture of membranes (PPROM) complicated by colonization of the amniotic cavity (microbial invasion of the amniotic cavity without intra-amniotic inflammation). A total of 302 women with PPROM were included. Transabdominal amniocentesis was performed and amniotic fluid was assessed. Based of microbial invasion of the amniotic cavity and intra-amniotic inflammation (interleukin-6 ≥ 3000 pg/mL), the women were divided into following groups: intra-amniotic infection, sterile intra-amniotic inflammation, colonization of the amniotic cavity, and negative amniotic fluid. Colonization was found in 11% (32/302) of the women. The most common bacteria identified in the amniotic fluid were Ureaplasma spp. with a lower burden than those with intra-amniotic infection (p = 0.03). The intensity of intra-amniotic inflammatory response measured by interleukin-6 was higher in women with colonization than in those with negative amniotic fluid (medians: 961 pg/mL vs. 616 pg/mL; p = 0.04). Women with colonization had higher rates of acute inflammatory placental lesions than those with negative amniotic fluid. In PPROM, colonization, caused mainly by microorganisms from the lower genital tract, might represent an early stage of microbial invasion of the amniotic cavity with a weak intra-amniotic inflammatory response.

Individualized treatment of preterm premature rupture of membranes to prolong the latency period, reduce the rate of preterm birth, and improve neonatal outcomes

BACKGROUND

Preterm premature rupture of membranes complicates approximately 3% of pregnancies. Currently, in the absence of chorioamnionitis or placental abruption, expectant management, including antenatal steroids for lung maturation and prophylactic antibiotic treatment, is recommended. The benefits of individualized management have not been adequately explored.

OBJECTIVE

This study aimed to compare the impact of 2 different management strategies of preterm premature rupture of membranes in 2 tertiary obstetrical centers on latency of >7 days, latency to birth, chorioamnionitis, funisitis, and short-term adverse maternal and neonatal outcomes.

STUDY DESIGN

This was a multicenter retrospective study of women with singleton pregnancies with preterm premature rupture of membranes from 23 0/7 to 33 6/7 weeks of gestation between 2014 and 2018 and undelivered within 24 hours after hospital admission managed at Sunnybrook Health Sciences Center, Toronto, Canada (standard management group), and BCNatal (Hospital Clínic of Barcelona and Hospital Sant Joan de Déu Barcelona), Barcelona, Spain (individualized management group), following local protocols. The standard management group received similar management for all patients, which included a standard antibiotic regimen and routine maternal and fetal surveillance, whereas the individualized management group received personalized management on the basis of amniocentesis at hospital admission (if possible), to rule out microbial invasion of the amniotic cavity and targeted treatment. The exclusion criteria were cervical dilatation >2 cm, active labor, contraindications to expectant management (acute chorioamnionitis, placental abruption, or abnormal fetal tracing), and major fetal anomalies. The primary outcome was latency of >7 days, and the secondary outcomes included latency to birth, chorioamnionitis, and short-term adverse maternal and neonatal outcomes. Statistical comparisons between groups were conducted with propensity score weighting.

RESULTS

A total of 513 pregnancies with preterm premature rupture of membranes were included in this study: 324 patients received standard management, and 189 patients received individualized management, wherein amniocentesis was performed in 112 cases (59.3%). After propensity score weighting, patients receiving individualized management had a higher latency of >7 days (76.0% vs 41.6%; P<.001) and latency to birth (18.1±14.7 vs 9.7±9.7 days; P<.001). Although a higher rate of clinical chorioamnionitis was suspected in the individualized management group than the standard group (34.5% vs 22.0%; P<.01), there was no difference between the groups in terms of histologic chorioamnionitis (67.2% vs 73.4%; P=.16), funisitis (57.6% vs 58.1%; P=.92), or composite infectious maternal outcomes (9.1% vs 7.9%; P=.64). Prolonged latency in the individualized management group was associated with a significant reduction of preterm birth at <32 weeks of gestation (72.1% vs 90.5%; P<.001), neonatal intensive care unit admission (75.6% vs 83.0%; P=.046), and neonatal respiratory support at 28 days of life (16.1% vs 26.1%; P<.01) compared with that in the standard management group. Moreover, prolonged latency was not associated with neonatal severe morbidity at discharge (survival without severe morbidity, 80.4% vs 73.5%; P=.09).

CONCLUSION

Individualized management of preterm premature rupture of membranes may prolong pregnancy and reduce preterm birth at <32 weeks of gestation, the need for neonatal support, and neonatal intensive care unit admissions, without an increase in histologic chorioamnionitis, funisitis, neonatal infection-related morbidity, and short-term adverse maternal and neonatal outcomes.

Acute Histological Chorioamnionitis and Birth Weight in Pregnancies With Preterm Prelabor Rupture of Membranes: A Retrospective Cohort Study

Aim: To assess the association between the birth weight of newborns from pregnancies with preterm prelabor rupture of membranes (PPROM) and the presence of acute histological chorioamnionitis (HCA) with respect to the: i) fetal and maternal inflammatory responses and ii) acute inflammation of the amnion.

Material and Methods: This retrospective cohort study included 818 women with PPROM. A histopathological examination of the placenta was performed. Fetal inflammatory response was defined as the presence of any neutrophils in umbilical cord (histological grades 1–4) and/or chorionic vasculitis (histological grade 4 for the chorionic plate). Maternal inflammatory response was defined as the presence of histological grade 3–4 for the chorion-decidua and/or grade 3 for the chorionic plate and/or grade 1–4 for the amnion. Acute inflammation of the amnion was defined as the presence of any neutrophils in the amnion (histological grade 1–4 for the amnion). Birth weights of newborns were expressed as percentiles derived from INTERGROWTH-21st standards for the i) estimated fetal weight and ii) newborn birth weight.

Results: No difference in percentiles of birth weights of newborns was found among the women with the women with HCA with fetal inflammatory response, with HCA with maternal inflammatory response and those without HCA. Women with HCA with acute inflammation of the amnion had lower percentiles of birth weights of newborns, derived from the estimated fetal weight standards, than women with HCA without acute inflammation of the amnion and those with the absence of HCA in the crude (with acute inflammation: median 46, without acute inflammation: median 52, the absence of HCA: median 55; p = 0.004) and adjusted (p = 0.02) analyses. The same subset of pregnancies exhibited the highest rate of newborns with a birth weight of ≤25 percentile. When percentiles were derived from the newborn weight standards, no differences in birth weights were observed among the subgroups.

Conclusion: Acute inflammation of the amnion was associated with a lower birth weight in PPROM pregnancies, expressed as percentiles derived from the estimated fetal weight standards.

