Mycoplasma hominis and Ureaplasma urealyticum in midtrimester amniotic fluid: association with amniotic fluid cytokine levels and pregnancy outcome

Prevalence of Ureaplasma species among patients at a tertiary hospital in China: a 10-year retrospective study from 2013 to 2022

BACKGROUND

Ureaplasma species are common pathogens of the urogenital tract and can cause a range of diseases. Unfortunately, there is still a scarcity of large-scale and cross-sectional studies on the prevalence of Ureaplasma species in China to clarify their epidemic patterns.

METHODS

This study retrospectively analyzed the data of 18667 patients who visited Peking Union Medical College Hospital for showing various symptoms of (suspected) Ureaplasma species infection during the period 2013-2022. The overall prevalence of Ureaplasma species was calculated, and subgroup analyses were conducted in view of gender, age, specimen types, and diagnosis in every year within the period studied. Furthermore, previous literature that reported on the prevalence of Ureaplasma species in various regions of China was searched and summarized.

RESULTS

The overall positive rate of Ureaplasma species in this study reached 42.1% (7861/18667). Specifically, the prevalence of Ureaplasma species was significantly higher in female patients, while the highest detection rate was found in the 21-50 age group. From 2013 to 2022, there were no significant differences in positive rates of Ureaplasma species among years. However, the detection rate of Ureaplasma species was decreased in COVID-19 period (2020-2022) compared to pre-COVID-19 period (2017-2019). In view of the distribution of patients, outpatients predominated, but the detection rate was lower than inpatients. Urine was the most common specimen type, while cervical swabs had the highest detection rate of Ureaplasma species. When grouped by diagnosis, the highest positive rate of Ureaplasma species was seen in patients with adverse pregnancy outcomes and the lowest rate in patients with prostate disease. The previous literature, although heterogeneous, collectively suggested a high prevalence of Ureaplasma species in China.

CONCLUSIONS

Our study has shown that Ureaplasma species have reached a significant prevalence in China and demands adequate attention.

Modeling an ascending infection by Ureaplasma parvum and its cell signaling and inflammatory response at the feto-maternal interface

PROBLEM

Ascending bacterial infection is associated with ∼ 40% of spontaneous preterm birth (PTB), and Ureaplasma spp. is one of the most common bacteria isolated from the amniotic fluid. Developing novel in vitro models that mimic in vivo uterine physiology is essential to study microbial pathogenesis. We utilized the feto-maternal interface organ-on-chip (FMi-OOC) device and determined the propagation of Ureaplasma parvum, and its impact on cell signaling and inflammation.

METHOD OF STUDY

FMi-OOC is a microphysiologic device mimicking fetal membrane/decidua interconnected through microchannels. The impact of resident decidual CD45+ leukocytes was also determined by incorporating them into the decidual chamber in different combinations with U. parvum. We tested the propagation of live U. parvum from the decidual to the amniochorion membranes (immunocytochemistry and quantitative PCR), determined its impact on cytotoxicity (LDH assay), cell signaling (JESSTM Western Blot), cellular transition (immunostaining for vimentin and cytokeratin), and inflammation (cytokine bead array).

RESULTS

U. parvum transversed the chorion and reached the amnion epithelium after 72 hours but did not induce cell signaling kinases (p38MAPK and JNK) activation, or cellular transition (epithelial-mesenchymal), regardless of the presence of immune cells. The inflammatory response was limited to the choriodecidual interface and did not promote inflammation in the amnion layer.

CONCLUSIONS

Our data suggest that U. parvum is poorly immunogenic and does not produce massive inflammatory changes at the feto-maternal interface. We speculate that the presence of U. parvum may still compromise the feto-maternal interface making it susceptible to other pathogenic infection.

Are bacteria, fungi, and archaea present in the midtrimester amniotic fluid?

OBJECTIVES

This study was conducted to determine whether bacteria, fungi, or archaea are detected in the amniotic fluid of patients who underwent midtrimester amniocentesis for clinical indications.

METHODS

Amniotic fluid samples from 692 pregnancies were tested by using a combination of culture and end-point polymerase chain reaction (PCR) techniques. Intra-amniotic inflammation was defined as an interleukin-6 concentration >2,935 pg/mL.

RESULTS

Microorganisms were detected in 0.3% (2/692) of cases based on cultivation, 1.73% (12/692) based on broad-range end-point PCR, and 2% (14/692) based on the combination of both methods. However, most (13/14) of these cases did not have evidence of intra-amniotic inflammation and delivered at term. Therefore, a positive culture or end-point PCR in most patients appears to have no apparent clinical significance.

CONCLUSIONS

Amniotic fluid in the midtrimester of pregnancy generally does not contain bacteria, fungi, or archaea. Interpretation of amniotic fluid culture and molecular microbiologic results is aided by the assessment of the inflammatory state of the amniotic cavity. The presence of microorganisms, as determined by culture or a microbial signal in the absence of intra-amniotic inflammation, appears to be a benign condition.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Modeling ascending Ureaplasma parvum infection through the female reproductive tract using vagina-cervix-decidua-organ-on-a-chip and feto-maternal interface-organ-on-a-chip

Genital mycoplasmas can break the cervical barrier and cause intraamniotic infection and preterm birth. This study developed a six-chamber vagina-cervix-decidua-organ-on-a-chip (VCD-OOC) that recapitulates the female reproductive tract during pregnancy with culture chambers populated by vaginal epithelial cells, cervical epithelial and stromal cells, and decidual cells. Cells cultured in VCD-OOC were characterized by morphology and immunostaining for cell-specific markers. We transferred the media from the decidual cell chamber of the VCD-OOC to decidual cell chamber in feto-maternal interface organ-on-a-chip (FMi-OOC), which contains the fetal membrane layers. An ascending Ureaplasma parvum infection was created in VCD-OOC. U. parvum was monitored for 48 h post-infection with their cytotoxicity (LDH assay) and inflammatory effects (multiplex cytokine assay) in the cells tested. An ascending U. parvum infection model of PTB was developed using CD-1 mice. The cell morphology and expression of cell-specific markers in the VCD-OOC mimicked those seen in lower genital tract tissues. U. parvum reached the cervical epithelial cells and decidua within 48 h and did not cause cell death in VCD-OOC or FMi-OOC cells. U. parvum infection promoted minimal inflammation, while the combination of U. parvum and LPS promoted massive inflammation in the VCD-OOC and FMi-OOC cells. In the animal model, U. parvum vaginal inoculation of low-dose U. parvum did not result in PTB, and even a high dose had only some effects on PTB (20%). However, intra-amniotic injection of U. parvum resulted in 67% PTB. We report the colonization of U. parvum in various cell types; however, inconsistent, and low-grade inflammation across multiple cell types suggests poor immunogenicity induced by U. parvum.

Adverse pregnancy and birth outcomes associated with Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum: a systematic review and meta-analysis

OBJECTIVES

Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum (genital mycoplasmas) commonly colonise the urogenital tract in pregnant women. This systematic review aims to investigate their role in adverse pregnancy and birth outcomes, alone or in combination with bacterial vaginosis (BV).

METHODS

We searched Embase, Medline and CINAHL databases from January 1971 to February 2021. Eligible studies tested for any of the three genital mycoplasmas during pregnancy and reported on the primary outcome, preterm birth (PTB) and/or secondary outcomes low birth weight (LBW), premature rupture of membranes (PROM), spontaneous abortion (SA) and/or perinatal or neonatal death (PND).Two reviewers independently screened titles and abstracts, read potentially eligible full texts and extracted data. Two reviewers independently assessed risks of bias using published checklists. Random effects meta-analysis was used to estimate summary ORs (with 95% CIs and prediction intervals). Multivariable and stratified analyses were synthesised descriptively.

