A specific bacterial DNA signature in the vagina of Australian women in midpregnancy predicts high risk of spontaneous preterm birth (the Predict1000 study).

BACKGROUND: Intrauterine infection accounts for a quarter of the cases of spontaneous preterm birth; however, at present, it is not possible to efficiently identify pregnant women at risk to deliver preventative treatments. OBJECTIVE: This study aimed to establish a vaginal microbial DNA test for Australian women in midpregnancy that will identify those at increased risk of spontaneous preterm birth. STUDY DESIGN: A total of 1000 women with singleton pregnancies were recruited in Perth, Australia. Midvaginal swabs were collected between 12 and 23 weeks' gestation. DNA was extracted for the detection of 23 risk-related microbial DNA targets by quantitative polymerase chain reaction. Obstetrical history, pregnancy outcome, and demographics were recorded. RESULTS: After excluding 64 women owing to losses to follow-up and insufficient sample for microbial analyses, the final cohort consisted of 936 women of predominantly white race (74.3%). The overall preterm birth rate was 12.6% (118 births); the spontaneous preterm birth rate at <37 weeks' gestation was 6.2% (2.9% at ≤34 weeks' gestation), whereas the preterm premature rupture of the membranes rate was 4.2%. No single individual microbial target predicted increased spontaneous preterm birth risk. Conversely, women who subsequently delivered at term had higher amounts of Lactobacillus crispatus, Lactobacillus gasseri, or Lactobacillus jensenii DNA in their vaginal swabs (13.8% spontaneous preterm birth vs 31.2% term; P=.005). In the remaining women, a specific microbial DNA signature was identified that was strongly predictive of spontaneous preterm birth risk, consisting of DNA from Gardnerella vaginalis (clade 4), Lactobacillus iners, and Ureaplasma parvum (serovars 3 and 6). Risk prediction was improved if Fusobacterium nucleatum detection was included in the test algorithm. The final algorithm, which we called the Gardnerella Lactobacillus Ureaplasma (GLU) test, was able to detect women at risk of spontaneous preterm birth at <37 and ≤34 weeks' gestation, with sensitivities of 37.9% and 44.4%, respectively, and likelihood ratios (plus or minus) of 2.22 per 0.75 and 2.52 per 0.67, respectively. Preterm premature rupture of the membranes was more than twice as common in GLU-positive women. Adjusting for maternal demographics, ethnicity, and clinical history did not improve prediction. Only a history of spontaneous preterm birth was more effective at predicting spontaneous preterm birth than a GLU-positive result (odds ratio, 3.6). CONCLUSION: We have identified a vaginal bacterial DNA signature that identifies women with a singleton pregnancy who are at increased risk of spontaneous preterm birth and may benefit from targeted antimicrobial therapy.

Vaginal bacterial load in the second trimester is associated with early preterm birth recurrence: a nested case-control study.

OBJECTIVE: To assess the association between vaginal microbiome (VMB) composition and recurrent early spontaneous preterm birth (sPTB)/preterm prelabour rupture of membranes (PPROM). DESIGN: Nested case-control study. SETTING: UK tertiary referral hospital. SAMPLE: High-risk women with previous sPTB/PPROM <34+0 weeks' gestation who had a recurrence (n = 22) or delivered at ≥37+0 weeks without PPROM (n = 87). METHODS: Vaginal swabs collected between 15 and 22 weeks' gestation were analysed by 16S rRNA gene sequencing and 16S quantitative PCR. MAIN OUTCOME MEASURE: Recurrent early sPTB/PPROM. RESULTS: Of the 109 high-risk women, 28 had anaerobic vaginal dysbiosis, with the remainder dominated by lactobacilli (Lactobacillus iners 36/109, Lactobacillus crispatus 23/109, or other 22/109). VMB type and diversity were not associated with recurrence. Women with a recurrence, compared to those without, had a higher median vaginal bacterial load (8.64 versus 7.89 log10 cells/mcl, adjusted odds ratio [aOR] 1.90, 95% CI 1.01-3.56, P = 0.047) and estimated Lactobacillus concentration (8.59 versus 7.48 log10 cells/mcl, aOR 2.35, (95% CI 1.20-4.61, P = 0.013). A higher recurrence risk was associated with higher median bacterial loads for each VMB type after stratification, although statistical significance was reached only for L. iners domination (aOR 3.44, 95% CI 1.06-11.15, P = 0.040). Women with anaerobic dysbiosis or L. iners domination had a higher median vaginal bacterial load than women with a VMB dominated by L. crispatus or other lactobacilli (8.54, 7.96, 7.63, and 7.53 log10 cells/mcl, respectively). CONCLUSIONS: Vaginal bacterial load is associated with early sPTB/PPROM recurrence. Domination by lactobacilli other than L. iners may protect women from developing high bacterial loads. Future PTB studies should quantify vaginal bacteria and yeasts. TWEETABLE ABSTRACT: Increased vaginal bacterial load in the second trimester may be associated with recurrent early spontaneous preterm birth.