Physiological TLR4 regulation in human fetal membranes as an explicative mechanism of a pathological preterm case

The integrity of human fetal membranes is crucial for harmonious fetal development throughout pregnancy. Their premature rupture is often the consequence of a physiological phenomenon that has been exacerbated. Beyond all the implied biological processes, inflammation is of primary importance and is qualified as ‘sterile’ at the end of pregnancy. In this study, complementary methylomic and transcriptomic strategies on amnion and choriodecidua explants obtained from the altered (cervix zone) and intact fetal membranes at term and before labour were used. By cross-analysing genome-wide studies strengthened by in vitro experiments, we deciphered how the expression of toll-like receptor 4 (TLR4), an actor in pathological fetal membrane rupture, is controlled. Indeed, it is differentially regulated in the altered zone and between both layers by a dual mechanism: (1) the methylation of TLR4 and miRNA promoters and (2) targeting by miRNA (let-7a-2 and miR-125b-1) acting on the 3’-UTR of TLR4. Consequently, this study demonstrates that fine regulation of TLR4 is required for sterile inflammation establishment at the end of pregnancy and that it may be dysregulated in the pathological premature rupture of membranes.

Birth weight and intra-amniotic inflammatory and infection-related complications in pregnancies with preterm prelabor rupture of membranes: a retrospective cohort study

OBJECTIVE

To assess the association between the birth weight of newborns and microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation in pregnancies with preterm prelabor rupture of membranes.

METHODS

A total of 528 pregnancies with preterm prelabor rupture of membranes were included in this retrospective cohort study. Transabdominal amniocentesis to determine the presence of MIAC (through culturing and molecular biology methods) and intra-amniotic inflammation (according to amniotic fluid interleukin-6 level) was performed as part of standard clinical management. Based on the presence of MIAC and/or intra-amniotic inflammation, the participants were divided into four subgroups: with intra-amniotic infection (presence of both), with sterile IAI (intra-amniotic inflammation alone), with colonization (MIAC alone), and with negative amniotic fluid (absence of both). Birth weights of newborns are expressed as percentiles derived from INTERGROWTH-21st standards for (i) newborn birth weight and (ii) estimated fetal weight.

RESULTS

No differences in birth weights, expressed as percentiles derived from newborn weight standards (infection: median 52; sterile: median 54; colonization: median 50; negative amniotic fluid: median 51; p = .93) and estimated fetal weight standards (infection: median 47; sterile: median 51; colonization: median 47; negative amniotic fluid: median 53; p = .48) were found among the four subgroups. No differences in percentiles (derived from both standards) were found in the subset of participants who delivered within 72 h after rupture of membranes (newborn weight standard, p = .99; estimated fetal weight standard, p = .81).

CONCLUSIONS

No association was identified between the birth weight of newborns and the presence of intra-amniotic inflammatory and infection-related complications in pregnancies with preterm prelabor rupture of membranes.

Intra-amniotic infection and sterile intra-amniotic inflammation in women with preterm labor with intact membranes are associated with a higher rate of Ureaplasma species DNA presence in the cervical fluid

OBJECTIVE

To determine the prevalence of Ureaplasma spp. DNA and its load in the cervical fluid in women with preterm labor with intact membranes (PTL) complicated by intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation) or sterile intra-amniotic inflammation (the presence of intra-amniotic inflammation alone).

METHODS

Overall, 115 women with singleton pregnancies complicated by PTL between gestational ages of 22 + 0 and 34 + 6 weeks were included in this study. Paired amniotic and cervical fluid samples were collected at the time of admission via transabdominal amniocentesis using a Dacron polyester swab. Microbial invasion of the amniotic cavity was diagnosed based on a combination of culture and molecular biology methods. Intra-amniotic inflammation was determined based on the concentration of interleukin-6 in the amniotic fluid. Bacterial and Ureaplasma spp. DNA loads were assessed in the cervical fluid using PCR.

RESULTS

Intra-amniotic infection and sterile inflammation were identified in 14% (16/115) and 25% (29/115) of the women, respectively. Ureaplasma spp. DNA in the cervical fluid was identified in 51% (59/115) of women. The presence of Ureaplasma spp. DNA in the cervical fluid was higher in women with intra-amniotic infection (75% (12/16)) and sterile intra-amniotic inflammation (76% (22/29)) than in women without intra-amniotic inflammation (36% (25/70); p = .0002). Concurrent presence of Ureaplasma spp. and Mycoplasma hominis DNA was higher in women with intra-amniotic infection (42% (5/12)) than women with sterile intra-amniotic inflammation (7% (2/29)) and women without intra-amniotic inflammation (7% (5/70); p = .001). There were no differences in the load of Ureaplasma spp. DNA in the cervical fluid among women with intra-amniotic infection, sterile intra-amniotic inflammation, and those without intra-amniotic inflammation (median values; infection: 1.2 × 10⁴ copies DNA/mL; sterile: 5.0 × 10⁵ copies DNA/mL; without: 8.4 × 10⁴ copies DNA/mL; p = .18).

CONCLUSIONS

In PTL , both forms of intra-amniotic inflammation were associated with a higher prevalence of Ureaplasma spp. DNA in the cervical fluid. The presence of intra-amniotic infection was related to a higher rate of concurrent Ureaplasma spp. and M. hominis DNA in the cervical fluid.

Presence of Chlamydia trachomatis DNA in the amniotic fluid in women with preterm prelabor rupture of membranes

OBJECTIVE

The primary aim of this study was to assess the rate and load of amniotic fluid Chlamydia trachomatis DNA and their associations with intra-amniotic infection and intra-uterine inflammatory complications in women with preterm prelabor rupture of membranes (PPROM). The secondary aim was to assess the short-term morbidity of newborns from PPROM pregnancies complicated by amniotic fluid C. trachomatis DNA.

METHODS

A retrospective study of 788 women with singleton pregnancies complicated by PPROM between 24 + 0 and 36 + 6 weeks of gestation was performed. Transabdominal amniocenteses were performed at the time of admission. C. trachomatis DNA in the amniotic fluid was assessed by real-time polymerase chain reaction using a commercial AmpliSens® C. trachomatis/Ureaplasma/Mycoplasma hominis-FRT kit, and the level of Ct DNA was quantified.

RESULTS

Amniotic fluid C. trachomatis DNA complicated 2% (16/788) of the PPROM pregnancies and was present in very low loads (median 57 copies DNA/mL). In addition to amniotic fluid C. trachomatis DNA, other bacteria were detected in 62% (10/16) of the C. trachomatis DNA-complicated PPROM pregnancies. Amniotic fluid C. trachomatis DNA was associated with intra-amniotic infection, histologic chorioamnionitis (HCA), and funisitis in 31%, 47%, and 33%, respectively. The presence of C. trachomatis DNA accompanied by Ureaplasma species in the amniotic fluid was associated with a higher rate of HCA than the presence of amniotic fluid C. trachomatis DNA alone. The composite neonatal morbidity in newborns from PPROM pregnancies with amniotic fluid C. trachomatis DNA was 31%.

CONCLUSION

The presence of C. trachomatis DNA in the amniotic fluid is a relatively rare condition in PPROM. Amniotic fluid C. trachomatis DNA in PPROM is not related to intensive intra-amniotic and intr-auterine inflammatory responses or adverse short-term neonatal outcomes.

Intra-amniotic inflammatory complications in preterm prelabor rupture of membranes and long-term neurodevelopmental outcomes of infants: a systematic review

OBJECTIVE

To perform a systematic review of the literature available on the association between the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation and long-term neurodevelopmental outcomes of infants from pregnancies complicated by preterm prelabor rupture of membranes (PPROM).