RESULTS

Of 57/1194 included studies, 39 were from high-income countries. In meta-analysis of unadjusted ORs, M. hominis was associated with PTB (OR 1.87, 95% CI 1.49 to 2.34), PROM, LBW and PND but not SA. U. urealyticum was associated with PTB (OR 1.84, 95% CI 1.34 to 2.55), PROM, LBW, SA and PND. U. parvum was associated with PTB (1.60, 95% CI 1.12 to 2.30), PROM and SA. Nine of 57 studies reported any multivariable analysis. In two studies, analyses stratified by BV status showed that M. hominis and U. parvum were more strongly associated with PTB in the presence than in the absence of BV. The most frequent source of bias was a failure to control for confounding.

CONCLUSIONS

The currently available literature does not allow conclusions about the role of mycoplasmas in adverse pregnancy and birth outcomes, alone or with coexisting BV. Future studies that consider genital mycoplasmas in the context of the vaginal microbiome are needed.

PROSPERO REGISTRATION NUMBER

CRD42016050962.

Genital Mycoplasmas and Biomarkers of Inflammation and Their Association With Spontaneous Preterm Birth and Preterm Prelabor Rupture of Membranes: A Systematic Review and Meta-Analysis

Genital mycoplasmas (GM), such as Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma parvum, and Ureaplasma urealyticum are commonly associated with spontaneous preterm labor (SPTL), spontaneous preterm birth (PTB), and preterm prelabor rupture of membranes (PPROM). This study determined the association between GM and such adverse pregnancy outcomes. We searched for studies published 1980–2019 in MEDLINE, EMBASE, and Web of Science. Studies were eligible when GM was detected during pregnancy. We included 93 and 51 studies in determining the prevalence and the inflammatory biomarkers associated with GM, respectively, using the “metafor” package within R. The protocol was registered with PROSPERO (registration no. CRD42016047297). Women with the studied adverse pregnancy outcomes had significantly higher odds of presence with GM compared to women who delivered at term. For PTB, the odds ratios were: M. hominis (OR: 2.25; CI: 1.35–3.75; I²: 44%), M. genitalium (OR: 2.04; CIL 1.18–3.53; I²: 20%), U. parvum (OR: 1.75; CI: 1.47–2.07; I²: 0%), U. urealyticum (OR: 1.50; CI: 1.08–2.07; I²: 58%). SPTL had significantly higher odds with M. hominis (OR: 1.96; CI: 1.19–3.23; I²: 1%) or U. urealyticum (OR: 2.37; CI: 1.20–4.70; I²: 76%) compared to women without SPTL. Women with PPROM had significantly higher odds with M. hominis (OR: 2.09; CI: 1.42–3.08; I²: 0%) than women without PPROM. However, our subgroup analysis based on the diagnostic test and the sample used for detecting GM showed a higher prevalence of GM in maternal samples than in fetal samples. GM presence of the cervix and vagina was associated with lower odds of PTB and preterm labor (PTL). In contrast, GM presence in the AF, fetal membrane, and placenta was associated with increased odds of PTB and PTL. However, genital mycoplasmas may not elicit the massive inflammation required to trigger PTB. In conclusion, GM presence in the fetal tissues was associated with significantly increased odds of PTB and PTL.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Single Nucleotide Polymorphisms from CSF2, FLT1, TFPI and TLR9 Genes Are Associated with Prelabor Rupture of Membranes

A prelabor rupture of membranes (PROM) and its subtypes, preterm PROM (pPROM) and term PROM (tPROM), are associated with disturbances in the hemostatic system and angiogenesis. This study was designed to demonstrate the role of single nucleotide polymorphisms (SNPs), localized in CSF2 (rs25881), FLT1 (rs722503), TFPI (C-399T) and TLR9 (rs352140) genes, in PROM. A population of 360 women with singleton pregnancy consisted of 180 PROM cases and 180 healthy controls. A single-SNP analysis showed a similar distribution of genotypes in the studied polymorphisms between the PROM or the pPROM women and the healthy controls. Double-SNP TT variants for CSF2 and FLT1 polymorphisms, CC variants for TLR9 and TFPI SNPs, TTC for CSF2, FLT1 and TLR9 polymorphisms, TTT for FLT1, TLR9 and TFPI SNPs and CCCC and TTTC complex variants for all tested SNPs correlated with an increased risk of PROM after adjusting for APTT, PLT parameters and/or pregnancy disorders. The TCT variants for the CSF2, FLT1 and TLR9 SNPs and the CCTC for the CSF2, FLT1, TLR9 and TFPI polymorphisms correlated with a reduced risk of PROM when corrected by PLT and APTT, respectively. We concluded that the polymorphisms of genes, involved in hemostasis and angiogenesis, contributed to PROM.

Ureasplasma and Its Role in Adverse Perinatal Outcomes: A Review

Human Ureaplasma species are the most common microbes found in amniotic fluid and in the placenta after preterm birth, and have previously been correlated with chorioamnionitis, preterm labor, and bronchopulmonary dysplasia, among other adverse birth and neonatal outcomes. Although these correlations exist, there still remains little explanation as to whether Ureaplasma plays a pathogenic role in the development of neonatal disease. In addition, Ureaplasma species are not usually identified on routine culture as they require special culture methods because of their fastidious growth requirements. Treatment of Ureaplasma with macrolides has been shown to effectively eradicate the bacteria in pregnant women and infants. However, it is unclear whether this leads to improved neonatal morbidity and mortality, or whether these generally represent commensal organisms. This review will synthesize the current perspectives about the proposed mechanisms of pathogenicity of Ureaplasma bacteria, its links to poor neonatal outcomes, and the role of screening and treatment in current clinical practice.

Association of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Ureaplasma species infection and organism load with cervicitis in north Indian population

Cervicitis is predominantly caused by Neisseria gonorrhoeae and Chlamydia trachomatis, which accounts for almost half of all the cases of cervicitis. The role of newer organisms like Mycoplasma genitalium and Ureaplasma sp. and association of bacterial load with cervicitis are also not well established. So the study aimed to determine the relative frequency of these organisms and their load in association with cervicitis cases from north India. A case-control study involving 300 women was conducted using quantitative real-time PCR from endocervical swabs for identification of organisms and quantification of bacterial load. Among 150 cervicitis cases, C. trachomatis, N. gonorrhoeae, M. genitalium and Ureaplasma parvum were detected in 5 (3·3%), 10 (6·6%), 37(24·6%) and 47 (31·3%) respectively. Old age (<0·001, chi-squared test) and irregular menstrual cycles (<0·001, chi-squared test) were significantly associated with cervicitis. M genitalium was the only organism to be associated significantly with cervicitis with regard to age (<0·031) and symptoms like discharge (P < 0·033, chi-squared test) and dysuria (P < 0·044, chi-squared test) in multivariate analysis. Our finding suggests that the bacterial load of these organisms is not significantly associated with cervicitis. However, we found significant association of M. genitalium infection with clinical characteristics of cervicitis cases.