Streptococcus agalactiae do not penetrate human chorioamniotic membranes in vitro but alter their biomechanical properties.

INTRODUCTION: Vaginal colonization with Streptococcus agalactiae (group B streptococci) is hypothesized to constitute a risk factor for preterm prelabor rupture of membranes. In vitro studies have shown that S. agalactiae strains isolated from infants with neonatal sepsis adhere to chorion cells of the human chorioamniotic membrane. However, it is still unknown whether S. agalactiae strains penetrate the chorioamniotic membranes and whether S. agalactiae colonization affects the biomechanical properties of the membranes and thus contributes to increased risk of preterm prelabor rupture. The aim of this in vitro study was to explore if different strains of S. agalactiae penetrate and affect the biomechanical properties of human chorioamniotic membranes. MATERIAL AND METHODS: Three different strains of S. agalactiae were obtained, one from an early-onset neonatal infection, one from a case of preterm prelabor rupture of membranes and one from a healthy pregnant carrier. Chorioamniotic membranes from elective cesarean deliveries were either incubated with S. agalactiae or mounted in a two-chamber incubation cell generating a "maternal" and a "fetal" chamber and incubated with S. agalactiae in the maternal chamber. Subsequently the membranes were examined to evaluate S. agalactiae attachment, penetration and the effect on the biomechanical properties. RESULTS: At 5 h after incubation, S. agalactiae adhered to the chorioamniotic membranes with increased number at 20 h. Streptococcus agalactiae did not penetrate the membranes even after 20 h of incubation. Streptococcus agalactiae increased the ultimate tensile stress needed to rupture the membranes and increased the work needed to rupture the membranes as well as the elastic modulus. CONCLUSIONS: Human chorioamniotic membranes constitute a physical barrier against S. agalactiae infections. Moreover, S. agalactiae infection leads to increased strength of the membranes.

Erythromycin compared to amoxicillin and azithromycin for antimicrobial prophylaxis for preterm premature rupture of the membranes: a retrospective study.

Antimicrobial prophylaxis is widely recommended for pregnant women who have preterm premature rupture of the membranes. Erythromycin prophylaxis was used during an initial period (control) and then changed to intravenous amoxicillin for 48 h, followed by 5 days of oral amoxicillin along with a single dose of azithromycin (case). Healthcare records were reviewed retrospectively. The primary outcome was latency (between membrane rupture and delivery) and the secondary outcomes were mode of delivery, maternal high dependency unit (HDU) admission, and several laboratory parameters. There were 78 women in the case group (amoxicillin and azithromycin) and controls were selected on a 1:1 ratio. There was no statistically significant difference between cases and controls with respect to group B Streptococcus or E.coli carriage, previous preterm birth, assissted fertility and parity. No babies had a positive blood culture with Group B Streptococcus. There was a longer latency to delivery for those prescribed amoxicillin and azithromycin (median = 5.5 days), compared with controls on erythromycin (median = 2 days, p < .001). There was no difference in the mode of delivery or maternal HDU admission. Given the potential sequelae of preterm birth, this warrants further prospective investigation in a randomised control trial.IMPACT STATEMENTWhat is already known on this subject? Antimicrobial prophylaxis is recommended for women who have preterm premature rupture of the membranes (PPROM). It has been shown to increase latency of delivery. However there are different regimens recommended in North America (amoxicillin and a macrolide) and the United Kingdom (macrolide monotherapy).What do the results of this study add? This study has shown that in our population, women who were prescribed the PPROM regimen of amoxicillin with azithromycin had a longer median latency from time of rupture of membranes to delivery, than women in a historical control group who were prescribed erythromycin monotherapy.What are the implications of these findings for clinical practice and/or further research? This retrospective study has shown that there may be a difference in latency between different antimicrobial prophylaxis regimens for PPROM. A randomised control trial, with sufficient patient numbers, is needed to determine the best regimen for prophylaxis, and would allow harmonisation of international guidelines.

