A sonographic short cervix as the only clinical manifestation of intra-amniotic infection

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

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

Antibiotic administration reduced intra-amniotic inflammation 7 days after preterm premature rupture of the membranes with intra-amniotic infection

OBJECTIVE

Intra-amniotic infections increase the risk of preterm delivery and short- and long-term fetal morbidity; however, no consensus exists on the choice of antimicrobial agents as treatment for these infections. We aimed to examine the efficacy of intravenous administration of sulbactam/ampicillin (SBT/ABPC) and azithromycin (AZM) for intra-amniotic infection in patients with preterm premature rupture of membranes (PPROM).

METHODS

This study followed a single-centered retrospective cohort design. We compared changes in interleukin 6 (IL-6) levels and the load of Ureaplasma species DNA in the amniotic fluid between singleton pregnancy patients with intra-amniotic infection (Group A) and without either intra-amniotic inflammation (IAI) or microbial invasion of the amniotic cavity (MIAC) (Group B) who developed PPROM between week 22, day 0 and week 33, day 6 of gestation and maintained pregnancy for ≥7 d after diagnosis (August 2014 to April 2020). Patients in Group A were treated with SBT/ABPC and AZM, whereas those in Group B were treated with ABPC and AZM or clarithromycin.

RESULTS

Thirty-one patients with IAI and 48 patients without either IAI or MIAC at diagnosis of PPROM underwent pregnancy/delivery management at our hospital. Following the study population selection, we evaluated six patients in Group A and 13 patients in Group B. Amniotic fluid IL-6 concentrations at the initial amniocentesis were high, ranging from 11.7 ng/mL to 139.2 ng/mL, indicating a state of severe IAI in all six patients in Group A. In five of the six patients in Group A, the amniotic fluid cultures during the first amniocentesis included Ureaplasma species only. In both groups, the amniotic fluid IL-6 concentration at the follow-up amniocentesis was lower than that at the initial amniocentesis (Group A: follow-up median 3.06 ng/mL [quartiles, 1.75-6.74], initial median 30.53 ng/mL [quartiles, 15.60-67.07], p＝.03; Group B: follow-up median 0.40 ng/mL [quartiles, 0.18-0.69], initial median 0.96 ng/mL [quartiles, 0.65-1.42], p＝.005); Group A showed a greater decrease than Group B (p < .001). No difference was found between the microbial loads of Ureaplasma species DNA in the initial and follow-up amniocentesis (p = .13).

CONCLUSIONS

In patients with PPROM and intra-amniotic infection, IL-6 levels in the amniotic fluid decreased significantly from before antimicrobial administration to day 7. This decrease is thought to be mainly due to the effects of intravenous AZM. The efficacy of AZM in patients with PPROM needs to be further confirmed via randomized controlled studies in the future.

Longitudinal change in cervical length following vaginal or abdominal cervical cerclage: a randomized comparison

BACKGROUND

Cervical cerclage has been shown to reduce the risk of recurrent spontaneous preterm birth in a high-risk patient population; however, the mechanism is not well understood. Transabdominal cerclage is superior to low and high vaginal cerclage in reducing early spontaneous preterm birth and fetal loss in women with previous failed vaginal cerclage. Cervical length measurements are commonly used to monitor high-risk women and may explain the mechanism of success.

OBJECTIVE

This study aimed to evaluate the rate of change in longitudinal cervical length after randomized placement of low transvaginal, high transvaginal, or transabdominal cerclage in women with a previous failed vaginal cerclage.

STUDY DESIGN

This was a planned analysis of longitudinal transvaginal ultrasound cervical length measurements from patients enrolled in the Vaginal Randomised Intervention of Cerclage trial, a randomized controlled trial comparing transabdominal cerclage or high transvaginal cerclage with low transvaginal cerclage. Cervical length measurements at specific gestational ages were compared over time and between groups, using generalized estimating equations fitted using the maximum-likelihood random-effects estimator. In addition, cervical length measurements were compared in women with transabdominal cerclage placed before and during pregnancy. The diagnostic accuracy of cervical length as a predictor of spontaneous preterm birth at <32 weeks of gestation was explored.

RESULTS

This study included 78 women who underwent longitudinal cervical length assessment (70% of the analyzed cohort) with a history of failed cerclage, of whom 25 (32%) were randomized to low transvaginal cerclage, 26 (33%) to high transvaginal cerclage, and 27 (35%) to transabdominal cerclage. Abdominal cerclage was superior to low (P=.008) and high (P=.001) vaginal cerclage at maintaining cervical length over the surveillance period (14 to 26 weeks of gestation) (+0.08 mm/week, 95% confidence interval, -0.40 to 0.22; P=.580). On average, the cervical length was 1.8 mm longer by the end of the 12-week surveillance period in women with transabdominal cerclage (+1.8 mm; 95% confidence interval, -7.89 to 4.30; P=.564). High vaginal cerclage was no better than low cervical cerclage in the prevention of cervical shortening; the cervix shortened by 13.2 mm over 12 weeks in those with low vaginal cerclage (95% confidence interval, -21.7 to -4.7; P=.002) and by 20 mm over 12 weeks in those with high vaginal cerclage (95% confidence interval, -33.1 to -7.4; P=.002). Preconception transabdominal cerclage resulted in a longer cervix than those performed during pregnancy; this difference was significant after 22 weeks of gestation (48.5 mm vs 39.6 mm; P=.039). Overall, cervical length was an excellent predictor of spontaneous preterm birth at <32 weeks of gestation (receiver operating characteristic curve, 0.92; 95% confidence interval, 0.82-1.00).