Antibody microarray analysis of amniotic fluid proteins associated with subsequent ruptured membranes in women with threatened preterm labor

PROBLEM

We aimed to identify amniotic fluid (AF) proteins associated with the subsequent rupture of membranes (ROM) occurring in the absence of active labor in women with threatened preterm labor (PTL) using an antibody microarray.

METHOD OF THE STUDY

This retrospective cohort study included 183 singleton pregnant women with PTL (24-33 weeks) who underwent amniocentesis. A nested case-control study was conducted using AF samples from 20 women with subsequent ROM within 7 days of sampling (case subjects) and 20 gestational age-matched women with term delivery (TD) without ROM (control subjects), via protein-antibody microarray analysis. Seven candidate proteins of interest were validated via ELISA in the total cohort.

RESULTS

Seventeen proteins displayed significant intergroup differences. ELISA validation confirmed that the levels of EN-RAGE, Fas, IL-8, IP-10, MMP-8, and MMP-9 were significantly higher, whereas IGFBP-3 levels were significantly lower in the AF of women with subsequent ROM within 7 days of sampling than in that of women with TD without ROM. Moreover, the time interval from sampling to membrane rupture was significantly correlated with the expression levels of AF proteins, except for IL-10.

CONCLUSION

Using an antibody microarray, we identified various inflammatory, angiogenic, matrix-degrading, and apoptosis-related proteins in the AF that were associated with subsequent ROM occurring in the absence of active labor in women with threatened PTL. These findings provide novel insights into the molecular mechanisms underlying membrane rupture without active labor in threatened PTL.

Evaluation of the prevalence of sexually transmitted bacterial pathogens in Northern Cyprus by nucleic acid amplification tests, and investigation of the relationship between these pathogens and cervicitis

Objective:

To evaluate the prevalence of pathogens, Chlamydia trachomatis, Neisseria gonorrhea and Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, and Ureaplasma parvum in women via multiplex-polymerase chain reaction (PCR)-deoxyribonucleic acid (DNA).

Materials and Methods:

Cervical swabs of 273 women in reproductive age who underwent gynecologic examination in our outpatient clinic were evaluated using the multiplex-PCR-DNA method. The presence of cervicitis, contraceptive methods, marital status, and the number of partners were evaluated.

Results:

One hundred six (39%) of the 273 women had at least one bacterium, 25 women (9.8%) had two bacteria, and three women (1%) had three bacteria. U. urealyticum was the most frequently encountered bacterium (13.9%), followed by M. hominis (12.8%), U. parvum (12.4%), C. trachomatis (5.4%), M. genitalium (2.9%), N. gonorrhea (2.5%), and T. vaginalis (0.3%). Bacterial infection was detected more frequently in women aged <25 years, single, who had multiple partners, and clinically diagnosed with cervicitis. The cervicitis rate was 39% in our study. M. genitalium was significantly more frequent in women with cervicitis than in women without cervicitis (5.6 vs. 1.2%, p=0.005). C. trachomatis and N. gonorrhea, which are often associated with cervicitis, were comparable in women with and without cervicitis.

Conclusion:

Women with clinically diagnosed cervicitis or even with a normal-appearing cervix should be tested using multiplex-real-time PCR-nucleic-acidamplification tests on suspicion of such an infection. M. genitalium is an emerging bacterial agent for cervicitis along with C. trachomatis and N. gonorrhea.

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.

Infection-mediated preterm birth: Bacterial origins and avenues for intervention

Preterm birth (PTB) is globally the leading cause of death and disability in children under five years of age. Intra-amniotic infection is well recognised as a major cause of PTB. Importantly, it is the most common cause of extreme PTB (birth prior to 28 weeks gestation), which is frequently associated with a wide range of serious neonatal morbidities. Recent developments in next generation sequencing technologies, combined with many years of culture-based microbiological data have allowed us to gain a deeper understanding of the pathogenesis of infection-mediated PTB. In particular, studies have revealed numerous potential routes to intra-amniotic infection beyond the classically described ascending vaginal route. Currently, antibiotic therapy is standard treatment for suspected or confirmed intra-amniotic infection, although its use in this context has had mixed success due to problems ranging from inappropriate antibiotic selection in relation to the target organism/s, to poor transplacental drug passage. In this review, we will draw together evidence from animal models and human studies to characterise pathways to intra-amniotic infection. We will then thoroughly outline current therapeutic protocols for cases of intra-amniotic infection and suggest potential new avenues for treatment.

Evidence that antibiotic administration is effective in the treatment of a subset of patients with intra-amniotic infection/inflammation presenting with cervical insufficiency

BACKGROUND

Cervical insufficiency is a risk factor for spontaneous midtrimester abortion or early preterm birth. Intra-amniotic infection has been reported in 8-52% of such patients and intra-amniotic inflammation in 81%. Some professional organizations have recommended perioperative antibiotic treatment when emergency cervical cerclage is performed. The use of prophylactic antibiotics is predicated largely on the basis that they reduce the rate of complications during the course of vaginal surgery. However, it is possible that antibiotic administration can also eradicate intra-amniotic infection/inflammation and improve pregnancy outcome.

OBJECTIVE

To describe the outcome of antibiotic treatment in patients with cervical insufficiency and intra-amniotic infection/inflammation.

STUDY DESIGN

The study population consisted of 22 women who met the following criteria: (1) singleton pregnancy; (2) painless cervical dilatation of >1 cm between 16.0 and 27.9 weeks of gestation; (3) intact membranes and absence of uterine contractions; (4) transabdominal amniocentesis performed for the evaluation of the microbiologic and inflammatory status of the amniotic cavity; (5) presence of intra-amniotic infection/inflammation; and (6) antibiotic treatment (regimen consisted of ceftriaxone, clarithromycin, and metronidazole). Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction for Ureaplasma spp. was performed. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms or a positive polymerase chain reaction for Ureaplasma spp., and intra-amniotic inflammation was suspected when there was an elevated amniotic fluid white blood cell count (≥19 cells/mm³) or a positive rapid test for metalloproteinase-8 (sensitivity 10 ng/mL). For the purpose of this study, the "gold standard" for diagnosis of intra-amniotic inflammation was an elevated interleukin-6 concentration (>2.6 ng/mL) using an enzyme-linked immunosorbent assay. The results of amniotic fluid interleukin-6 were not available to managing clinicians. Follow-up amniocentesis was routinely offered to monitor the microbiologic and inflammatory status of the amniotic cavity and fetal lung maturity. Treatment success was defined as resolution of intra-amniotic infection/inflammation or delivery ≥34 weeks of gestation.

RESULTS

Of 22 patients with cervical insufficiency and intra-amniotic infection/inflammation, 3 (14%) had microorganisms in the amniotic fluid. Of the 22 patients, 6 (27%) delivered within 1 week of amniocentesis and the remaining 16 (73%) delivered more than 1 week after the diagnostic procedure. Among these, 12 had a repeat amniocentesis to assess the microbial and inflammatory status of the amniotic cavity; in 75% (9/12), there was objective evidence of resolution of intra-amniotic inflammation or intra-amniotic infection demonstrated by analysis of amniotic fluid at the time of the repeat amniocentesis. Of the 4 patients who did not have a follow-up amniocentesis, all delivered ≥34 weeks, 2 of them at term; thus, treatment success occurred in 59% (13/22) of cases.

CONCLUSION

In patients with cervical insufficiency and intra-amniotic infection/inflammation, administration of antibiotics (ceftriaxone, clarithromycin, and metronidazole) was followed by resolution of the intra-amniotic inflammatory process or intra-amniotic infection in 75% of patients and was associated with treatment success in about 60% of cases.