MicroRNA Signature of Epithelial-Mesenchymal Transition in Group B Streptococcal Infection of the Placental Chorioamniotic Membranes.

BACKGROUND: Infection-induced preterm birth is a major cause of neonatal mortality and morbidity and leads to preterm premature rupture of placental chorioamniotic membranes. The loss of amniotic epithelial cells and tensile strength preceding membrane rupture is poorly understood. We hypothesized that intrauterine bacterial infection induces changes in microRNA (miRNA) expression, leading to amniotic epithelial cell loss and membrane weakening. METHODS: Ten pregnant pigtail macaques received choriodecidual inoculation of either group B Streptococcus (GBS) or saline (n = 5/group). Placental chorioamniotic membranes were studied using RNA microarray and immunohistochemistry. Chorioamniotic membranes from women with preterm premature rupture of membranes (pPROM) and normal term pregnancies were studied using transmission electron microscopy. RESULTS: In our model, an experimental GBS infection was associated with changes in the miRNA profile in the chorioamniotic membranes consistent with epithelial to mesenchymal transition (EMT) with loss of epithelial (E-cadherin) and gain of mesenchymal (vimentin) markers. Similarly, loss of desmosomes (intercellular junctions) was seen in placental tissues from women with pPROM. CONCLUSIONS: We describe EMT as a novel mechanism for infection-associated chorioamniotic membrane weakening, which may be a common pathway for many etiologies of pPROM. Therapy based on anti-miRNA targeting of EMT may prevent pPROM due to perinatal infection.

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.

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.

Characteristics and influence of Mycoplasma/Ureaplasma cultures in amniotic fluid on perinatal outcomes.

AIM: To investigate the effects of Mycoplasma/Ureaplasma cultured in amniotic fluid on perinatal characteristics in preterm delivery between 22 and 33 weeks of gestation. METHODS: The study was conducted in a tertiary perinatal center and involved 38 pregnant women who had undergone amniocentesis to evaluate intrauterine infection due to preterm labor or premature rupture of membranes. The subjects were divided into three groups based on the culture results: negative (Negative Group, n = 24), positive for Mycoplasma/Ureaplasma (M/U Group, n = 6), and positive for other pathogens (Other Pathogens Group, n = 8). One-way analysis of variance was used to compare the three groups. RESULTS: The incidence of histological chorioamnionitis and neonatal sepsis was significantly different among the three groups (the Negative Group and the Other Pathogens Group, P < 0.01; the M/U Group and the Other Pathogens Group, P = 0.03). In the M/U Group, no infants had sepsis, severe intraventricular hemorrhage, cystic periventricular leukomalacia, or poor neurological outcomes, but one infant developed bronchopulmonary dysplasia and needed home oxygen treatment. Although one died of gastrorrhexis, the remaining five patients had normal brain magnetic resonance imaging findings and developed normally. CONCLUSION: The presence of Mycoplasma/Ureaplasma isolated from amniotic fluid did not cause neonatal sepsis or poor prognosis. In some infants, there was no histological chorioamnionitis in the placenta. These pathogens thus seem to be less invasive than any other microbes with respect to perinatal outcomes.

Effect of Chlamydia trachomatis on adverse pregnancy outcomes: a meta-analysis.

PURPOSE: To analyze the effect of Chlamydia trachomatis (C. trachomatis) on adverse pregnancy outcomes based on the currently available evidence. METHODS: Multiple databases were comprehensively searched from the available date of inception through December 9, 2019. The effect of C. trachomatis on adverse pregnancy outcomes was assessed using pooled odds rations (ORs) and 95% confidence intervals (CIs). Egger's test was used for publication bias. RESULTS: Fifty studies involving 502,141 participants were identified. C. trachomatis infection was found to be associated with preterm birth in antibody detection [OR (95% CI): 1.571 (1.112-2.220), P = 0.010] and high-quality assessment [OR (95% CI): 1.734 (1.295-2.321), P < 0.001], preterm premature rupture of membranes (PPROM) in culture detection [OR (95% CI): 4.339 (1.806-10.424), P = 0.001] and high-quality assessment [OR (95% CI): 2.822 (1.333-5.973), P = 0.007], stillbirth [OR (95% CI): 1.585 (1.219-2.062), P = 0.001], low-birthweight babies [OR (95% CI): 2.205 (1.137-4.274), P = 0.019], and babies small for gestational age [OR (95% CI): 1.193 (1.091-1.305), P < 0.001]. No publication bias was exhibited in miscarriage (P = 0.170), preterm birth (P = 0.303), PPROM (P = 0.341), stillbirth (P = 0.533), and low-birthweight babies (P = 0.535). CONCLUSIONS: C. trachomatis infection during pregnancy is associated with a higher risk of preterm birth, PPROM, stillbirth, low-birthweight babies, and babies small for gestational age.