CONCLUSION

In women with a previous failed cervical cerclage, in the next pregnancy, the cervical length in women treated with vaginal cerclage funneled and shortened over time, whereas there was preservation of cervical length in women who receive transabdominal cerclage. Cervical length remained longer in transabdominal procedures performed before pregnancy than in transabdominal procedures performed during pregnancy. Overall, cervical length was an excellent predictor of spontaneous preterm birth in our cohort. Our findings may explain the mechanism of benefit for transabdominal cerclage, with its high placement better maintaining the structural integrity of the cervix at the level of the internal os.

Cervicovaginal mucus barrier properties during pregnancy are impacted by the vaginal microbiome

Introduction

Mucus in the female reproductive tract acts as a barrier that traps and eliminates pathogens and foreign particles via steric and adhesive interactions. During pregnancy, mucus protects the uterine environment from ascension of pathogens and bacteria from the vagina into the uterus, a potential contributor to intrauterine inflammation and preterm birth. As recent work has demonstrated the benefit of vaginal drug delivery in treating women's health indications, we sought to define the barrier properties of human cervicovaginal mucus (CVM) during pregnancy to inform the design of vaginally delivered therapeutics during pregnancy.

Methods

CVM samples were self-collected by pregnant participants over the course of pregnancy, and barrier properties were quantified using multiple particle tracking. 16S rRNA gene sequencing was performed to analyze the composition of the vaginal microbiome.

Results

Participant demographics differed between term delivery and preterm delivery cohorts, with Black or African American participants being significantly more likely to delivery prematurely. We observed that vaginal microbiota is most predictive of CVM barrier properties and of timing of parturition. Lactobacillus crispatus dominated CVM samples showed increased barrier properties compared to polymicrobial CVM samples.

Discussion

This work informs our understanding of how infections occur during pregnancy, and directs the engineering of targeted drug treatments for indications during pregnancy.

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.

Management of Pregnancy with Cervical Shortening: Real-Life Clinical Challenges

Background and Objectives: Preterm birth is the leading cause of neonatal mortality worldwide and may be responsible for lifelong morbidities in the survivors. Cervical shortening is one of the common pathways to preterm birth associated with its own diagnostic and management challenges. The preventive modalities that have been tested include progesterone supplementation and cervical cerclage and pessaries. The study aimed to assess the management strategies and outcomes in a group of patients with a short cervix during pregnancy or cervical insufficiency. Materials and Methods: Seventy patients from the Riga Maternity Hospital in Riga, Latvia, were included in the prospective longitudinal cohort study between 2017 and 2021. Patients were treated with progesterone, cerclage, and/or pessaries. The signs of intra-amniotic infection/inflammation were assessed, and antibacterial therapy was given when the signs were positive. Results: The rates of PTB were 43.6% (n = 17), 45.5% (n = 5), 61.1% (n = 11), and 50.0% (n = 1) in progesterone only, cerclage, pessary, and cerclage plus pesssary groups, respectively. The progesterone therapy was associated with a reduced preterm birth risk (x2(1) = 6.937, p = 0.008)), whereas positive signs of intra-amniotic infection/inflammation significantly predicted the risk of preterm birth (p = 0.005, OR = 3.82, 95% [CI 1.31–11.11]). Conclusions: A short cervix and bulging membranes, both indicators of intra-amniotic infection/inflammation, are the key risk factors in preterm birth risk predictions. Progesterone supplementation should remain at the forefront of preterm birth prevention. Among patients with a short cervix and especially complex anamnesis, the preterm rates remain high. The successful management of patients with cervical shortening lies between the consensus-based approach for screening, follow-up, and treatment on the one side and personalising medical therapy on the other.

Effect of preoperative low-normal cervical length on perinatal outcome after laparotomy-assisted fetoscopic spina bifida repair

OBJECTIVE

To determine if preoperative cervical length in the low-normal range increases the risk of adverse perinatal outcome in patients undergoing fetoscopic spina bifida repair.

METHODS

This was a retrospective cohort study of patients who underwent fetal spina bifida repair between September 2014 and May 2022 at a single center. Cervical length was measured on transvaginal ultrasound during the week before surgery. Eligibility for laparotomy-assisted fetoscopic spina bifida repair was as per the criteria of the Management of Myelomeningocele Study, although maternal body mass index (BMI) up to 40 kg/m² was allowed. Laparotomy-assisted fetoscopic spina bifida repair was performed, with carbon dioxide insufflation via two 12-French ports in the exteriorized uterus. All patients received the same peri- and postoperative tocolysis regimen, including magnesium sulfate, nifedipine and indomethacin. Postoperative follow-up ultrasound scans were performed either weekly (< 32 weeks' gestation) or twice a week (≥ 32 weeks). Perinatal outcome was compared between patients with a preoperative cervical length of 25-30 mm vs those with a cervical length > 30 mm. Logistic regression analyses and generalized linear mixed regression analyses were used to predict delivery at less than 30, 34 and 37 weeks' gestation.