The earlier the gestational age, the greater the intensity of the intra-amniotic inflammatory response in women with preterm premature rupture of membranes and amniotic fluid infection by Ureaplasma species

Objectives To determine the relationship between the intensity of the intra-amniotic inflammatory response and the gestational age at the time of diagnosis in cases with preterm premature rupture of membranes (PROM) and intra-amniotic infection caused by Ureaplasma spp. Methods A retrospective cohort study was conducted which included 71 women with preterm PROM and a positive amniotic fluid culture with Ureaplasma spp. Women with mixed intra-amniotic infections were excluded. The study population was classified into three groups according to gestational age: group 1, <26 weeks (extreme preterm PROM, n = 17); group 2, 26.0-33.9 weeks (moderate preterm PROM, n = 39); group 3, 34.0-36.9 weeks (late preterm PROM, n = 15). The intensity of the intra-amniotic and maternal inflammatory response was compared among the three groups. The intensity of the intra-amniotic inflammatory response was assessed by the concentration of amniotic fluid matrix metalloproteinase-8 (MMP-8) and white blood cell (WBC) count. The maternal inflammatory response was assessed by the concentration of C-reactive protein (CRP) and WBC count in maternal blood at the time of amniocentesis. Results (1) The median values of amniotic fluid MMP-8 concentration and WBC count were the highest in the extreme preterm PROM group and the lowest in the late preterm PROM group (P < 0.001 and P = 0.01, respectively); (2) the intensity of the maternal inflammatory response measured by maternal blood WBC count and CRP concentration was not significantly associated with gestational age at the time of diagnosis. Conclusion The earlier the gestational age at the time of PROM, the higher the intensity of the intra-amniotic inflammatory response in women with preterm PROM and intra-amniotic infection caused by Ureaplasma spp.

The combination of maternal blood and amniotic fluid biomarkers improves the predictive accuracy of histologic chorioamnionitis

INTRODUCTION

This study was performed to determine whether the combination of maternal blood and amniotic fluid biomarkers can improve the predictive accuracy of histologic chorioamnionitis (HC).

METHODS

This retrospective study included 80 singleton pregnant women who were suspected to have intrauterine infection and underwent measurement of two maternal blood biomarkers [maternal white blood cell count (mWBC) and maternal C-reactive protein level (mCRP)] and three amniotic fluid biomarkers [amniotic white blood cell count (aCell), amniotic glucose level (aGlucose), and amniotic lactate dehydrogenase level (aLDH)]. We divided the patients into two groups based on the presence or absence of HC and assessed the predictors of HC using logistic regression models: Model 1, combination of mWBC and mCRP; Model 2, combination of Model 1 and aGlucose; and Model 3, combination of Model 2, aCell, and aLDH.

RESULTS

The multivariable analysis showed that aCell was the only significant predictor of HC [odds ratio, 1.24; 95% confidence interval (CI), 1.06-1.68] independent of mWBC, mCRP, aGlucose, and aLDH. The c-statistics were higher in Model 3 (0.803; 95% CI, 0.701-0.905) than Model 1 (0.634; 95% CI, 0.511-0.758) and Model 2 (0.785; 95% CI, 0.684-0.887).

DISCUSSION

We found that the combination of maternal blood and amniotic fluid biomarkers can improve the predictive accuracy of HC. Therefore, our data provide relevant information to support counseling with regard to improving the predictive accuracy of HC in patients with suspected intrauterine infection.

Predicting BPD: Lessons Learned From the Airway Microbiome of Preterm Infants

Bronchopulmonary dysplasia (BPD) is the chronic lung disease of prematurity with an operational definition, various different clinical phenotypes, and a complex, multifactorial etiology. Newer unbiased systems biology approaches have identified various "omic" factors associated with the pathogenesis and prediction of BPD. Recent microbi "omic" studies have discovered that airways of newborns harbor a low biomass but distinct microbiome signature as early as at the time of birth. This early airway microbiome may serve to prime the host immune system and may play a role in modulating the infant's future susceptibility to severe BPD development. Temporal changes are observed in airway microbiome of preterm infants from birth to the diagnosis of BPD, with an overall decrease in bacterial diversity, and development of a relative dysbiosis marked by increased Gammaproteobacteria and decreased Lactobacilli abundance. This review will summarize previous investigations of the airway microbiome in preterm infants, appraise the utility of using the airway microbiome to predict BPD development, discuss possible molecular mechanisms involved, and speculate on future microbiome-mediated therapeutics for BPD.

Antibiotics for amniotic-fluid colonization by Ureaplasma and/or Mycoplasma spp. to prevent preterm birth: A randomized trial

Objective

To assess whether antibiotics used for treatment in asymptomatic second-trimester women positive for Mycoplasma or Ureaplasma spp. detected by amniotic-fluid PCR prevents preterm delivery.

Design

A randomized, double-blind, placebo-controlled trial.

Setting

10 maternal fetal medicine centers in France.

Population

Women with a singleton pregnancy who underwent amniocentesis between 16 and 20 weeks’ gestation (weeks) for Down syndrome screening. A sample of 238 women with PCR-positive findings per treatment group was needed to show a 50% reduction in the preterm delivery rate.

Methods

Amniotic fluid was tested. Women with positive findings on real-time PCR of amniotic fluid for Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum and Ureaplasma parvum were randomized to receive josamycin or placebo. Amniotic fluid was also tested for 16S PCR.

Main outcome measures

The primary outcome was delivery before 37 weeks.

Results

In total, 1043 women underwent amniotic-fluid screening with specific PCR detection between July 2008 and July 2011: PCR detection failed in 27 (2.6%), and 20 (1.9%) underwent termination of pregnancy. Among the 1016 women with PCR results, 980 had available data for the primary outcome (delivery before 37 weeks) and 29 (3.0%) were positive for Ureaplasma and/or Mycoplasma spp. Because of the low rate of women with PCR-positive findings, the trial was stopped prematurely. In total, 19 women were randomized to receive placebo (n = 8) or josamycin (n = 11) and their characteristics were comparable, as was the rate of preterm delivery and secondary outcomes. In comparing all PCR-positive and -negative women regardless of treatment, PCR positivity for Ureaplasma and/or Mycoplasma spp. was not associated with any adverse pregnancy or neonatal outcome. Amniotic-fluid screening by 16S PCR showed no other bacterial colonization associated with preterm birth.

Conclusions

Because of a low amniotic fluid colonization rate, the trial was interrupted. Maternal amniotic-fluid colonization by Mycoplasma and/or Ureaplasma spp. at 16–20 weeks in asymptomatic women is rare and not associated with adverse pregnancy outcomes.