Group B Streptococcus DNA Copy Numbers Measured by Digital PCR Correlates with Perinatal Outcomes.

Group B Streptococcus (GBS) is a one of the main causes of perinatal disease, yet the method for GBS detection, broth-enriched culture, is time-consuming and has low sensitivity and accuracy. We aimed to develop a GBS digital PCR (GBS-dPCR) assay for detecting GBS colonization. More rapid and accurate detection of GBS colonization could increase GBS diagnosis and treatment closer to delivery. A single-center, retrospective, case-controlled study was performed. A total of 182 rectovaginal swabs from pregnant women, who were undergoing prenatal screening by broth-enriched culture, were evaluated using GBS-dPCR targeting the cfb gene of GBS. Pregnant women with GBS colonization were followed up for correlation analysis between GBS DNA copy numbers and perinatal outcomes. The results of the GBS-dPCR assay were compared to those from the broth-enriched culture, which is the gold standard for GBS detection. The sensitivity and specificity of GBS-dPCR were 98% and 92.5%, respectively. By discrepant result analysis, the specificity of GBS-dPCR was raised to 97.4%. The incidence of premature rupture of membrane (PROM) and neonatal infection were statistically significantly positively correlated with GBS DNA copy numbers. GBS-dPCR has the advantage of directly detecting GBS colonization from swabs with high specificity and sensitivity, while reducing turnaround time (<4 h). Analysis of clinical samples with GBS-dPCR shows that GBS DNA copy numbers are positively correlated with the incidence of PROM and neonatal infection, suggesting that dPCR is a promising method for detection of GBS colonization during pregnancy.

Alloscardovia omnicolens emerging presence in premature rupture of membranes.

Alloscardovia omnicolens is a recently-reported microorganism with unknown pathogenic implications. It has been isolated in various clinical localizations but not in the endocervix. We isolated A. omnicolens in an endocervical sample from a 31-yr-old patient with preterm premature rupture of membranes (PPROM) in week 33+3 of pregnancy. The main risk of PPROM is prematurity and the possibility of developing infectious chorioamnionitis, which can be lethal for the mother and newborn. This is the first report of an association between A. omnicolens and PPROM, although its pathogenic role has not yet been elucidated.

Pathogens in preterm prelabour rupture of membranes and erythromycin for antibiotic prophylaxis: a retrospective analysis.

INTRODUCTION: Many authoritative guidelines recommend prescribing erythromycin as antibiotic prophylaxis in patients with preterm prelabour rupture of membranes (PPROM). This study evaluated the spectrum of pathogens in PPROM and assessed the effectiveness of erythromycin prophylaxis. METHODS: This retrospective study enrolled pregnant patients who were diagnosed with PPROM and who delivered at ≥24 weeks of gestation in an obstetric unit from 2013 to 2017. Pathogens isolated from maternal, placental, and neonatal specimens were analysed; their sensitivity profiles to various antibiotics were recorded. Neonatal outcomes were also evaluated. RESULTS: The overall incidence of PPROM was 2.63%. Gram-positive bacteria were cultured in 18.4% of PPROM patients (most frequent: Group B Streptococcus [GBS; 14.6%]); Gram-negative bacteria were cultured in 12.8% of PPROM patients (most frequent: Escherichia coli [8.0%]). Both Gram-positive and Gram-negative bacteria were significantly associated with early-onset neonatal sepsis (P=0.036 and P=0.001). In analyses stratified by bacterial species, E coli was significantly associated with early-onset neonatal sepsis (P=0.004), whereas GBS was not (P=0.39). Gram-positive bacteria had high rates of resistance to common antibiotics: 42.2% of GBS and 50.0% of Enterococcus and other Streptococcus bacteria were resistant to erythromycin. Escherichia coli had high rates of resistance to ampicillin (70.3%) and gentamicin (33.3%); rates of resistance to co-amoxiclav (3.6%) and intravenous cefuroxime (14.0%) were low. CONCLUSION: Gram-positive and Gram-negative bacteria were found in 29.1% of PPROM patients. Administration of erythromycin alone was insufficient to control these bacteria in 67.7% of patients with positive cultures.