METHODS

A literature search, from their earliest entries to May 2020, was performed by employing three electronic databases (Web of Science, PubMed, and Scopus). The selection criteria were as follows: (1) singleton pregnancies with PPROM; (2) available information regarding MIAC and/or intra-amniotic inflammation; (3) long-term (at least one year of the corrected age) neurodevelopmental outcomes of respective infants.

RESULTS

The initial search identified 10,953 articles, of which 8 were selected for full-text reading; however, none were included in the review owing to the following reasons: (i) spontaneous preterm labor with intact membranes and/or indicated (iatrogenic) preterm delivery were included in the studies without providing separate data for PPROM (n = 5); (ii) long-term, at least one year of the corrected age, neurodevelopmental outcomes of infants were not assessed (n = 1); (iii) the presence of both the abovementioned reasons (n = 1); (iv) amniotic fluid was not assessed, and a long-term neurodevelopmental outcome was not evaluated (n = 1).

CONCLUSION

The literature search provides evidence of a knowledge gap in the association between the presence of MIAC and/or intra-amniotic inflammation and long-term neurodevelopmental outcomes in infants with PPROM.

IgGFc-binding protein in pregnancies complicated by spontaneous preterm delivery: a retrospective cohort study

To determine the IgGFc-binding protein (FcgammaBP) concentration in amniotic and cervical fluids in preterm prelabor rupture of membranes (PPROM) and preterm labor with intact membranes (PTL) and to assess the diagnostic indices of FcgammaBP to predict intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation). In this study, we included 170 and 79 women with PPROM and PTL, respectively. Paired cervical and amniotic fluid samples were obtained using a Dacron polyester swab and transabdominal amniocentesis, respectively. The FcgammaBP concentrations in the samples were assessed using an enzyme-linked immunosorbent assay. The presence of intra-amniotic infection was associated with elevated FcgammaBP concentrations in pregnancies with PPROM and PTL [PPROM—presence: 86 ng/mL vs. absence: 13 ng/mL, p < 0.0001, area under receiver operating characteristic curve (AUC) = 0.94; PTL—presence: 140 ng/mL vs. absence: 22 ng/mL, p < 0.0001, AUC = 0.86]. In cervical fluid, the concentrations of FcgammaBP were elevated in the presence of intra-amniotic infection in pregnancies with PPROM only (presence: 345 ng/mL vs. absence: 60 ng/mL, p < 0.0001, AUC = 0.93). FcgammaBP in amniotic fluid might be a marker of intra-amniotic infection in women with both PPROM and PTL However, in cervical fluid, it is only observed in women with PPROM.

Cervical Gardnerella vaginalis in women with preterm prelabor rupture of membranes

Objective

To determine the association between microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI) and the cervical prevalence of Gardnerella vaginalis DNA in pregnancies with preterm prelabor rupture of membrane (PPROM).

Method

In total, 405 women with singleton pregnancies complicated with PPROM were included. Cervical fluid and amniotic fluid samples were collected at the time of admission. Bacterial and G. vaginalis DNA were assessed in the cervical fluid samples using quantitative PCR technique. Concentrations of interleukin-6 and MIAC were evaluated in the amniotic fluid samples. Loads of G. vaginalis DNA ≥ 1% of the total cervical bacterial DNA were used to define the cervical prevalence of G. vaginalis as abundant. Based on the MIAC and IAI, women were categorized into four groups: with intra-amniotic infection (both MIAC and IAI), with sterile IAI (IAI without MIAC), with MIAC without IAI, and without either MIAC or IAI.

Results

The presence of the abundant cervical G. vaginalis was related to MIAC (with: 65% vs. without: 44%; p = 0.0004) but not IAI (with: 52% vs. without: 48%; p = 0.70). Women with MIAC without IAI had the highest load of the cervical G. vaginalis DNA (median 2.0 × 10⁴ copies DNA/mL) and the highest presence of abundant cervical G. vaginalis (73%).

Conclusions

In women with PPROM, the presence of cervical G. vaginalis was associated with MIAC, mainly without the concurrent presence of IAI.

Intra-amniotic infection and sterile intra-amniotic inflammation are associated with elevated concentrations of cervical fluid interleukin-6 in women with spontaneous preterm labor with intact membranes

OBJECTIVE

To determine the concentration of interleukin-6 (IL-6) in the cervical fluid in women with spontaneous preterm labor with intact fetal membranes (PTL) complicated by intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation), or sterile intra-amniotic inflammation (the presence of intra-amniotic inflammation alone).

METHODS

Eighty women with singleton pregnancies complicated by PTL between gestational ages 22 + 0 and 34 + 6 weeks were included in this retrospective cohort study. Samples of amniotic and cervical fluids were collected at the time of admission. Amniotic fluid samples were obtained via transabdominal amniocentesis, and cervical fluid was obtained using a Dacron polyester swab. Microbial invasion of the amniotic cavity was diagnosed based on the combination of culture and molecular biology methods. The concentration of IL-6 in the amniotic and cervical fluids were measured using an automated electrochemiluminescence immunoassay method. Intra-amniotic inflammation was defined as an amniotic fluid IL-6 concentration ≥3000 pg/mL.

RESULTS

The presence of intra-amniotic infection and sterile inflammation was identified in 15% (12/80) and 26% (21/80) of the women, respectively. Women with intra-amniotic infection (median: 587 pg/mL; p = .01) and with sterile intra-amniotic inflammation (median: 590 pg/mL; p = .005) had higher concentrations of IL-6 in the cervical fluid than those without intra-amniotic inflammation (intra-amniotic infection: median 587 pg/mL vs. without inflammation, median: 136 pg/mL; p = .01; sterile intra-amniotic inflammation, median: 590 pg/mL vs. without inflammation, p = .005). No differences were found in the concentrations of IL-6 in the cervical fluid between women with intra-amniotic infection and sterile intra-amniotic inflammation (p = .81).

CONCLUSION

In pregnancies with PTL, both forms of intra-amniotic inflammation are associated with elevated concentrations of IL-6 in the cervical fluid.

Intra-Amniotic Infection and Sterile Intra-Amniotic Inflammation in Cervical Insufficiency with Prolapsed Fetal Membranes: Clinical Implications

INTRODUCTION

The aim of this study was to identify the rates of 2 phenotypes of intra-amniotic inflammation: intra-amniotic infection (with microbial invasion of the amniotic cavity [MIAC]) and sterile intra-amniotic inflammation (without MIAC), and their outcomes, among women with cervical insufficiency with prolapsed fetal membranes.

METHODS OF STUDY

This is a retrospective study of women admitted to the Department of Obstetrics and Gynecology, University Hospital Hradec Kralove between January 2014 and May 2020. Transabdominal amniocentesis to evaluate intra-amniotic inflammation (amniotic fluid interleukin-6) and MIAC (culturing and molecular biology methods) was performed as part of standard clinical management.