Trial registration

ClinicalTrials.gov NCT00718705

Investigation on silent bacterial infections in specimens from pregnant women affected by spontaneous miscarriage

Miscarriage is one of the main complications occurring in pregnancy. The association between adverse pregnancy outcomes and silent bacterial infections has been poorly investigated. Ureaplasma parvum and urealiticum, Mycoplasma genitalium and hominis and Chlamydia trachomatis DNA sequences have been investigated by polymerase chain reaction (PCR) methods in chorionic villi tissues and peripheral blood mononuclear cells (PBMCs) from females with spontaneous abortion (SA, n = 100) and females who underwent voluntary interruption of pregnancy (VI, n = 100). U. parvum DNA was detected in 14% and 15% of SA and VI, respectively, with a mean of bacterial DNA load of 1.3 × 10^-1 copy/cell in SA and 2.8 × 10 ^-3 copy/cell in VI; U. urealiticum DNA was detected in 3% and 2% of SA and VI specimens, respectively, with a mean DNA load of 3.3 × 10^-3 copy/cell in SA and 1.6 × 10^-3 copy/cell in VI; M. hominis DNA was detected in 5% of SA specimens with a DNA load of 1.3 × 10^-4 copy/cell and in 6% of VI specimens with a DNA load of 1.4 × 10^-4 copy/cell; C. trachomatis DNA was detected in 3% of SA specimens with a DNA load of 1.5 × 10^-4 copy/cell and in 4% of VI specimens with a mean DNA load of 1.4 × 10^-4 copy/cell. In PBMCs from the SA and VI groups, Ureaplasma spp, Mycoplasma spp and C. trachomatis DNAs were detected with a prevalence of 1%-3%. Bacteria were investigated, for the first time, by quantitative real-time PCR (qPCR) in chorionic villi tissues and PBMCs from women affected by SA and VI. These data may help to understand the role and our knowledge of the silent infections in SA.

Ureaplasma urealyticum: the Role as a Pathogen in Women's Health, a Systematic Review

PURPOSE OF REVIEW

To evaluate the role of Ureaplasma urealyticum as a genital pathogen in women's health. Three aspects were analyzed: (1) preterm delivery (PTD); (2) female infertility; and (3) lower genital tract pathology including pelvic inflammatory disease (PID), cervicitis, and genital discomfort (discharge, burning).

RECENT FINDINGS

A systematic review was performed. Searching PUBMED and EMBASE for published articles from January 2003 to September 2017 using the key word "Ureaplasma urealyticum" yielded 1835 manuscripts. These were further screened using defined inclusion criteria: (1) original peer-reviewed observational studies; (2) English language; (3) U. urealyticum was specifically isolated; (4) present "cases"/"exposed" and "controls"/"unexposed" to enable calculating an association between U. urealyticum and the outcome studied. Altogether, 32 studies were included that underwent quality scoring based on methodology, sample size, study population, and method of identification of U. urealyticum. The association of U. urealyticum and PTD was inconsistent between the studies. Eight of the ten prospective studies failed to show an association between U. urealyticum and PTD, yet four of the six case control studies found a positive association. Regarding female infertility and genital discomfort, five of the six studies for each of these topics failed to find an association. Only two studies met the inclusion criteria for cervicitis with conflicting conclusions. Unfortunately, none of the studies met the inclusion criteria for PID. It seems that U. urealyticum has a limited role as a pathogen in female infertility, cervicitis, PID, and genital discomfort. The role as a pathogen in PTD is unclear and future studies are needed to address this issue.

Ureaplasma isolates stimulate pro-inflammatory CC chemokines and matrix metalloproteinase-9 in neonatal and adult monocytes

Being generally regarded as commensal bacteria, the pro-inflammatory capacity of Ureaplasma species has long been debated. Recently, we confirmed Ureaplasma–driven pro-inflammatory cytokine responses and a disturbance of cytokine equilibrium in primary human monocytes in vitro. The present study addressed the expression of CC chemokines and matrix metalloproteinase-9 (MMP-9) in purified term neonatal and adult monocytes stimulated with serovar 8 of Ureaplasma urealyticum (Uu) and serovar 3 of U. parvum (Up). Using qRT-PCR and multi-analyte immunoassay, we assessed mRNA and protein expression of the monocyte chemotactic proteins 1 and 3 (MCP-1/3), the macrophage inflammatory proteins 1α and 1β (MIP-1α/β) as well as MMP-9. For the most part, both isolates stimulated mRNA expression of all given chemokines and MMP-9 in cord blood and adult monocytes (p<0.05 and p<0.01). These results were paralleled by Uu and Up-induced secretion of MCP-1 protein in both cells (neonatal: p<0.01, adult: p<0.05 and p<0.01). Release of MCP-3, MIP-1α, MIP-1β and MMP-9 was enhanced upon exposure to Up (neonatal: p<0.05, p<0.01 and p<0.001, respectively; adult: p<0.05). Co-stimulation of LPS-primed monocytes with Up increased LPS-induced MCP-1 release in neonatal cells (p<0.05) and aggravated LPS-induced MMP-9 mRNA in both cell subsets (neonatal: p<0.05, adult: p<0.01). Our results document considerable expression of pro-inflammatory CC chemokines and MMP-9 in human monocytes in response to Ureaplasma isolates in vitro, adding to our previous data. Findings from co-stimulated cells indicate that Ureaplasma may modulate monocyte immune responses to a second stimulus.

Histologic chorioamnionitis does not modulate the oxidative stress and antioxidant status in pregnancies complicated by spontaneous preterm delivery

Background

Infection induced-inflammation and other risk factors for spontaneous preterm birth (PTB) and preterm premature rupture of membranes (pPROM) may cause a redox imbalance, increasing the release of free radicals and consuming antioxidant defenses. Oxidative stress, in turn, can initiate intracellular signaling cascades that increase the production of pro-inflammatory mediators.

The objective of this study was to evaluate the oxidative damage to proteins and antioxidant capacity profiles in amniochorion membranes from preterm birth (PTB) and preterm premature rupture of membranes (pPROM) and to determine the role of histologic chorioamnionitis in this scenario.

Methods

We included 27 pregnant women with PTB, 27 pPROM and 30 at term. Protein oxidative damage was assayed by 3-nitrotyrosine (3-NT) and carbonyl levels, using enzyme-linked immunosorbent assay (ELISA) and modified dinitrophenylhydrazine assay (DNPH), respectively. Total antioxidant capacity (TAC) was measured by ELISA.

Results

Protein oxidative damage determined by carbonyl levels was lower in PTB group than pPROM and term groups (p < 0.001). PTB group presented higher TAC compared with pPROM and term groups (p = 0.002). Histologic chorioamnionitis did not change either protein oxidative damage or TAC regardless of gestational outcome.

Conclusion

These results corroborates previous reports that pPROM and term birth exhibit similarities in oxidative stress- induced senescence and histologic chorioamnionitis does not modulate oxidative stress or antioxidant status.

The vaginal microbiome of pregnant women is less rich and diverse, with lower prevalence of Mollicutes, compared to non-pregnant women

The vaginal microbiome plays an important role in maternal and neonatal health. Imbalances in this microbiota (dysbiosis) during pregnancy are associated with negative reproductive outcomes, such as pregnancy loss and preterm birth, but the underlying mechanisms remain poorly understood. Consequently a comprehensive understanding of the baseline microbiome in healthy pregnancy is needed. We characterized the vaginal microbiomes of healthy pregnant women at 11–16 weeks of gestational age (n = 182) and compared them to those of non-pregnant women (n = 310). Profiles were created by pyrosequencing of the cpn60 universal target region. Microbiome profiles of pregnant women clustered into six Community State Types: I, II, III, IVC, IVD and V. Overall microbiome profiles could not be distinguished based on pregnancy status. However, the vaginal microbiomes of women with healthy ongoing pregnancies had lower richness and diversity, lower prevalence of Mycoplasma and Ureaplasma and higher bacterial load when compared to non-pregnant women. Lactobacillus abundance was also greater in the microbiomes of pregnant women with Lactobacillus-dominated CSTs in comparison with non-pregnant women. This study provides further information regarding characteristics of the vaginal microbiome of low-risk pregnant women, providing a baseline for forthcoming studies investigating the diagnostic potential of the microbiome for prediction of adverse pregnancy outcomes.