Pentraxin 3 in Noninvasively Obtained Cervical Fluid Samples from Pregnancies Complicated by Preterm Prelabor Rupture of Membranes.

PROBLEM: To determine the changes of pentraxin 3 (PTX3) level in noninvasively obtained cervical fluid samples from women with preterm prelabor rupture of membranes (PPROM) based on the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI), and intra-amniotic infection (the presence of both MIAC and IAI). METHODS OF STUDY: A total of 160 women with PPROM were included. Cervical fluid samples were obtained using a Dacron polyester swab and amniotic fluid samples were obtained by transabdominal amniocentesis. Cervical fluid PTX3 levels were assessed using enzyme-linked immunosorbent assay. RESULTS: PTX3 was found in all the cervical fluid samples and its levels were higher in women with MIAC, IAI, and intra-amniotic infection than in women without these conditions. When the women were categorized into four subgroups based on the presence of MIAC and/or IAI, women with intra-amniotic infection had higher cervical fluid PTX3 levels than those with sterile IAI (IAI alone), colonization (MIAC alone), or no MIAC or IAI. A cervical fluid PTX3 level of 11 ng/mL was the best value for identifying the presence of intra-amniotic infection in women with PPROM. CONCLUSIONS: PTX3 is a constituent of cervical fluid of women with PPROM. Cervical fluid PTX3 level reflects the situation in the intra-amniotic compartments of women with PPROM. Cervical fluid PTX3 is a potential marker for the noninvasive identification of intra-amniotic infection in PPROM.

Intrapartum antibiotics for prolonged rupture of membranes at term to prevent Group B Streptococcal sepsis.

The timely administration of intrapartum antibiotic prophylaxis (IAP) to eligible pregnant mothers reduces the risk of early onset Group B Streptococcus (GBS) neonatal sepsis. The incidence of neonatal GBS sepsis is increasing, in spite of national guidelines for its prevention. This retrospective cohort study was undertaken to assess the incidence of culture-proven GBS sepsis before and after a change of practice on intrapartum management of GBS sepsis in babies born at Sunderland Royal Hospital between January 1 2008 and December 31 2017. The data regarding the risk factors, the intrapartum antibiotic prophylaxis and the outcomes of the babies were collected. Twenty-nine cases were identified and presented in two epochs-before and after changing guidelines for intrapartum management. There was a statistically significant reduction in early onset sepsis rates and no difference in late-onset sepsis rates. The prolonged rupture of membranes is a significant risk factor at any gestation. Impact statement What is already known on this subject? Appropriate intrapartum administration of antibiotics in mothers reduces 80% of early-onset GBS infections. In the United Kingdom, IAP is given based on risk factors, which fail to accurately identify and treat the woman who harbours GBS in the birth canal in labour and the incidence of GBS neonatal sepsis is increasing. The national guideline on the prevention of GBS sepsis is not consistent and is open to interpretation. What do the results of this study add? This study highlights prolonged rupture of membranes as a significant risk factor at any gestation and there were missed opportunities to prevent GBS sepsis in term babies with the prolonged rupture of membranes. This study also highlights that it is possible to reduce the neonatal GBS sepsis burden by adhering to guidelines and administering timely intrapartum antibiotics. What are the implications of these findings for clinical practice and/or further research? The timely administration of IAP to all eligible women is possible if the national guidelines are consistent and interpreted correctly. Our national guideline on the prolonged rupture of membranes at term is not clear and is interpreted differently. If IAP is provided in all those with risk factors irrespective of gestation, this would involve additional costs to the NHS; but in the long term, it will benefit as it reduces morbidity.

Lactobacillus iners-dominated vaginal microbiota in pregnancy.