RESULTS

In total, 37 women with cervical insufficiency and prolapsed fetal membranes were included; 11% (4/37) and 43% (16/37) of them had intra-amniotic infection and sterile intra-amniotic inflammation, respectively. In women with intra-amniotic infection and sterile intra-amniotic inflammation, we noted shorter intervals between admission and delivery (both p < 0.0001), and lower gestational age at delivery (p < 0.0001 and p = 0.004) and percentiles of birth/abortion weight (p = 0.03 and p = 0.009, respectively) than in those without intra-amniotic inflammation.

CONCLUSIONS

Both phenotypes of intra-amniotic inflammation, with sterile intra-amniotic inflammation being more frequent, are associated with worse outcomes in pregnancies with cervical insufficiency with prolapsed fetal membranes.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comprehensive proteomic investigation of infectious and inflammatory changes in late preterm prelabour rupture of membranes

Preterm prelabour rupture of membranes beyond the 34th week of gestation (late PPROM) is frequently associated with the risk of the microbial invasion of the amniotic fluid (MIAC) and histological chorioamnionitis (HCA). Hence, we employed a Tandem Mass Tag-based approach to uncover amniotic fluid proteome response to the presence of MIAC and HCA in late PPROM. Protein dysregulation was associated with only five cases in the group of 15 women with confirmed MIAC and HCA. Altogether, 138 amniotic fluid proteins were changed in these five cases exclusively. These proteins were particularly associated with excessive neutrophil responses to infection, such as neutrophil degranulation and extracellular trap formation. We believe that the quantification of these proteins in amniotic fluid may assist in revealing women with the highest risk of excessive inflammatory response in late PPROM.

Extracellular granzyme A in amniotic fluid is elevated in the presence of sterile intra-amniotic inflammation in preterm prelabor rupture of membranes

INTRODUCTION

To determine the levels of granzyme A in amniotic fluid in pregnancies complicated by preterm prelabor rupture of membranes (PPROM), based on the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI).

METHODS OF STUDY

A total of 166 women with singleton pregnancies complicated by PPROM were included. Amniocentesis was performed at the time of admission and assessments of MIAC (using both cultivation and non-cultivation techniques) and IAI (interleukin-6 in amniotic fluid) were performed on all subjects. Based on the presence/absence of MIAC and IAI, the women were further divided into the following subgroups: intra-amniotic infection, sterile IAI, colonization, and absence of both MIAC and IAI. Amniotic fluid granzyme A levels were assessed using ELISA.

RESULTS

Women with MIAC had lower levels of granzyme A in the amniotic fluid than women without this condition (with MIAC: median 15.9 pg/mL vs. without MIAC: median 19.9 pg/mL, p = .03). Women with sterile IAI had higher amniotic fluid granzyme A levels than women with intra-amniotic infection, colonization and women with the absence of either MIAC or IAI (intra-amniotic infection: median 15.6 pg/mL; sterile IAI: median 31.8 pg/mL; colonization: median 16.9 pg/mL; absence of both MIAC and IAI: median 18.8 pg/mL; p = .02).

CONCLUSIONS

The presence of sterile IAI was associated with elevated levels of granzyme A in amniotic fluid.

A new rapid bedside test to diagnose and monitor intraamniotic inflammation in preterm PROM using transcervically collected fluid

BACKGROUND

Microbial invasion of the amniotic cavity, a clinical condition present in approximately 50% of patients with preterm prelabor rupture of membranes, is often associated with intraamniotic inflammation, a risk factor for a short admission-to-delivery interval, early preterm delivery, and neonatal complications. We previously developed a transcervical amniotic fluid collector, the device that allows the collection of fluid noninvasively from the cervical canal when membrane rupture occurs.

OBJECTIVE

This study was designed to determine whether rapid analysis of an interleukin-8 concentration in fluid obtained noninvasively by the transcervical amniotic fluid collector can be used to assess the risk of intraamniotic inflammation. We also compared the diagnostic performance of this point-of-care test for interleukin-8 in transcervically obtained fluid to that of a white blood cell count determined in amniotic fluid retrieved by transabdominal amniocentesis.

STUDY DESIGN

This prospective cohort study was conducted between October 2011 and April 2017. Fluid was retrieved through both transabdominal amniocentesis and the use of a transcervical amniotic fluid collector within 24 hours of amniocentesis in patients with a singleton pregnancy and preterm prelabor rupture of the membranes (16-35 weeks of gestation). Amniotic fluid obtained via amniocentesis was cultured for aerobic and anaerobic bacteria and genital mycoplasmas; a white blood cell count was also measured in amniotic fluid. Intraamniotic infection was diagnosed when microorganisms were identified by the cultivation of amniotic fluid. Intraamniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL) assayed by enzyme-linked immunosorbent assay. Interleukin-8 in cervical fluid obtained by the collector was measured by the point-of-care test that used a test strip and scanner based on the fluorescence immunochromatographic analysis in 2019. The diagnostic indices, predictive values, and likelihood ratios of the 2 different tests were calculated.

RESULTS

First, interleukin-8 concentration ≥9.5 ng/mL in cervical fluid, determined by the point-of-care test, was at the knee of the receiver operating characteristic curve analysis and had a sensitivity of 98% (56/57; 95% confidence interval, 91-99.96%), specificity of 74% (40/54; 95% confidence interval, 60-85%), positive predictive value of 80% (56/70; 95% confidence interval, 72-86%), negative predictive value of 98% (40/41; 95% confidence interval, 85-99.6%), positive likelihood ratio of 3.79 (95% confidence interval, 2.41-5.96), and negative likelihood ratio of 0.02 (95% confidence interval, 0.003-0.17) in the identification of intraamniotic inflammation; a concentration of matrix metalloproteinase-8 >23 ng/mL by enzyme-linked immunosorbent assay had a prevalence of 51% (57/111). Second, a cervical fluid interleukin-8 concentration ≥9.5 ng/mL had significantly higher sensitivity than a transabdominally obtained amniotic fluid white blood cell count (≥19 cells/mm³) in the identification of intraamniotic inflammation (sensitivity: 98% [95% confidence interval, 91-99.96%] vs 84% [95% confidence interval, 72-93%]; P<.05; specificity: 74% [95% confidence interval, 60-85%] vs 76% [95% confidence interval, 62-87%); positive and negative predictive values: 80% [95% confidence interval, 72-86%] and 98% [95% confidence interval, 85-99.6%] vs 79% [95% confidence interval, 69-86%] and 82% [95% confidence interval, 71-89%]) and in the identification of intraamniotic inflammation/infection (gold standard: positive culture for bacteria or a matrix metalloproteinase-8 >23 ng/mL; sensitivity: 91% [95% confidence interval, 82-97%] vs 75% [95% confidence interval, 63-85%]; P<.05).

CONCLUSION

The point-of-care test was predictive of intraamniotic inflammation, based on the determination of interleukin-8 in fluid retrieved by a transcervical amniotic fluid collector. Therefore, the analysis of cervically obtained fluid by such point-of-care test may be used to noninvasively monitor intraamniotic inflammation in patients with preterm prelabor rupture of membranes.