RESULTS

The study included 99 patients with a preoperative cervical length > 30 mm and 12 patients with a cervix 25-30 mm in length. One further case which underwent spina bifida repair was excluded because cervical length was measured > 1 week before surgery. No differences in maternal demographics, gestational age (GA) at surgery, duration of surgery or duration of carbon dioxide uterine insufflation were observed between groups. Cases with low-normal cervical length had an earlier GA at delivery (median (range), 35.2 (25.1-39.7) weeks vs 38.2 (26.0-40.9) weeks; P = 0.01), higher rates of delivery at < 34 weeks (41.7% vs 10.2%; P = 0.01) and < 30 weeks (25.0% vs 1.0%; P < 0.01) and a higher rate of preterm prelabor rupture of membranes (PPROM) (58.3% vs 26.3%; P = 0.04) at an earlier GA (mean ± SD, 29.3 ± 4.0 weeks vs 33.0 ± 2.4 weeks; P = 0.05) compared to those with a normal cervical length. Neonates of cases with low-normal cervical length had a longer stay in the neonatal intensive care unit (20 (7-162) days vs 9 (3-253) days; P = 0.02) and higher rates of respiratory distress syndrome (50.0% vs 14.4%; P < 0.01), sepsis (16.7% vs 1.0%; P = 0.03), necrotizing enterocolitis (16.7% vs 0%; P = 0.01) and retinopathy (33.3% vs 1.0%; P < 0.01). There was an association between preoperative cervical length and risk of delivery at < 30 weeks which was significant only for patients with a maternal BMI < 25 kg/m² (odds ratio, 0.37 (95% CI, 0.07-0.81); P = 0.02).

CONCLUSIONS

Low-normal cervical length (25-30 mm) as measured before in-utero laparotomy-assisted fetoscopic spina bifida repair may increase the risk of adverse perinatal outcomes, including PPROM and preterm birth, leading to higher rates of neonatal complications. These data warrant further research and are of critical relevance for clinical teams considering the eligibility of patients for in-utero spina bifida repair. Based on this evidence, patients with a low-normal cervical length should be aware of their increased risk for adverse perinatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

An enlarged fetal thymus may be the initial response to intrauterine inflammation in pregnant women at risk for preterm birth

OBJECTIVE

Fetal thymus involvement in prematurity has been studied, and this study aimed to evaluate its relationship with short cervix and amniotic fluid sludge in the second trimester of pregnancy.

METHODS

In this prospective cross-sectional study, 79 pregnant women (19+0 to 24+6 weeks) were included, and cervical length and the presence or absence of amniotic fluid sludge were evaluated. In the three-vessel view of the fetal thorax, the thymus was identified, and its perimeter and transverse diameter were measured and transformed to a zeta score based on gestational age.

RESULTS

Data from 22 women with short cervix (<25 mm) and 57 patients with normal cervix (≥25 mm) were analyzed. The transverse diameter of the fetal thymus was significantly greater in the short cervix group compared to that of the normal cervix group (z-score 2.708 vs. -0.043, p=0.003). There were no significant differences in the perimeter (z-score -0.039 vs. -0.071, p=0.890) or the transverse diameter (z-score 1.297 vs. -0.004, p=0.091) of the fetal thymus associated with the presence (n=21) or absence of sludge (n=58).

CONCLUSION

A short cervix is associated with an increased transverse diameter of the fetal thymus during the second trimester of gestation.

The role of intraamniotic inflammation in threatened midtrimester miscarriage

BACKGROUND

The assessment and management of patients with threatened midtrimester miscarriage is a clinical challenge because the etiology of this condition is poorly understood.

OBJECTIVE

This study aimed to examine the frequency of intraamniotic infection or inflammation and the effect of antibiotics in patients presenting with regular uterine contractions and intact membranes before 20 weeks of gestation.

STUDY DESIGN

This retrospective study comprised patients who met the following criteria: (1) singleton gestation, (2) gestational age before 20 weeks, (3) the presence of regular uterine contractions confirmed by a tocodynamometer (8 or more contractions in 60 minutes), (4) intact amniotic membranes, and (5) transabdominal amniocentesis performed for the evaluation of the microbiologic and inflammatory status of the amniotic cavity. Samples of amniotic fluid were cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction was performed to detect Ureaplasma species. Amniotic fluid was tested for white blood cell counts and matrix metalloproteinase-8 concentrations to diagnose intraamniotic inflammation. Patients with intraamniotic inflammation, or intraamniotic infection, were treated with antibiotics (a combination of ceftriaxone, clarithromycin, and metronidazole). Treatment success was defined as the resolution of intraamniotic infection/inflammation at the follow-up amniocentesis or delivery after 34 weeks of gestation.

RESULTS

1) Intraamniotic inflammation was present in 88% (15/17) of patients, whereas infection was detectable in only 2 cases; 2) objective evidence of resolution of intraamniotic inflammation after antibiotic treatment was demonstrated in 100% (4/4) of patients who underwent a follow-up amniocentesis; 3) 30% (5/15) of women receiving antibiotics delivered after 34 weeks of gestation (3 of the 5 patients had a negative follow-up amniocentesis, and 2 of the women were without a follow-up amniocentesis); 4) the overall treatment success of antibiotics was 40% (6/15; 4 cases of objective evidence of resolution of intra-amniotic inflammation and 5 cases of delivery after 34 weeks of gestation).