OBJECTIVE: To summarize current knowledge regarding Lactobacillus iners-dominated vaginal microbiota in pregnancy, as well as an association between the presence of Lactobacillus iners and pregnancy complications Type of study: Review. SETTING: Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove. METHODS AND RESULTS: In this review, the results from literature available about the presence of L. iners-dominated microbiota in pregnancy and the association between the presence of L. iners-dominated microbiota and abortion, spontaneous preterm delivery with intact membranes, and preterm prelabor rupture of membranes are summarized. CONCLUSION: L. iners-dominated vaginal microbiota appears to be associated with an increased risk of the development of specific pregnancies pathologies.

Maternal and neonatal effects of Acinetobacter colonisation in preterm premature rupture of membrane and term labour.

INTRODUCTION: Some anecdotal reports suggest that maternal colonisation with Acinetobacter baumannii during pregnancy is associated with adverse maternal and neonatal effects, including preterm premature rupture of membrane (PPROM). The objective of this study was to compare the maternal and neonatal effects of A. baumannii colonisation in cases with PPROM and those with spontaneous onset of labour at term. METHODS: The recruitment of participants' was carried out at Selayang Hospital, Selangor, Malaysia. Vaginal swabs were prospectively taken from 104 patients of PPROM and 111 with spontaneous onset of labour at term. Swabs were also taken from the axillae and ears of their babies. These swabs were cultured to isolate A. baumannii. Maternal and neonatal adverse outcomes were documented. RESULTS: Sixteen mothers were A. baumannii positive, eight from each group respectively. None of the cases developed chorioamnionitis or sepsis. Those positive were four cases of PPROM and two babies of term labour. None of the babies developed sepsis. CONCLUSIONS: This study does not support the suggestion that A. baumannii colonisation during pregnancy is associated with adverse maternal and neonatal outcomes.

Group B streptococcus activates transcriptomic pathways related to premature birth in human extraplacental membranes in vitro.

Streptococcus agalactiae (group B streptococcus [GBS]) infection in pregnant women is the leading cause of infectious neonatal morbidity and mortality in the United States. Although inflammation during infection has been associated with preterm birth, the contribution of GBS to preterm birth is less certain. Moreover, the early mechanisms by which GBS interacts with the gestational tissue to affect adverse pregnancy outcomes are poorly understood. We hypothesized that short-term GBS inoculation activates pathways related to inflammation and premature birth in human extraplacental membranes. We tested this hypothesis using GBS-inoculated human extraplacental membranes in vitro. In agreement with our hypothesis, a microarray-based transcriptomics analysis of gene expression changes in GBS-inoculated membranes revealed that GBS activated pathways related to inflammation and preterm birth with significant gene expression changes occurring as early as 4 h postinoculation. In addition, pathways related to DNA replication and repair were downregulated with GBS treatment. Conclusions based on our transcriptomics data were further supported by responses of prostaglandin E2 (PGE2), and matrix metalloproteinases 1 (MMP1) and 3 (MMP3), all of which are known to be involved in parturition and premature rupture of membranes. These results support our initial hypothesis and provide new information on molecular targets of GBS infection in human extraplacental membranes.

Membrane Vesicles of Group B Streptococcus Disrupt Feto-Maternal Barrier Leading to Preterm Birth.

Infection of the genitourinary tract with Group B Streptococcus (GBS), an opportunistic gram positive pathogen, is associated with premature rupture of amniotic membrane and preterm birth. In this work, we demonstrate that GBS produces membrane vesicles (MVs) in a serotype independent manner. These MVs are loaded with virulence factors including extracellular matrix degrading proteases and pore forming toxins. Mice chorio-decidual membranes challenged with MVs ex vivo resulted in extensive collagen degradation leading to loss of stiffness and mechanical weakening. MVs when instilled vaginally are capable of anterograde transport in mouse reproductive tract. Intra-amniotic injections of GBS MVs in mice led to upregulation of pro-inflammatory cytokines and inflammation mimicking features of chorio-amnionitis; it also led to apoptosis in the chorio-decidual tissue. Instillation of MVs in the amniotic sac also resulted in intrauterine fetal death and preterm delivery. Our findings suggest that GBS MVs can independently orchestrate events at the feto-maternal interface causing chorio-amnionitis and membrane damage leading to preterm birth or fetal death.

Infection-induced thrombin production: a potential novel mechanism for preterm premature rupture of membranes (PPROM).