Microbial invasion of the amniotic cavity in midtrimester pregnancies using molecular microbiology

OBJECTIVE

The objective of the study was to determine the frequency of microbial invasion of the amniotic cavity in the midtrimester of pregnancy in patients undergoing amniocentesis for clinical indications.

STUDY DESIGN

This was a prospective investigation of the amniotic fluid of 344 asymptomatic women recruited in midpregnancy for the presence of microbial DNA. Amniotic samples obtained at the time of amniocentesis for genetic testing on women between 15 and 22 weeks of gestation were tested specifically for the presence of Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma hominis, and Mycoplasma genitalium as well as for other bacteria and fungi using broad-range polymerase chain reaction only. Pregnancy outcomes were reviewed independent of all molecular test results.

RESULTS

Using broad-range polymerase chain reaction, the prevalence of microbial invasion of the amniotic cavity in women between 15 and 22 weeks of gestation was 0% (0 vs 344). Early preterm delivery occurred in only 4 women (1%); 1 delivered electively and 3 spontaneously. None were associated with Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma hominis, or Mycoplasma genitalium. In addition, broad range polymerase chain reaction did not reveal the presence of other bacterial or fungal microbes.

CONCLUSION

Microbial invasion of the amniotic cavity in midtrimester gestations of low-risk pregnant women was not detected using molecular methods in 344 patients.

Ureaplasma urealyticum and U. parvum in sexually active women attending public health clinics in Brazil

Ureaplasma urealyticum and U. parvum have been associated with genital infections. The purpose of this study was to detect the presence of ureaplasmas and other sexually transmitted infections in sexually active women from Brazil and relate these data to demographic and sexual health, and cytokines IL-6 and IL-1β. Samples of cervical swab of 302 women were examined at the Family Health Units in Vitória da Conquista. The frequency of detection by conventional PCR was 76·2% for Mollicutes. In qPCR, the frequency found was 16·6% for U. urealyticum and 60·6% U. parvum and the bacterial load of these microorganisms was not significantly associated with signs and symptoms of genital infection. The frequency found for Trichomonas vaginalis, Neisseria gonorrhoeae, Gardnerella vaginalis and Chlamydia trachomatis was 3·0%, 21·5%, 42·4% and 1·7%, respectively. Higher levels of IL-1β were associated with control women colonized by U. urealyticum and U. parvum. Increased levels of IL-6 were associated with women who exhibited U. parvum. Sexually active women, with more than one sexual partner in the last 3 months, living in a rural area were associated with increased odds of certain U. parvum serovar infection.

Prediction of chorioamnionitis in cases of intraamniotic infection by ureaplasma urealyticum in women with very preterm premature rupture of membranes or preterm labour

OBJECTIVES

First, to determinate the frequency of chorioamnionitis and funisitis in cases of intramniotic detection of Ureaplasma urealyticum. Second, to assess the predictive capability of some biological markers in the amniotic fluid of these women to predict histological inflammation.

SUBJECTS AND METHODS

We prospectively studied 20 cases of women with premature rupture of membranes or preterm labour (PROM) or preterm labour and intraamniotic detection of Ureaplasma urealyticum. Gestational age at admission was 26.74 ± 2.53 weeks. Amniotic fluid concentrations of IL18, IL 2, IL4, IL6, IL10, IL12, TNF-alpha, IFN-g, and MMP-8 were measured by the Multiplex method. Amniotic fluid glucose and leukocyte count were also measured by standard methods. Placental detailed histological studies were performed. Student's t-test, forward stepwise conditional binary logistic regression analysis and ROC curves were used.

RESULTS

Histological chorioamnionitis was present in 45% of cases (9/20) and funisitis just in 15% (3/20). Interleukins 6, 8, 12, MMP-8, and leukocyte count were significantly elevated in cases of histological inflammation, defined as choriamnionitis or chorioamniotis + funisitis (p = .007, .03, .01, .03, .03, respectively) while glucose was decreased (p = .04). Binary logistic regression for the prediction of inflammation showed a high predictive value (R² = .66, p = .002) including in the equation only the IL6 value.

CONCLUSIONS

A significant percentage of cases with intraamniotic detection of Ureaplasma urealyticum shows no pathological signs of histological inflammation. Concentration of Interleukin 6 in amniotic fluid can be useful for the diagnosis of subclinical chorioamnionitis in these cases.

Twenty-four percent of patients with clinical chorioamnionitis in preterm gestations have no evidence of either culture-proven intraamniotic infection or intraamniotic inflammation

BACKGROUND

Recent studies on clinical chorioamnionitis at term suggest that some patients with this diagnosis have neither intraamniotic infection nor intraamniotic inflammation. A false-positive diagnosis of clinical chorioamnionitis in preterm gestation may lead to unwarranted preterm delivery.

OBJECTIVE

We sought to determine the frequency of intraamniotic inflammation and microbiologically proven amniotic fluid infection in patients with preterm clinical chorioamnionitis.

STUDY DESIGN

Amniocentesis was performed in singleton pregnant women with preterm clinical chorioamnionitis (<36 weeks of gestation). Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas and assayed for matrix metalloproteinase-8 concentration. Microbial invasion of the amniotic cavity was defined as a positive amniotic fluid culture; intraamniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration of >23 ng/mL. Nonparametric and survival techniques were used for analysis.

RESULTS

Among patients with preterm clinical chorioamnionitis, 24% (12/50) had neither microbiologic evidence of intraamniotic infection nor intraamniotic inflammation. Microbial invasion of the amniotic cavity was present in 34% (18/53) and intraamniotic inflammation in 76% (38/50) of patients. The most common microorganisms isolated from the amniotic cavity were the Ureaplasma species. Finally, patients without microbial invasion of the amniotic cavity or intraamniotic inflammation had significantly lower rates of adverse outcomes (including lower gestational age at delivery, a shorter amniocentesis-to-delivery interval, acute histologic chorioamnionitis, acute funisitis, and significant neonatal morbidity) than those with microbial invasion of the amniotic cavity and/or intraamniotic inflammation.

CONCLUSION

Among patients with preterm clinical chorioamnionitis, 24% had no evidence of either intraamniotic infection or intraamniotic inflammation, and 66% had negative amniotic fluid cultures, using standard microbiologic techniques. These observations call for a reexamination of the criteria used to diagnose preterm clinical chorioamnionitis.

The Human Ureaplasma Species as Causative Agents of Chorioamnionitis

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

A Case-control Study on the Relationship between Mycoplasma genitalium Infection in Women with Normal Pregnancy and Spontaneous Abortion using Polymerase Chain Reaction

OBJECTIVES

Mycoplasma genitalium infections are suggested as causes of a number of pathological outcomes in pregnant women. The aim of this study was to evaluate the frequency of M. genitalium infections among pregnant women and its association with spontaneous abortion.

METHODS

In this case-control study we included 109 women with spontaneous abortion with a gestational age of 10-20 weeks (patients), and 109 women with normal pregnancy with a gestational age of 20-37 weeks (controls) in Sanandaj, Iran. Using specific primers and extracted DNA from endocervical swabs, a polymerase chain reaction was conducted for the detection of M. genitalium infection in both groups.

RESULTS

The frequency of M. genitalium infection in patient and control groups was one (0.91%) and three (2.75%), respectively. In both control and patient groups using Fisher test, no association between mycoplasma infection and spontaneous abortion was seen.