CONCLUSION

The prevalence of intraamniotic inflammation in patients who presented with a threatened midtrimester miscarriage was 88% (15/17), and, in most cases, microorganisms could not be detected. Antibiotic treatment, administered to patients with intraamniotic inflammation, was associated with either objective resolution of intraamniotic inflammation or delivery after 34 weeks of gestation in 40% (6/15) of the cases.

Characterization of amniotic fluid sludge in preterm and term gestations

OBJECTIVE

To describe the characteristics of amniotic fluid sludge obtained from patients in term and preterm gestations.

METHODS

This cross-sectional study included patients with dense aggregates of particulate matter detected in amniotic fluid, observed with transvaginal sonography. All patients were in labor and had an impending delivery, either preterm or at term. Echogenic material contained within amniotic fluid was retrieved transvaginally by needle amniotomy under direct visualization. The amniotic fluid analysis consisted of a Gram stain, cultures for aerobic/anaerobic bacteria and genital mycoplasmas, and a white blood cell count.

RESULTS

Twenty-five patients ranging from 18 to 41 weeks of gestation were included in the study. We observed the following: (1) the appearance of amniotic fluid was consistent with pus-like material, vernix, or meconium by naked eye examination; (2) samples collected before 33 weeks of gestation (n = 13) had a pus-like appearance; however, after this gestational age, most of the samples [83% (10/12)] appeared to be consistent with vernix; (3) amniotic fluid cultures were positive for microorganisms in 13 patients, of which 10 were preterm gestations before 33 weeks; (4) the most frequent microorganisms retrieved by culture were genital mycoplasmas (Ureaplasma urealyticum [46% (6/13)]), followed by Mycoplasma hominis [31% (4/13)] and Candida albicans [15% (2/13)]; and (5) patients with sonographic particulate matter in preterm gestations frequently presented acute histologic chorioamnionitis and funisitis, but these conditions were rare in patients at term.

CONCLUSION

The nature of amniotic fluid particulate material varies as a function of gestational age. The material obtained in preterm gestations is frequently related to an inflammatory process, while that obtained at term is often consistent with vernix and appears to represent a maturational process.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Resolution of acute cervical insufficiency after antibiotics in a case with amniotic fluid sludge

Cervical insufficiency generally refers to a condition in which there is mid-trimester cervical dilatation or protruding chorioamniotic membranes in the absence of uterine contractions. Such condition is a risk factor for spontaneous mid-trimester abortion or early preterm birth, and is associated with adverse neonatal outcomes. Both intra-amniotic infection and inflammation ascertained by amniocentesis have been identified in patients with cervical insufficiency, and are poor prognostic factors. A subset of patients with intra-amniotic inflammation will have no demonstrable microorganisms detected via cultivation or molecular methods, and therefore represent cases of sterile intra-amniotic inflammation. Amniotic fluid sludge (free-floating hyperechogenic material within the amniotic fluid in close proximity to the uterine cervix) identified on sonography is a biomarker for intra-amniotic infection and inflammation. Recent evidence suggests that intra-amniotic infection, as well as sterile intra-amniotic inflammation can be treated successfully using antimicrobial agents. We report a unique case in which administration of antibiotics in the presence of mid-trimester cervical insufficiency, sterile intra-amniotic inflammation, and amniotic fluid sludge was associated with resolution of the cervical findings, as demonstrated on both sonographic and speculum examination. The patient successfully underwent elective cesarean delivery at 36-2/7 weeks of gestation. This case illustrates that antibiotic therapy may be effective despite the presence of several high-risk pregnancy conditions, and that successful outcome is possible.

The amniotic fluid proteome predicts imminent preterm delivery in asymptomatic women with a short cervix

Preterm birth, the leading cause of perinatal morbidity and mortality, is associated with increased risk of short- and long-term adverse outcomes. For women identified as at risk for preterm birth attributable to a sonographic short cervix, the determination of imminent delivery is crucial for patient management. The current study aimed to identify amniotic fluid (AF) proteins that could predict imminent delivery in asymptomatic patients with a short cervix. This retrospective cohort study included women enrolled between May 2002 and September 2015 who were diagnosed with a sonographic short cervix (< 25 mm) at 16-32 weeks of gestation. Amniocenteses were performed to exclude intra-amniotic infection; none of the women included had clinical signs of infection or labor at the time of amniocentesis. An aptamer-based multiplex platform was used to profile 1310 AF proteins, and the differential protein abundance between women who delivered within two weeks from amniocentesis, and those who did not, was determined. The analysis included adjustment for quantitative cervical length and control of the false-positive rate at 10%. The area under the receiver operating characteristic curve was calculated to determine whether protein abundance in combination with cervical length improved the prediction of imminent preterm delivery as compared to cervical length alone. Of the 1,310 proteins profiled in AF, 17 were differentially abundant in women destined to deliver within two weeks of amniocentesis independently of the cervical length (adjusted p-value < 0.10). The decreased abundance of SNAP25 and the increased abundance of GPI, PTPN11, OLR1, ENO1, GAPDH, CHI3L1, RETN, CSF3, LCN2, CXCL1, CXCL8, PGLYRP1, LDHB, IL6, MMP8, and PRTN3 were associated with an increased risk of imminent delivery (odds ratio > 1.5 for each). The sensitivity at a 10% false-positive rate for the prediction of imminent delivery by a quantitative cervical length alone was 38%, yet it increased to 79% when combined with the abundance of four AF proteins (CXCL8, SNAP25, PTPN11, and MMP8). Neutrophil-mediated immunity, neutrophil activation, granulocyte activation, myeloid leukocyte activation, and myeloid leukocyte-mediated immunity were biological processes impacted by protein dysregulation in women destined to deliver within two weeks of diagnosis. The combination of AF protein abundance and quantitative cervical length improves prediction of the timing of delivery compared to cervical length alone, among women with a sonographic short cervix.