Maternal risk score for the prediction of fetal inflammatory response syndrome after preterm premature rupture of membranes

AIM

Preterm premature rupture of membranes (PPROM) is common in preterm births. Fetal inflammatory response syndrome (FIRS) is present in nearly 50% of PPROM cases. We created a risk score to predict FIRS using maternal factors after PPROM.

METHODS

We conducted a retrospective study of singleton pregnancies complicated by PPROM that resulted in delivery at 23-35 weeks of gestation. Antepartum maternal factors and umbilical cord blood interleukin-6 (IL-6) data were analyzed. FIRS was defined as IL-6 > 11 pg/mL.

RESULTS

Umbilical cord blood IL-6 and maternal blood data within 24 h before parturition were available for 158 cases; 66 were diagnosed with FIRS (41.8%; median IL-6, 57.55 pg/mL). We created a risk score (FIRS score) comprising expected delivery weeks (≤30 weeks), maternal C-reactive protein (≥1.2 mg/dL), maternal white blood cell count (≥13 000/μL), corticosteroid use (none) and PROM latency period (≥3 days) from the multivariate logistic regression model predicting FIRS. Receiver operating characteristic curve analysis of the score produced the following results: area under the curve, 0.82; 95% CI, 0.76-0.89; cut-off value, 7.5; sensitivity, 89%; specificity, 63%; positive predictive value, 63% and negative predictive value, 89%. The probability of FIRS according to the categories of the FIRS score was 11% for those with a score of 0-7, 50% for a score of 8-15, and 88% for a score of 16-22.

CONCLUSION

The devised maternal risk score could predict FIRS and be helpful to decide the delivery timing for the cases of PPROM.

Interleukin (IL)-6: A Friend or Foe of Pregnancy and Parturition? Evidence From Functional Studies in Fetal Membrane Cells

Objective

Protection of the fetus within the amniotic sac is primarily attained by remodeling fetal membrane (amniochorion) cells through cyclic epithelial to mesenchymal and mesenchymal to epithelial (EMT and MET) transitions. Endocrine and paracrine factors regulate EMT and MET during pregnancy. At term, increased oxidative stress forces a terminal state of EMT and inflammation, predisposing to membrane weakening and rupture. IL-6 is a constitutively expressed cytokine during gestation, but it is elevated in term and preterm births. Therefore, we tested the hypothesis that IL-6 can determine the fate of amnion membrane cells and that pathologic levels of IL-6 can cause a terminal state of EMT and inflammation, leading to adverse pregnancy outcomes.

Methods

Primary amnion epithelial cells (AECs) were treated with recombinant IL-6 (330, 1,650, 3,330, and 16,000 pg/ml) for 48 h (N = 5). IL-6-induced cell senescence (aging), cell death (apoptosis and necrosis), and cell cycle changes were studied using flow cytometry. Cellular transitions were determined by immunocytochemistry and western blot analysis, while IL-6 signaling (activation of signaling kinases) was measured by immunoassay. Inflammatory marker matrix metalloproteinase (MMP9) and granulocyte-macrophage colony-stimulating factor (GM-CSF) concentrations were measured using a Fluorokine E assay and ELISA, respectively. Amniotic membranes collected on gestational day (D) 12 and D18 from IL-6 knockout (KO) and control C57BL/6 mice (N = 3 each) were used to determine the impact of IL-6 on cell transitions. Fold changes were measured based on the mean of each group.

Results

IL-6 treatment of AECs at physiologic or pathologic doses increased JNK and p38MAPK activation; however, the activation of signals did not cause changes in AEC cell cycle, cellular senescence, apoptosis, necrosis, cellular transitions, or inflammation (MMP9 and GM-CSF) compared to control. EMT markers were higher on D18 compared to D12 regardless of IL-6 status in the mouse amniotic sac.

Conclusion

Physiologic and pathologic concentrations of IL-6 did not cause amnion cell aging, cell death, cellular transitions, or inflammation. IL-6 may function to maintain cellular homeostasis throughout gestation in fetal membrane cells. Although IL-6 is a good biomarker for adverse pregnancies, it is not an indicator of an underlying pathological mechanism in membrane cells.

Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes

BACKGROUND

Preterm prelabor rupture of the membranes (PPROM) is frequently complicated by intraamniotic inflammatory processes such as intraamniotic infection and sterile intraamniotic inflammation. Antibiotic therapy is recommended to patients with PPROM to prolong the interval between this complication and delivery (latency period), reduce the risk of clinical chorioamnionitis, and improve neonatal outcome. However, there is a lack of information regarding whether the administration of antibiotics can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with PPROM.

OBJECTIVE

The first aim of the study was to determine whether antimicrobial agents can reduce the magnitude of the intraamniotic inflammatory response in patients with PPROM by assessing the concentrations of interleukin-6 in amniotic fluid before and after antibiotic treatment. The second aim was to determine whether treatment with intravenous clarithromycin changes the microbial load of Ureaplasma spp DNA in amniotic fluid.

STUDY DESIGN

A retrospective cohort study included patients who had (1) a singleton gestation, (2) PPROM between 24+0 and 33+6 weeks, (3) a transabdominal amniocentesis at the time of admission, and (4) intravenous antibiotic treatment (clarithromycin for patients with intraamniotic inflammation and benzylpenicillin/clindamycin in the cases of allergy in patients without intraamniotic inflammation) for 7 days. Follow-up amniocenteses (7^th day after admission) were performed in the subset of patients with a latency period lasting longer than 7 days. Concentrations of interleukin-6 were measured in the samples of amniotic fluid with a bedside test, and the presence of microbial invasion of the amniotic cavity was assessed with culture and molecular microbiological methods. Intraamniotic inflammation was defined as a bedside interleukin-6 concentration ≥745 pg/mL in the samples of amniotic fluid. Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presence of intraamniotic inflammation without microbial invasion of the amniotic cavity.

RESULTS

A total of 270 patients with PPROM were included in this study: 207 patients delivered within 7 days and 63 patients delivered after 7 days of admission. Of the 63 patients who delivered after 7 days following the initial amniocentesis, 40 underwent a follow-up amniocentesis. Patients with intraamniotic infection (n = 7) and sterile intraamniotic inflammation (n = 7) were treated with intravenous clarithromycin. Patients without either microbial invasion of the amniotic cavity or intraamniotic inflammation (n = 26) were treated with benzylpenicillin or clindamycin. Treatment with clarithromycin decreased the interleukin-6 concentration in amniotic fluid at the follow-up amniocentesis compared to the initial amniocentesis in patients with intraamniotic infection (follow-up: median, 295 pg/mL, interquartile range [IQR], 72-673 vs initial: median, 2973 pg/mL, IQR, 1750-6296; P = .02) and in those with sterile intraamniotic inflammation (follow-up: median, 221 pg/mL, IQR 118-366 pg/mL vs initial: median, 1446 pg/mL, IQR, 1300-2941; P = .02). Samples of amniotic fluid with Ureaplasma spp DNA had a lower microbial load at the time of follow-up amniocentesis compared to the initial amniocentesis (follow-up: median, 1.8 × 10⁴ copies DNA/mL, 2.9 × 10⁴ to 6.7 × 10⁸ vs initial: median, 4.7 × 10⁷ copies DNA/mL, interquartile range, 2.9 × 10³ to 3.6 × 10⁷; P = .03).