CONCLUSION

M. genitalium may be positive in the genital tract of some pregnant women but was not associated with spontaneous abortion. Further powerful studies with larger sample sizes are needed for the determination of a possible role of M. genitalium in pregnancy outcomes and spontaneous abortion.

Gastric fluid versus amniotic fluid analysis for the identification of intra-amniotic infection due to Ureaplasma species

OBJECTIVE

Early neonatal sepsis is often due to intra-amniotic infection. The stomach of the neonate contains fluid swallowed before and during delivery. The presence of bacteria as well as neutrophils detected by culture or Gram stain of the gastric fluid during the first day of life is suggestive of exposure to bacteria or inflammation. We undertook this study to determine the relationship between gastric fluid analysis and amniotic fluid obtained by transabdominal amniocentesis in the detection of Ureaplasma species, the most frequent microorganisms responsible for intra-amniotic infection.

MATERIALS AND METHODS

The study population consisted of 100 singleton pregnant women who delivered preterm neonates (<35 weeks) within 7 days of amniocentesis. Gastric fluid of newborns was obtained by nasogastric intubation on the day of birth. Amniotic fluid and gastric fluid were cultured for genital Mycoplasmas, and polymerase chain reaction (PCR) for Ureaplasma species was performed. Intra-amniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL).

RESULTS

(1) Ureaplasma species were detected by culture or PCR in 18% (18/100) of amniotic fluid samples and in 5% (5/100) of gastric fluid samples; (2) among the amniotic fluid cases positive for Ureaplasma species, these microorganisms were identified in 27.8% (5/18) of gastric fluid samples; (3) none of the cases negative for Ureaplasma species in the amniotic fluid were found to be positive for these microorganisms in the gastric fluid; (4) patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms had a significantly higher rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death than those with both amniotic fluid and gastric fluid negative for Ureaplasma species; and (5) no significant differences were observed in the rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death between patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms and those with both amniotic fluid and gastric fluid positive for Ureaplasma species.

CONCLUSIONS

Gastric fluid analysis has 100% specificity in the identification of intra-amniotic infection with Ureaplasma species. However, the detection of Ureaplasma species by culture or PCR in the gastric fluid of neonates at birth did not identify these microorganisms in two-thirds of cases with microbial invasion of the amniotic cavity. Thus, amniotic fluid analysis is superior to that of gastric fluid in the identification of intra-amniotic infection.

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Advances in the Prevention of Infection-Related Preterm Birth

Infection-related preterm birth (PTB) is more common at early gestational ages and is associated with major neonatal mortality and morbidity. Abnormal genital tract microflora in early pregnancy predicts late miscarriage and early PTB. Accordingly, it is logical to consider antibiotics as an intervention. Unfortunately, the conclusions of systematic reviews and meta-analyses (SR&MAs) carried out in an attempt to explain the confusion over the heterogeneity of individual studies are flawed by the fact that undue reliance was placed on studies which: (a) had a suboptimal choice of antibiotic (mainly metronidazole) or used antibiotics not recommended for the treatment of bacterial vaginosis (BV) or BV-related organisms; (b) used antibiotics too late in pregnancy to influence outcome (23–27 weeks); and (c) included women whose risk of PTB was not due to abnormal genital tract colonization and hence unlikely to respond to antibiotics. These risks included: (a) previous PTB of indeterminate etiology; (b) low weight/body mass index; or (c) detection of fetal fibronectin, ureaplasmas, Group B streptococcus or Trichomonas vaginalis). While individual studies have found benefit of antibiotic intervention for the prevention of PTB, in meta-analyses these effects have been negated by large methodologically flawed studies with negative results. As a result, many clinicians think that any antibiotic given at any time in pregnancy to any woman at risk of PTB will cause more harm than good. Recently, a more focused SR&MA has demonstrated that antibiotics active against BV-related organisms, used in women whose risk of PTB is due to abnormal microflora, and used early in pregnancy before irreversible inflammatory damage has occurred, can reduce the rate of PTB. This review presents those data, the background and attempts to explain the confusion using new information from culture-independent molecular-based techniques. It also gives guidance on the structure of putative future antibiotic intervention studies.

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

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

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Mid-trimester amniotic fluid pro-inflammatory biomarkers predict the risk of spontaneous preterm delivery in twins: a retrospective cohort study

OBJECTIVE

To evaluate the association between the concentrations of immune-related proteins in mid-trimester amniotic fluid (AF) and the subsequent risk of spontaneous preterm delivery in twins.

STUDY DESIGN

The study population consisted of consecutive women with a twin pregnancy who underwent clinically indicated genetic amniocentesis at 15 to 20 weeks, and had a subsequent spontaneous delivery in the early preterm period (<32 weeks (cases)) or at term (37 to 42 weeks (controls)). AF was analyzed for cytokines (interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13 and IL-15, interferon-γ, tumor necrosis factor-α), matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9 and MMP-12), and chemokines (complement factor-D/Adipsin, Serpin E1/PAI-1, Adiponectin/Acrp30, C-Reactive Protein, CCL2/MCP-1, Leptin, Resistin) using multiplex immunoassay kits. The association between AF protein levels and subsequent early preterm birth were examined.

RESULT

A total of 96 sets of twins were enrolled, including 17 early preterm birth cases and 79 term controls. AF concentrations of IL-6, IL-8, MMP-3, MMP-8 and MMP-9, and CCL2/MCP-1 were significantly higher in cases than controls. Among these analytes, the combination of AF IL-8 and MMP-9 values had the highest predictive value for early preterm birth. The risk was 8% (10/132) for IL-8<1200 pg ml(-1) and MMP-9<1000 pg ml(-1), 30% (15/50) for IL-8>1200 pg ml(-1) or MMP-9>1000 pg ml(-1), and 90% (9/10) for IL-8>1200 pg ml(-1) and MMP-9>1000 pg ml(-1) (P<0.001).

CONCLUSION

High concentrations of IL-8 and MMP-9 in mid-trimester AF in twins predicted well the risk of early preterm birth.

Sterile intra-amniotic inflammation in asymptomatic patients with a sonographic short cervix: prevalence and clinical significance

OBJECTIVE

To determine the frequency and clinical significance of sterile and microbial-associated intra-amniotic inflammation in asymptomatic patients with a sonographic short cervix.

METHODS

Amniotic fluid (AF) samples obtained by transabdominal amniocentesis from 231 asymptomatic women with a sonographic short cervix [cervical length (CL) ≤25 mm] were analyzed using cultivation techniques (for aerobic and anaerobic as well as genital mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). The frequency and magnitude of intra-amniotic inflammation [defined as an AF interleukin (IL)-6 concentration ≥2.6 ng/mL], acute histologic placental inflammation, spontaneous preterm delivery (sPTD), and the amniocentesis-to-delivery interval were examined according to the results of AF cultures, PCR/ESI-MS and AF IL-6 concentrations.

RESULTS

Ten percent (24/231) of patients with a sonographic short cervix had sterile intra-amniotic inflammation (an elevated AF IL-6 concentration without evidence of microorganisms using cultivation and molecular methods). Sterile intra-amniotic inflammation was significantly more frequent than microbial-associated intra-amniotic inflammation [10.4% (24/231) versus 2.2% (5/231); p < 0.001]. Patients with sterile intra-amniotic inflammation had a significantly higher rate of sPTD <34 weeks of gestation [70.8% (17/24) versus 31.6% (55/174); p < 0.001] and a significantly shorter amniocentesis-to-delivery interval than patients without intra-amniotic inflammation [median 35, (IQR: 10-70) versus median 71, (IQR: 47-98) days, (p < 0.0001)].