The role of the placenta in spontaneous preterm labor and delivery with intact membranes

OBJECTIVES

To determine whether placental vascular pathology and impaired placental exchange due to maturational defects are involved in the etiology of spontaneous preterm labor and delivery in cases without histologic acute chorioamnionitis.

METHODS

This was a retrospective, observational study. Cases included pregnancies that resulted in spontaneous preterm labor and delivery (<37 weeks), whereas uncomplicated pregnancies that delivered fetuses at term (≥37-42 weeks of gestation) were selected as controls. Placental histological diagnoses were classified into three groups: lesions of maternal vascular malperfusion, lesions of fetal vascular malperfusion, and placental microvasculopathy, and the frequency of each type of lesion in cases and controls was compared. Moreover, we specifically searched for villous maturational abnormalities in cases and controls. Doppler velocimetry of the umbilical and uterine arteries were performed in a subset of patients.

RESULTS

There were 184 cases and 2471 controls, of which 95 and 1178 had Doppler studies, respectively. The frequency of lesions of maternal vascular malperfusion was greater in the placentas of patients with preterm labor than in the control group [14.1% (26/184) vs. 8.8% (217/2471) (p=0.023)]. Disorders of villous maturation were more frequent in the group with preterm labor than in the control group: 41.1% (39/95) [delayed villous maturation in 31.6% (30/95) vs. 2.5% (13/519) in controls and accelerated villous maturation in 9.5% (9/95) vs. none in controls].

CONCLUSIONS

Maturational defects of placental villi were associated with approximately 41% of cases of unexplained spontaneous preterm labor and delivery without acute inflammatory lesions of the placenta and with delivery of appropriate-for-gestational-age fetuses.

The immunobiology of preterm labor and birth: intra-amniotic inflammation or breakdown of maternal-fetal homeostasis

In brief

The syndrome of preterm labor comprises multiple established and novel etiologies. This review summarizes the distinct immune mechanisms implicated in preterm labor and birth and highlights potential strategies for its prevention.

Abstract

Preterm birth, the leading cause of neonatal morbidity and mortality worldwide, results from preterm labor, a syndrome that includes multiple etiologies. In this review, we have summarized the immune mechanisms implicated in intra-amniotic inflammation, the best-characterized cause of preterm labor and birth, as well as novel etiologies non-associated with intra-amniotic inflammation (i.e. formally known as idiopathic). While the intra-amniotic inflammatory responses driven by microbes (infection) or alarmins (sterile) have some overlap in the participating cellular and molecular processes, the distinct natures of these two conditions necessitate the implementation of specific approaches to prevent adverse pregnancy and neonatal outcomes. Intra-amniotic infection can be treated with the correct antibiotics, whereas sterile intra-amniotic inflammation could potentially be treated by administering a combination of anti-inflammatory drugs (e.g. betamethasone, inflammasome inhibitors, etc.). Recent evidence also supports the role of fetal T-cell activation as a newly described trigger for preterm labor and birth in a subset of cases diagnosed as idiopathic. Moreover, herein we also provide evidence of two maternally-driven immune mechanisms responsible for preterm births formerly considered to be idiopathic. First, the impairment of maternal Tregs can lead to preterm birth, likely due to the loss of immunosuppressive activity resulting in unleashed effector T-cell responses. Secondly, homeostatic macrophages were shown to be essential for maintaining pregnancy and promoting fetal development, and the adoptive transfer of homeostatic M2-polarized macrophages shows great promise for preventing inflammation-induced preterm birth. Collectively, in this review, we discuss the established and novel immune mechanisms responsible for preterm birth and highlight the potential targets for novel strategies aimed at preventing the multi-etiological syndrome of preterm labor leading to preterm birth.

Ureaplasma and Prevotella colonization with Lactobacillus abundance during pregnancy facilitates term birth

Ureaplasma and Prevotella infections are well-known bacteria associated with preterm birth. However, with the development of metagenome sequencing techniques, it has been found that not all Ureaplasma and Prevotella colonizations cause preterm birth. The purpose of this study was to determine the association between Ureaplasma and Prevotella colonization with the induction of preterm birth even in the presence of Lactobacillus. In this matched case–control study, a total of 203 pregnant Korean women were selected and their cervicovaginal fluid samples were collected during mid-pregnancy. The microbiome profiles of the cervicovaginal fluid were analyzed using 16S rRNA gene amplification. Sequencing data were processed using QIIME1.9.1. Statistical analyses were performed using R software, and microbiome analysis was performed using the MicrobiomeAnalyst and Calypso software. A positive correlation between Ureaplasma and other genera was highly related to preterm birth, but interestingly, there was a negative correlation with Lactobacillus and term birth, with the same pattern observed with Prevotella. Ureaplasma and Prevotella colonization with Lactobacillus abundance during pregnancy facilitates term birth, although Ureaplasma and Prevotella are associated with preterm birth. Balanced colonization between Lactobacillus and Ureaplasma and Prevotella is important to prevent preterm birth.