CONCLUSION

Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation. Moreover, treatment with clarithromycin was related to a reduction in the load of Ureaplasma spp DNA in the amniotic fluid of patients with PPROM <34 weeks of gestation.

Amniotic fluid glucose level in PPROM pregnancies: a glance at the old friend

Introduction: To determine the amniotic fluid glucose levels in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) based on the presence of microbial invasion of the amniotic cavity and/or intra-amniotic inflammation.Methods of Study: A total of 142 women with singleton pregnancies complicated by PPROM between gestational ages 24 + 0 and 36 + 6 weeks were included. Amniocentesis was performed at the time of admission. The assessments of microbial invasion of the amniotic cavity (using both cultivation and non-cultivation techniques) and intra-amniotic inflammation (amniotic fluid interleukin-6 levels ≥ 3000 pg/mL) were performed on all the women. Based on the presence of microbial invasion of the amniotic cavity and/or intra-amniotic inflammation, the women were further categorized into the subgroups: (i) intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation); (ii) sterile intra-amniotic inflammation (the presence of intra-amniotic inflammation without microbial invasion of the amniotic cavity); (iii) colonization (the presence of microbial invasion of the amniotic cavity without intra-amniotic inflammation); and (iv) negative amniotic fluid (the absence of either microbial invasion of the amniotic cavity or intra-amniotic inflammation). Amniotic fluid glucose levels were assessed using enzymatic reference method with hexokinase.Results: There was a difference in the amniotic fluid glucose levels among the women with intra-amniotic infection, sterile intra-amniotic inflammation, colonization, and those with negative amniotic fluid (p < .0001). No difference was found in the amniotic fluid glucose levels between women with intra-amniotic infection and those with sterile intra-amniotic inflammation [infection: median 11.6 mg/dL (0.7 mmol/L) vs. sterile: median 6.3 mg/dL (0.4 mmol/L); p = .41] and between women with colonization and negative amniotic fluid [colonization: median 21.6 mg/dL (1.2 mmol/L) vs. negative: median 23.4 mg/dL (1.3 mmol/L; p = .67]. Women with intra-amniotic infection and sterile intra-amniotic inflammation had lower amniotic fluid glucose levels than women with colonization and with negative amniotic fluid in crude analysis as well as after adjustment for gestational age at sampling. Amniotic fluid glucose level of 10 mg/dL (0.56 mmol/L) was the optimal concentration for the identification of intra-amniotic inflammation in women with PPROM.Conclusions: The presence of intra-amniotic inflammation was associated with lower amniotic fluid glucose levels in singleton pregnancies complicated with PPROM. An amniotic fluid glucose level of 10 mg/dL (0.56 mmol/L) was the optimal concentration for the identification of intra-amniotic inflammation in PPROM pregnancies. In the absence of better amniotic fluid markers, amniotic glucose could be used as a marker of intra-amniotic inflammation, with very good specificity in PPROM pregnancies.

A rodent model of intra-amniotic inflammation/infection, induced by the administration of inflammatory agent in a gestational sac, associated with preterm delivery: a systematic review

Background: Rodents are the most commonly used animals in the study of spontaneous preterm delivery (PTD). Intra-amniotic inflammation/infection is a frequent and important cause of PTD. Intraperitoneal and intrauterine administrations of inflammatory agents are traditional methods to establish a rodent model of PTD associated with inflammation and infection. The intra-amniotic administration of inflammatory or infectious triggering agents to rodents can be useful to study not only intra-amniotic inflammatory response but also PTD associated with intra-amniotic inflammation/infection.Objective: This systematic review aimed mainly to assess and analyze all described methods of intra-amniotic administration of infectious and/or inflammatory agents to create a rodent model of intra-amniotic inflammation associated with PTD.Methods: A literature search through two electronic databases from their earliest entries to February 2019 was performed. The selection criteria were as follows: (1) rodents as model animals, (2) a model of intra-amniotic inflammation/infection associated with PTD, and (3) intra-amniotic administration of triggering agents. Data extraction included specification of the study (author and year of publication), characteristics of study animals (species, strain, and number of animals), characteristics of intervention (timing and used technique), substance used for induction of intra-amniotic inflammation/infection, and outcome assessment.Results: The search identified a total of 4673 articles, of which 118 were selected for full-text reading, but only 13 studies were included in the review. Intra-amniotic administration was used only in the articles that were published beyond 2004. Two different approaches were identified: (1) open surgery with direct puncture of the amniotic sacs and (2) transabdominal ultrasound-guided puncture of the gestational sacs. Live microorganisms (Ureaplasma parvum), bacterial products (extracellular membrane vesicles), and pathogen-associated (lipopolysaccharide) and damage-associated molecular patterns (high mobility group box-1, S100B, and surfactant protein A) were used to simulate intra-amniotic inflammation/infection. Differences in the effect on intra-amniotic inflammation/infection associated with PTD in the mouse model were identified among triggering agents. Intra-amniotic application of lipopolysaccharide in the rat model caused intra-amniotic inflammation, but it did not lead to PTD.Conclusion: The intra-amniotic administration of the triggering agents can be used to study intra-amniotic inflammatory response and intra-amniotic inflammation/infection in the rodents model.

Lactobacilli-dominated cervical microbiota in women with preterm prelabor rupture of membranes

BACKGROUND

To determine the association between microbial invasion of the amniotic cavity (MIAC) and the presence of Lactobacillus crispatus- or Lactobacillus iners-dominated cervical microbiota in pregnancies with preterm prelabor rupture of membrane. Next, to assess the relationship between the presence of L. crispatus- or L. iners-dominated cervical microbiota and short-term neonatal morbidity.

METHOD

A total of 311 women were included. Cervical samples were obtained using a Dacron polyester swab and amniotic fluid samples were obtained by transabdominal amniocentesis. Bacterial DNA, L. crispatus, and L. iners in the cervical samples were assessed by PCR. Cervical microbiota was assigned as L. crispatus- or L. iners-dominated when the relative abundance of L. crispatus or L. iners was ≥50% of the whole cervical microbiota, respectively.

RESULTS

Women with MIAC showed a lower rate of L. crispatus-dominated cervical microbiota (21% vs. 39%; p = 0.003) than those without MIAC. Lactobacillus crispatus-dominated cervical microbiota was associated with a lower rate of early-onset sepsis (0% vs. 5%; p = 0.02).

CONCLUSIONS

The presence of L. crispatus-dominated cervical microbiota in women with preterm prelabor rupture of membrane was associated with a lower risk of intra-amniotic complications and subsequent development of early-onset sepsis of newborns.