CONCLUSION

Sterile intra-amniotic inflammation is more common than microbial-associated intra-amniotic inflammation in asymptomatic women with a sonographic short cervix, and is associated with increased risk of sPTD (<34 weeks). Further investigation is required to determine the causes of sterile intra-amniotic inflammation and the mechanisms whereby this condition is associated with a short cervix and sPTD.

Identification of a gene in Mycoplasma hominis associated with preterm birth and microbial burden in intraamniotic infection

OBJECTIVE

Microbial invasion of the amniotic cavity is associated with spontaneous preterm labor and adverse pregnancy outcome, and Mycoplasma hominis often is present. However, the pathogenic process by which M hominis invades the amniotic cavity and gestational tissues, often resulting in chorioamnionitis and preterm birth, remains unknown. We hypothesized that strains of M hominis vary genetically with regards to their potential to invade and colonize the amniotic cavity and placenta.

STUDY DESIGN

We sequenced the entire genomes of 2 amniotic fluid isolates and a placental isolate of M hominis from pregnancies that resulted in preterm births and compared them with the previously sequenced genome of the type strain PG21. We identified genes that were specific to the amniotic fluid/placental isolates. We then determined the microbial burden and the presence of these genes in another set of subjects from whom samples of amniotic fluid had been collected and were positive for M hominis.

RESULTS

We identified 2 genes that encode surface-located membrane proteins (Lmp1 and Lmp-like) in the sequenced amniotic fluid/placental isolates that were truncated severely in PG21. We also identified, for the first time, a microbial gene of unknown function that is referred to in this study as gene of interest C that was associated significantly with bacterial burden in amniotic fluid and the risk of preterm delivery in patients with preterm labor.

CONCLUSION

A gene in M hominis was identified that is associated significantly with colonization and/or infection of the upper reproductive tract during pregnancy and with preterm birth.

Whole blood flow cytometric analysis of Ureaplasma-stimulated monocytes from pregnant women

We hypothesised that circulating monocytes of women with vaginal colonisation with Ureaplasma spp., genital microorganisms known to cause inflammation-driven preterm birth, would elicit a tolerised cytokine response to subsequent in vitro Ureaplasma parvum serovar 3 (UpSV3) stimulation. Using multi-parameter flow cytometry, we found no differences with regard to maternal colonisation status in the frequency of TNF-α-, IL-6-, IL-8- and IL-1β-expressing monocytes in response to subsequent UpSV3 stimulation (P > 0.10 for all cytokines). We conclude that vaginal Ureaplasma spp. colonisation does not specifically tolerise monocytes of pregnant women towards decreased responses to subsequent stimulation.

Clinical chorioamnionitis at term I: microbiology of the amniotic cavity using cultivation and molecular techniques

INTRODUCTION

The objectives of this study were: 1) to determine the amniotic fluid (AF) microbiology of patients with the diagnosis of clinical chorioamnionitis at term using both cultivation and molecular techniques; and 2) to examine the relationship between intra-amniotic inflammation with and without microorganisms and placental lesions consistent with acute AF infection.

METHODS

The AF samples obtained by transabdominal amniocentesis from 46 women with clinical signs of chorioamnionitis at term were analyzed using cultivation techniques (for aerobic and anerobic bacteria as well as genital mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). The frequency of microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation [defined as an AF interleukin 6 (IL-6) concentration ≥2.6 ng/mL], and placental lesions consistent with acute AF infection (acute histologic chorioamnionitis and/or acute funisitis) were examined according to the results of AF cultivation and PCR/ESI-MS as well as AF IL-6 concentrations.

RESULTS

1) Culture identified bacteria in AF from 46% (21/46) of the participants, whereas PCR/ESI-MS was positive for microorganisms in 59% (27/46) – combining these two tests, microorganisms were detected in 61% (28/46) of patients with clinical chorioamnionitis at term. Eight patients had discordant test results; one had a positive culture and negative PCR/ESI-MS result, whereas seven patients had positive PCR/ESI-MS results and negative cultures. 2) Ureaplasma urealyticum (n=8) and Gardnerella vaginalis (n=10) were the microorganisms most frequently identified by cultivation and PCR/ESI-MS, respectively. 3) When combining the results of AF culture, PCR/ESI-MS and AF IL-6 concentrations, 15% (7/46) of patients did not have intra-amniotic inflammation or infection, 6.5% (3/46) had only MIAC, 54% (25/46) had microbial-associated intra-amniotic inflammation, and 24% (11/46) had intra-amniotic inflammation without detectable microorganisms. 4) Placental lesions consistent with acute AF infection were significantly more frequent in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [70.8% (17/24) vs. 28.6% (2/7); P=0.04].

CONCLUSION

Microorganisms in the AF were identified in 61% of patients with clinical chorioamnionitis at term; 54% had microbial-associated intra-amniotic inflammation, whereas 24% had intra-amniotic inflammation without detectable microorganisms.

The Maternal Serological Response to Intrauterine Ureaplasma sp. Infection and Prediction of Risk of Pre-Term Birth

Pre-term birth (PTB) associated with intrauterine infection and inflammation (IUI) is the major cause of early PTB less than 32 weeks of gestation. Ureaplasma spp. are common commensals of the urogenital tract in pregnancy and are the most commonly identified microorganisms in amniotic fluid of pre-term pregnancies. While we have an understanding of the causal relationship between intra-amniotic infection, inflammation and PTB, we are still unable to explain why vaginal Ureaplasma sp. colonization is tolerated in some women but causes PTB in others. It is now known that placental tissues are frequently colonized by bacteria even in apparently healthy pregnancies delivered at term; usually this occurs in the absence of a significant local inflammatory response. It appears, therefore, that the site, nature, and magnitude of the immune response to infiltrating microorganisms are key in determining pregnancy outcome. Some evidence exists that the maternal serological response to Ureaplasma sp. colonization may be predictive of adverse pregnancy outcome, although issues such as the importance of virulence factors (serovars) and the timing, magnitude, and functional consequences of the immune response await clarification. This mini-review discusses the evidence linking the maternal immune response to risk of PTB and the potential applications of maternal serological analysis for predicting obstetric outcome.

A potential pathogenic factor from Mycoplasma hominis is a TLR2-dependent, macrophage-activating, P50-related adhesin

PROBLEM

Mycoplasma hominis has been implicated in many inflammatory conditions of the human urogenital tract in particular amniotic infections that lead to fetal and neonatal disease and pre-term labor. The mechanisms responsible are poorly defined.

METHOD OF STUDY

Biochemical and immunological methods were used to extract, purify, and characterize an inflammatory component present in M. hominis.

RESULTS

We isolated and purified to homogeneity a 40-kDa bioactive lipoprotein from M. hominis that was a potent TLR2-dependent, CD14-independent activator of the human THP-1 macrophage cell line. Homology searches of the N-terminal sequence revealed that 22 of the first 23 residues were identical to those seen for the phase-variable M. hominis p50 adhesin. The truncated P50t lipoprotein importantly retained its adhesive properties for human macrophages.

CONCLUSION

The unique adhesin/macrophage activator may play a key role in M. hominis infections by triggering an inflammatory cytokine cascade.