Antibody microarray analysis of amniotic fluid proteomes in women with cervical insufficiency and short cervix, and their association with pregnancy latency length

Introduction

This study aimed to investigate amniotic fluid (AF) proteins that were differentially expressed between patients with cervical insufficiency (CI) and asymptomatic short cervix (SCX, ≤ 25 mm), and whether these proteins could be predictive of spontaneous preterm birth (SPTB) in these patients.

Method

This was a retrospective cohort study of 129 singleton pregnant women with CI (n = 80) or SCX (n = 49) at 17 to 26 weeks who underwent amniocentesis. An antibody microarray was used to perform comparative proteomic profiling of AF from matched CI (n = 20) and SCX (n = 20) pregnancies. In the total cohort, an ELISA validation study was performed for 15 candidate proteins of interest. Subgroup analyses of patients with CI and SCX were conducted to evaluate the association between the 15 proteins and SPTB at < 32 weeks of gestation.

Results

Eighty-six proteins showed intergroup differences. ELISA validation confirmed significantly higher levels of AF EN-RAGE, IL-8, lipocalin-2, MMP-9, S100A8/A9, thrombospondin-2, and TNFR2 in patients with CI than in those with SCX. Multivariable analysis showed that increased AF levels of EN-RAGE, S100A8/A9, and uPA were independently associated with SPTB at < 32 weeks in patients with CI; whereas in patients with SCX, high AF levels of APRIL, EN-RAGE, LBP, and TNFR2 were independently associated with SPTB at < 32 weeks.

Conclusions

Multiple AF proteins show altered expression in patients with CI compared with SCX controls. Moreover, several novel mediators involved in inflammation were identified as potential biomarkers for predicting SPTB after the diagnosis of CI and SCX. These results provide new insights into target-specific molecules for targeted therapies to prevent SPTB in patients with CI/SCX.

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.

Longitudinal evaluation of azithromycin and cytokine concentrations in amniotic fluid following one-time oral dosing in pregnancy

To utilize noninvasive collection of amniotic fluid in the setting of preterm premature rupture of membranes (PPROMs) to report the time concentration profile of azithromycin in amniotic fluid over 7 days from a single dose, and evaluate the correlation between azithromycin concentration and inflammatory markers in amniotic fluid. Prospective cohort study of five pregnant patients admitted with PPROMs and treated with a single 1 g oral azithromycin dose. Amniotic fluid was collected from pads and used to quantify azithromycin concentration as well as TNFa, IL-1a, IL-1b, IL-6, IL-8, and IL-10 concentrations. Primary outcome was time/concentration profile of azithromycin in amniotic fluid. Secondary outcome included correlation between azithromycin concentration and cytokine concentrations. Five patients were enrolled. Mean gestational age on admission with PPROM was 27.5 ± 2.3 weeks with a median latency of 7 days (interquartile range [IQR] = 4-13). A median of two samples/day (IQR = 1-3) were collected per participant. Azithromycin was quantified in duplicate; intra-assay coefficient of variation was 17%. Azithromycin concentration was less than 60 ng/ml after day 3. Azithromycin concentration was positively correlated with IL-8 (r = 0.38, p = 0.03), IL1a (r = 0.39, p = 0.03), and IL-1b (r = 0.36, p = 0.04) in amniotic fluid. Azithromycin is detectable in amniotic fluid over 7 days from a single 1 g maternal dose, however, it is not sustained over the range of minimum inhibitory concentration for common genitourinary flora. Based on correlation with specific cytokines, azithromycin penetration in amniotic fluid may relate to maternal monocyte concentration in amniotic fluid in the setting of PPROM.

Next generation strategies for preventing preterm birth

Preterm birth (PTB) is defined as delivery before 37 weeks of gestation. Globally, 15 million infants are born prematurely, putting these children at an increased risk of mortality and lifelong health challenges. Currently in the U.S., there is only one FDA approved therapy for the prevention of preterm birth. Makena is an intramuscular progestin injection given to women who have experienced a premature delivery in the past. Recently, however, Makena failed a confirmatory trial, resulting the Center for Drug Evaluation and Research's (CDER) recommendation for the FDA to withdrawal Makena's approval. This recommendation would leave clinicians with no therapeutic options for preventing PTB. Here, we outline recent interdisciplinary efforts involving physicians, pharmacologists, biologists, chemists, and engineers to understand risk factors associated with PTB, to define mechanisms that contribute to PTB, and to develop next generation therapies for preventing PTB. These advances have the potential to better identify women at risk for PTB, prevent the onset of premature labor, and, ultimately, save infant lives.