Cellular immune responses in amniotic fluid of women with preterm prelabor rupture of membranes

Background Preterm birth is the leading cause of perinatal morbidity and mortality. Preterm prelabor rupture of membranes (pPROM) occurs in 30% of preterm births; thus, this complication is a major contributor to maternal and neonatal morbidity. However, the cellular immune responses in amniotic fluid of women with pPROM have not been investigated. Methods Amniotic fluid samples were obtained from women with pPROM and a positive (n = 7) or negative (n = 10) microbiological culture. Flow cytometry was performed to evaluate the phenotype and number of amniotic fluid leukocytes. The correlation between amniotic fluid immune cells and an interleukin-6 (IL-6) concentration or a white blood cell (WBC) count in amniotic fluid was calculated. Results Women with pPROM and a positive amniotic fluid culture had (1) a greater number of total leukocytes in amniotic fluid, including neutrophils and monocytes/macrophages and (2) an increased number of total T cells in amniotic fluid, namely CD4+ T cells and CD8+ T cells, but not B cells. The numbers of neutrophils and monocytes/macrophages were positively correlated with IL-6 concentrations and WBC counts in amniotic fluid of women with pPROM. Conclusion Women with pPROM and a positive amniotic fluid culture exhibit a more severe cellular immune response than those with a negative culture, which is associated with well-known markers of intra-amniotic inflammation.

Value of cervicovaginal fluid cytokines in prediction of fetal inflammatory response syndrome in pregnancies complicated with preterm premature rupture of membranes (pPROM)

Background Preterm premature rupture of membranes (pPROM) is associated with a high risk of prematurity and complications of fetal inflammatory response syndrome (FIRS). The aim of the study is to determine any correlations between the concentration of selected cytokines contained in the cervicovaginal secretion eluates and in the umbilical cord plasma in patients with pPROM and to find the noninvasive markers of FIRS in order to pinpoint the optimal time of the delivery. Methods The study included 80 patients with pPROM between the 24th and 34th week of gestation. The cervicovaginal fluid and umbilical cord blood were collected. Interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 19 (IL-19) and tumor necrosis factor-α (TNF-α) concentrations were measured in both materials. For the statistical analysis, SigmaStat3.5 software was used. Results There was no direct association in levels of IL-6, TNF-α, IL-10 and IL-19 between the cord blood and cervicovaginal secretions within the studied group. The cut-off point of IL-6 of 26.8 pg/mL in the vaginal fluid had high sensitivity and specificity in order to discriminate between newborns with and without FIRS (81.08%; 76.74%). Conclusion Further studies are needed on a larger group of participants to demonstrate that an elevated concentration of IL-6 above 26.8 pg/mL in the cervicovaginal secretion eluate is an indirect noninvasive marker of FIRS.

Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Background Intra-amniotic inflammation, which is associated with adverse pregnancy outcomes, can occur in the presence or absence of detectable microorganisms, and involves activation of the inflammasome. Intra-amniotic inflammasome activation has been reported in clinical chorioamnionitis at term and preterm labor with intact membranes, but it has not yet been investigated in women with preterm prelabor rupture of membranes (preterm PROM) in the presence/absence of detectable microorganisms. The aim of this study was to determine whether, among women with preterm PROM, there is an association between detectable microorganisms in amniotic fluid and intra-amniotic inflammation, and whether intra-amniotic inflammasome activation correlates with microbial burden. Methods Amniotic fluids from 59 cases of preterm PROM were examined for the presence/absence of microorganisms through culture and 16S ribosomal RNA (rRNA) gene quantitative real-time polymerase chain reaction (qPCR), and concentrations of interleukin-6 (IL-6) and ASC [apoptosis-associated spec-like protein containing a caspase recruitment domain (CARD)], an indicator of inflammasome activation, were determined. Results qPCR identified more microbe-positive amniotic fluids than culture. Greater than 50% of patients with a negative culture and high IL-6 concentration in amniotic fluid yielded a positive qPCR signal. ASC concentrations were greatest in patients with high qPCR signals and elevated IL-6 concentrations in amniotic fluid (i.e. intra-amniotic infection). ASC concentrations tended to increase in patients without detectable microorganisms but yet with elevated IL-6 concentrations (i.e. sterile intra-amniotic inflammation) compared to those without intra-amniotic inflammation. Conclusion qPCR is a valuable complement to microbiological culture for the detection of microorganisms in the amniotic cavity in women with preterm PROM, and microbial burden is associated with the severity of intra-amniotic inflammatory response, including inflammasome activation.

Fetal membrane bacterial load is increased in histologically confirmed inflammatory chorioamnionitis: A retrospective cohort study

INTRODUCTION

It is widely debated whether fetal membranes possess a genuine microbiome, and if bacterial presence and load is linked to inflammation. Chorioamnionitis is an inflammation of the fetal membranes. This research focussed on inflammatory diagnosed histological chorioamnionitis (HCA) and aimed to determine whether the bacterial load in fetal membranes correlates to inflammatory response, including histological staging and inflammatory markers in HCA.

METHODS

Fetal membrane samples were collected from patients with preterm spontaneous labour and histologically phenotyped chorioamnionitis (HCA; n = 12), or preterm (n = 6) and term labour without HCA (n = 6). The bacterial profile of fetal membranes was analysed by sequencing the V4 region of the 16S rRNA gene. Bacterial load was determined using qPCR copy number/mg of tissue. The association between bacterial load and bacterial profile composition was assessed using correlation analysis.

RESULTS

Bacterial load was significantly greater within HCA amnion (p = 0.002) and chorion (p = 0.042), compared to preterm birth without HCA. Increased bacterial load was positively correlated with increased histological staging (p = 0.001) and the expression of five inflammatory markers; IL8, TLR1, TLR2, LY96 and IRAK2 (p=<0.050). Bacterial profiles were significantly different between membranes with and without HCA in amnion (p = 0.012) and chorion (p = 0.001), but no differences between specific genera were detected.

DISCUSSION

Inflammatory HCA is associated with infection and increased bacterial load in a dose response relationship. Bacterial load is positively correlated with HCA severity and the TLR signalling pathway. Further research should investigate the bacterial load threshold required to generate an inflammatory response in HCA.

Nicotinamide phosphoribosyltransferase and intra-amniotic inflammation in preterm prelabor rupture of membranes