BACKGROUND: Preterm premature rupture of membranes is a leading contributor to maternal and neonatal morbidity and death. Epidemiologic and experimental studies have demonstrated that thrombin causes fetal membrane weakening and subsequently preterm premature rupture of membranes. Although blood is suspected to be the likely source of thrombin in fetal membranes and amniotic fluid of patients with preterm premature rupture of membranes, this has not been proved. Ureaplasma parvum is emerging as a pathogen involved in prematurity, which includes preterm premature rupture of membranes; however, until now, prothrombin production that has been induced directly by bacteria in fetal membranes has not been described. OBJECTIVE: This study was designed to investigate whether Ureaplasma parvum exposure can induce prothrombin production in fetal membranes cells. STUDY DESIGN: Primary fetal membrane cells (amnion epithelial, chorion trophoblast, and decidua stromal) or full-thickness fetal membrane tissue explants from elective, term, uncomplicated cesarean deliveries were harvested. Cells or tissue explants were infected with live Ureaplasma parvum (1×105, 1×106 or 1×107 colony-forming units per milliliter) or lipopolysaccharide (Escherichia coli J5, L-5014; Sigma Chemical Company, St. Louis, MO; 100 ng/mL or 1000 ng/mL) for 24 hours. Tissue explants were fixed for immunohistochemistry staining of thrombin/prothrombin. Fetal membrane cells were fixed for confocal immunofluorescent staining of the biomarkers of fetal membrane cell types and thrombin/prothrombin. Protein and messenger RNA were harvested from the cells and tissue explants for Western blot or quantitative reverse transcription polymerase chain reaction to quantify thrombin/prothrombin protein or messenger RNA production, respectively. Data are presented as mean values ± standard errors of mean. Data were analyzed using 1-way analysis of variance with post hoc Dunnett's test. RESULTS: Prothrombin production and localization were confirmed by Western blot and immunostainings in all primary fetal membrane cells and tissue explants. Immunofluorescence observations revealed a perinuclear localization of prothrombin in amnion epithelial cells. Localization of prothrombin in chorion and decidua cells was perinuclear and cytoplasmic. Prothrombin messenger RNA and protein expression in fetal membranes were increased significantly by Ureaplasma parvum, but not lipopolysaccharide, treatments in a dose-dependent manner. Specifically, Ureaplasma parvum at a dose of 1×107 colony-forming units/mL significantly increased both prothrombin messenger RNA (fold changes in amnion: 4.1±1.9; chorion: 5.7±4.2; decidua: 10.0±5.4; fetal membrane: 9.2±3.0) and protein expression (fold changes in amnion: 138.0±44.0; chorion: 139.6±15.1; decidua: 56.9±29.1; fetal membrane: 133.1±40.0) compared with untreated control subjects. Ureaplasma parvum at a dose of 1×106 colony-forming units/mL significantly up-regulated prothrombin protein expression in chorion cells (fold change: 54.9±5.3) and prothrombin messenger RNA expression in decidua cells (fold change: 4.4±1.9). CONCLUSION: Our results demonstrate that prothrombin can be produced directly by fetal membrane amnion, chorion, and decidua cells. Further, prothrombin production can be stimulated by Ureaplasma parvum exposure in fetal membranes. These findings represent a potential novel underlying mechanism of Ureaplasma parvum-induced rupture of fetal membranes.

Late preterm prelabor rupture of fetal membranes: fetal inflammatory response and neonatal outcome.

BackgroundTo characterize the influence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI) on the intensity of the fetal inflammatory response and the association between the presence of the fetal inflammatory response syndrome (FIRS) and short-term neonatal morbidity in the preterm prelabor rupture of membranes (PPROM) between the gestational ages of 34 and 37 weeks.MethodsOne hundred and fifty-nine women were included in the study. The umbilical cord blood interleukin (IL)-6 concentrations were determined using enzyme-linked immunosorbent assay kits. FIRS was defined based on the umbilical cord blood IL-6 concentration and the presence of funisitis and/or chorionic plate vasculitis.ResultsWomen with both MIAC and IAI had the highest median umbilical cord blood IL-6 concentrations and highest rates of FIRS. Women with FIRS had the higher rates of early-onset sepsis and intraventricular hemorrhage grades I and II when FIRS was characterized based on the umbilical cord blood IL-6 concentrations and the histopathological findings.ConclusionThe presence of both MIAC and IAI was associated with a higher fetal inflammatory response and a higher rate of FIRS. Different aspects of short-term neonatal morbidity were related to FIRS when defined by umbilical cord blood IL-6 concentrations and the histopathology of the placenta.