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

OBJECTIVES

Clinical chorioamnionitis at term is considered the most common infection-related diagnosis in labor and delivery units worldwide. The syndrome affects 5-12% of all term pregnancies and is a leading cause of maternal morbidity and mortality as well as neonatal death and sepsis. The objectives of this study were to determine the (1) amniotic fluid microbiology using cultivation and molecular microbiologic techniques; (2) diagnostic accuracy of the clinical criteria used to identify patients with intra-amniotic infection; (3) relationship between acute inflammatory lesions of the placenta (maternal and fetal inflammatory responses) and amniotic fluid microbiology and inflammatory markers; and (4) frequency of neonatal bacteremia.

METHODS

This retrospective cross-sectional study included 43 women with the diagnosis of clinical chorioamnionitis at term. The presence of microorganisms in the amniotic cavity was determined through the analysis of amniotic fluid samples by cultivation for aerobes, anaerobes, and genital mycoplasmas. A broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry was also used to detect bacteria, select viruses, and fungi. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin-6 (IL-6) concentration ≥2.6 ng/mL.

RESULTS

(1) Intra-amniotic infection (defined as the combination of microorganisms detected in amniotic fluid and an elevated IL-6 concentration) was present in 63% (27/43) of cases; (2) the most common microorganisms found in the amniotic fluid samples were Ureaplasma species, followed by Gardnerella vaginalis; (3) sterile intra-amniotic inflammation (elevated IL-6 in amniotic fluid but without detectable microorganisms) was present in 5% (2/43) of cases; (4) 26% of patients with the diagnosis of clinical chorioamnionitis had no evidence of intra-amniotic infection or intra-amniotic inflammation; (5) intra-amniotic infection was more common when the membranes were ruptured than when they were intact (78% [21/27] vs. 38% [6/16]; p=0.01); (6) the traditional criteria for the diagnosis of clinical chorioamnionitis had poor diagnostic performance in identifying proven intra-amniotic infection (overall accuracy, 40-58%); (7) neonatal bacteremia was diagnosed in 4.9% (2/41) of cases; and (8) a fetal inflammatory response defined as the presence of severe acute funisitis was observed in 33% (9/27) of cases.

CONCLUSIONS

Clinical chorioamnionitis at term, a syndrome that can result from intra-amniotic infection, was diagnosed in approximately 63% of cases and sterile intra-amniotic inflammation in 5% of cases. However, a substantial number of patients had no evidence of intra-amniotic infection or intra-amniotic inflammation. Evidence of the fetal inflammatory response syndrome was frequently present, but microorganisms were detected in only 4.9% of cases based on cultures of aerobic and anaerobic bacteria in neonatal blood.

Detection of Volatile Organic Compounds as Potential Novel Biomarkers for Chorioamnionitis - Proof of Experimental Models

Background: Histologic chorioamnionitis is only diagnosed postnatally which prevents interventions. We hypothesized that volatile organic compounds (VOCs) in the amniotic fluid might be useful biomarkers for chorioamnionitis and that VOC profiles differ between amnionitis of different origins. Methods: Time-mated ewes received intra-amniotic injections of media or saline (controls), or live Ureaplasma parvum serovar 3 (Up) 14, 7 or 3d prior to c-section at day 124 gestational age (GA). 100 μg recombinant ovine IL-1α was instilled at 7, 3 or 1d prior to delivery. Headspace VOC profiles were measured from amniotic fluids at birth using ion mobility spectrometer coupled with multi-capillary columns. Results: 127 VOC peaks were identified. 27 VOCs differed between samples from controls and Up- or IL-1α induced amnionitis. The best discrimination between amnionitis by Up vs. IL-1α was reached by 2-methylpentane, with a sensitivity/specificity of 96/95% and a positive predictive value/negative predictive values of 96 and 95%. The concentration of 2-methylpentane in VOCs peaked 7d after intra-amniotic instillation of Up. Discussion: We established a novel method to study headspace VOC profiles of amniotic fluids. VOC profiles may be a useful tool to detect and to assess the duration of amnionitis induced by Up. 2-methylpentane was previously described in the exhalate of women with pre-eclampsia and might be a volatile biomarker for amnionitis. Amniotic fluids analyzed by ion mobility spectrometry coupled with multi-capillary columns may provide bedside diagnosis of amnionitis and understanding inflammatory mechanisms during pregnancy.

Cellular immune responses in amniotic fluid of women with a sonographic short cervix

Objectives A sonographic short cervix is one of the strongest predictors of preterm delivery. However, the cellular immune composition of amniotic fluid in women with a short cervix has not yet been described. Herein, we determined cellular and soluble immune responses in amniotic fluid from pregnant women with a mid-trimester asymptomatic short cervix. Methods Amniotic fluid samples (n=77) were collected from asymptomatic women with a cervical length between 15 and 25 mm (n=36, short cervix) or ≤15 mm (n=41, severely short cervix) diagnosed by ultrasound. Flow cytometry and multiplex measurement of cytokines/chemokines were performed. Results (1) The cellular immune composition of amniotic fluid did not differ between women with a severely short cervix (≤15 mm) and those with a short cervix 15-25 mm; (2) amniotic fluid concentrations of multiple cytokines/chemokines were higher in women with a severely short cervix (≤15 mm) than in those with a short cervix 15-25 mm; (3) the cellular immune composition of amniotic fluid did not differ between women with a severely short cervix (≤15 mm) who ultimately underwent preterm delivery and those who delivered at term; and (4) amniotic fluid concentrations of IL-2, but not other immune mediators, were increased in women with a severely short cervix (≤15 mm) who ultimately delivered preterm compared to those who delivered at term. Conclusions Women with a severely short cervix (≤15 mm) have increased concentrations of pro-inflammatory mediators in the amniotic cavity; yet, these do not translate to changes in the cellular immune response.