Introduction: The amniotic fluid nicotinamide phosphoribosyltransferase (NAMPT) levels have not been compared among women with preterm prelabor rupture of membranes (PPROM) comorbid with intra-amniotic infection, sterile intra-amniotic inflammation (IAI), colonization, or without IAI and microbial invasion of the amniotic cavity (MIAC). Therefore, the main aim was to quantify the amniotic fluid NAMPT in women with PPROM complicated by intra-amniotic infection, sterile IAI, or colonization. The second aim was to characterize the diagnostic indices of NAMPT to reveal IAI. The third aim was to determine whether the cervical fluid and maternal serum NAMPT quantitation might be of value in the identification of intra-amniotic inflammatory complications in PPROM.Methods of study: NAMPT levels in amniotic fluid, cervical fluid, and maternal serum were assessed in three independent cohorts of women with singleton pregnancies complicated by PPROM between 24⁺⁰ and 36⁺⁶ weeks of gestation consisting of 88, 121, and 88 women, respectively. Amniotic fluid samples were obtained by transabdominal amniocentesis, cervical fluid samples were obtained using a Dacron polyester swab and maternal blood was obtained by venipuncture of the cubital vein. The NAMPT levels were measured by an enzyme-linked immunosorbent assay. Testing for MIAC and IAI was performed on all women, who were then categorized into four subgroups: intra-amniotic infection (MIAC and IAI), sterile IAI (IAI alone), colonization (MIAC alone), and without MIAC and IAI.Results: Women with intra-amniotic infection and women with sterile IAI had higher NAMPT levels than did women with colonization and women without MIAC and IAI (intra-amniotic infection: median 73.6 ng/mL, sterile IAI: median 55.5 ng/mL, colonization: median 12.1 ng/mL, without MIAC and IAI: 10.6 ng/mL; p < .0001). An amniotic fluid NAMPT level of 37 ng/mL was the best value for the detection of intra-amniotic infection in women with PPROM. Cervical fluid (p = .51) and maternal serum (p = .50) NAMPT levels did not reflect intra-amniotic inflammatory complications in women with PPROM.Conclusions: Intra-amniotic infection and sterile IAI are associated with higher NAMPT levels in amniotic fluid but not in cervical fluid or maternal serum in women with PPROM. Amniotic fluid NAMPT might be a marker for invasive identification of IAI in PPROM.

Fetal Portal System Flowmetry and Intra-Amniotic Inflammation in Preterm Prelabor Rupture of Membranes

OBJECTIVES

To determine the pulsatility index (PI) in the fetal splenic vein, the main portal vein, the left portal vein, and the ductus venosus with respect to the presence or absence of intra-amniotic inflammation (IAI) in preterm prelabor rupture of membranes (PPROM).

METHOD

Women with singleton pregnancies and PPROM, ranging in gestational age from 22+0 to 36+6 weeks, were included. Amniotic fluid samples were obtained by transabdominal amniocentesis and the amniotic fluid level of interleukin-6 (IL-6) was assessed by a point-of-care test. Doppler examination of the selected veins was performed, and the PI was assessed. IAI was defined as amniotic fluid levels of IL-6 ≥745 pg/mL.

RESULTS

In total, 42 women were included. Fetuses with IAI compared with those without IAI exhibited a higher PI in the splenic vein (p = 0.005) and the main portal vein (p = 0.05). No differences were observed in the left portal vein PI (p = 0.36) and the ductus venosus PI (p = 0.98).

CONCLUSION

IAI was associated with increased fetal splenic vein PI and main portal vein PI in PPROM. The absence of changes in the left portal vein PI and ductus venosus PI supports the local cause of the finding.

Interleukin-6 measured using the automated electrochemiluminescence immunoassay method for the identification of intra-amniotic inflammation in preterm prelabor rupture of membranes

Introduction: We aimed to compare the amniotic fluid interleukin (IL)-6 concentrations measured using the automated electrochemiluminescence immunoassay method and ELISA, and to establish an IL-6 concentration cut-off value for intra-amniotic inflammation (IAI) in preterm prelabor rupture of membranes (PPROM), which can be used in the automated electrochemiluminescence immunoassay method.Materials and methods: A total of 120 women with PPROM were included in this study. Amniotic fluid samples were obtained through transabdominal amniocentesis. IL-6 concentrations were assessed using both the automated electrochemiluminescence immunoassay method and ELISA, the current gold standard. IAI was defined as an amniotic fluid IL-6 concentration of ≥2600 pg/mL measured using ELISA.Results: A correlation between both assays was found (Spearman's rho = 0.97; p < .0001). Based on the receiver-operating characteristic curve for the identification of IAI (area under the curve = 0.99), a cut-off value of ≥3000 pg/mL was selected for the automated electrochemiluminescence immunoassay method with a sensitivity of 88%, specificity of 99%, positive predictive value of 97%, negative predictive value of 96%, and likelihood ratio of 76.Conclusions: For amniotic fluid IL-6 concentrations assessed using the automated electrochemiluminescence immunoassay method, a cut-off value of 3000 pg/mL was indicated for diagnosing IAI in women with PPROM.

Amniotic fluid cell-free DNA in preterm prelabor rupture of membranes

INTRODUCTION

We evaluated the levels of cell-free nuclear DNA (nDNA) and cell-free mitochondrial DNA (mtDNA) in the amniotic fluid supernatant from pregnancies complicated by preterm prelabor rupture of membranes (PPROM) based on evidence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI).

MATERIAL AND METHODS

A total of 155 women with PPROM were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis. The levels of cell-free nDNA and mtDNA in the amniotic fluid supernatant were assessed and quantified by real-time polymerase chain reaction.

RESULTS

The levels of cell-free nDNA and mtDNA were higher in women with MIAC and IAI than in women without these conditions (nDNA: with MIAC: median 3.9 × 10⁴ genome equivalent [GE]/mL vs without MIAC: median 1.2 × 10⁴  GE/mL, with IAI: median: 5.3 × 10⁴  GE/mL vs without IAI: median 1.2 × 10⁴  GE/mL; mtDNA: with MIAC: median 9.2 × 10⁵  GE/mL vs without MIAC: median 2.5 × 10⁵  GE/mL, with IAI: median 1.1 × 10⁶  GE/mL vs without IAI: median 2.5 × 10⁵ ; all P values ≤ 0.01). Women with the microbial-associated IAI showed the highest levels of cell-free nDNA and mtDNA.

CONCLUSIONS

Cell-free nDNA and mtDNA are constituents of the amniotic fluid supernatant from PPROM pregnancies. Both cell-free nDNA and mtDNA are involved in the intra-amniotic inflammatory response in women with PPROM.

Gastric fluid used to assess changes during the latency period in preterm prelabor rupture of membranes

OBJECTIVE

To determine changes in the intraamniotic environment during the latency period using paired amniotic and gastric fluid samples in pregnancies complicated by preterm prelabor rupture of membranes (PPROM).

METHODS

A total of 34 women with singleton pregnancies complicated by PPROM prior to 34 weeks were included in the study. Amniotic fluid was obtained by transabdominal amniocentesis at the time of admission. Immediately after delivery, umbilical cord blood and gastric fluid were obtained.

RESULT

Microorganisms in amniotic and gastric fluid samples were found in 38% and 59% of women, respectively. Bedside IL-6 levels were higher in amniotic than in gastric fluid in pregnancies without fetal inflammatory response syndrome (FIRS) (263 pg/mL vs. 50 pg/mL; p < 0.0001), but not in pregnancies with FIRS (318 pg/mL vs. 444 pg/mL; p = 0.91). Funisitis and FIRS was associated with the highest bedside IL-6 levels in gastric fluid. A gastric fluid bedside IL-6 level of 275 pg/mL was found to be the ideal cutoff value to predict funisitis and FIRS.

CONCLUSIONS

The microbial and inflammatory status of the intraamniotic compartment changes during the latency period in PPROM. Bedside IL-6 assessment of gastric fluid may be useful in the rapid diagnosis of funisitis and FIRS.