The fetal inflammatory response syndrome: the origins of a concept, pathophysiology, diagnosis, and obstetrical implications

The fetus can deploy a local or systemic inflammatory response when exposed to microorganisms or, alternatively, to non-infection-related stimuli (e.g., danger signals or alarmins). The term "Fetal Inflammatory Response Syndrome" (FIRS) was coined to describe a condition characterized by evidence of a systemic inflammatory response, frequently a result of the activation of the innate limb of the immune response. FIRS can be diagnosed by an increased concentration of umbilical cord plasma or serum acute phase reactants such as C-reactive protein or cytokines (e.g., interleukin-6). Pathologic evidence of a systemic fetal inflammatory response indicates the presence of funisitis or chorionic vasculitis. FIRS was first described in patients at risk for intraamniotic infection who presented preterm labor with intact membranes or preterm prelabor rupture of the membranes. However, FIRS can also be observed in patients with sterile intra-amniotic inflammation, alloimmunization (e.g., Rh disease), and active autoimmune disorders. Neonates born with FIRS have a higher rate of complications, such as early-onset neonatal sepsis, intraventricular hemorrhage, periventricular leukomalacia, and death, than those born without FIRS. Survivors are at risk for long-term sequelae that may include bronchopulmonary dysplasia, neurodevelopmental disorders, such as cerebral palsy, retinopathy of prematurity, and sensorineuronal hearing loss. Experimental FIRS can be induced by intra-amniotic administration of bacteria, microbial products (such as endotoxin), or inflammatory cytokines (such as interleukin-1), and animal models have provided important insights about the mechanisms responsible for multiple organ involvement and dysfunction. A systemic fetal inflammatory response is thought to be adaptive, but, on occasion, may become dysregulated whereby a fetal cytokine storm ensues and can lead to multiple organ dysfunction and even fetal death if delivery does not occur ("rescued by birth"). Thus, the onset of preterm labor in this context can be considered to have survival value. The evidence so far suggests that FIRS may compound the effects of immaturity and neonatal inflammation, thus increasing the risk of neonatal complications and long-term morbidity. Modulation of a dysregulated fetal inflammatory response by the administration of antimicrobial agents, anti-inflammatory agents, or cell-based therapy holds promise to reduce infant morbidity and mortality.

Management of pregnancy after fertility-sparing surgery for cervical cancer

Cervical cancer is increasingly diagnosed in women who have not yet completed their reproductive plans. For women with early-stage disease (FIGO stage IA1-IB1), fertility-sparing procedures, such as conization, trachelectomy or radical trachelectomy, represent the treatments of choice. However, women who undergo repeated conization or trachelectomy represent a challenge for obstetricians because they are at increased risk of infertility, mid-trimester miscarriage, preterm premature rupture of membranes and preterm delivery. So far, the evidence-based guidance on the management of these pregnancies is limited. This article reviews the literature discussing pregnancy management in women after fertility-sparing surgery for early cervical cancer. Although the evidence is limited, certain measures are desirable, including screening and treatment of asymptomatic bacteriuria, screening for cervical incompetence and progressive cervical shortening by transvaginal ultrasonography, and fetal fibronectin testing. Vaginal progesterone supplementation should be primary prevention for all women after trachelectomy. Women with a history of preterm delivery or late miscarriage may benefit from cervical cerclage. Elective delivery by cesarean section in the early-term period is desirable.

The Identification of Immune-Related Plasma Proteins Associated with Spontaneous Preterm Delivery and Intra-Amniotic Infection in Women with Premature Cervical Dilation or an Asymptomatic Short Cervix

BACKGROUND

We aimed to investigate whether various immune-related plasma proteins, alone or in combination with conventional clinical risk factors, can predict spontaneous preterm delivery (SPTD) and intra-amniotic infection in women with premature cervical dilation or a short cervix (≤ 25 mm).

METHODS

This retrospective study included 80 asymptomatic women with premature cervical dilation (n = 50) or a short cervix (n = 30), who underwent amniocentesis at 17-29 weeks. Amniotic fluid (AF) was cultured, and maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and complements C3a and C5a, using enzyme-linked immunosorbent assay (ELISA) kits. The primary outcome measures were SPTD at < 32 weeks and positive AF cultures.

RESULTS

The plasma levels of IL-6, C3a, and C5a, but not of MMP-9 and TIMP-1, were significantly higher in women with SPTD at < 32 weeks than in those who delivered at ≥ 32 weeks. The women who delivered at < 32 weeks had more advanced cervical dilatation, and higher rates of antibiotic and tocolytic administration and were less likely to be given vaginal progesterone than those who delivered at ≥ 32 weeks. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma IL-6 and C3a levels, and cervical dilatation (area under the curve [AUC], 0.901). The AUC for this model was significantly greater than that for any single variable included in the predictive model. In the univariate analysis, plasma IL-6 level was the only significant predictor of intra-amniotic infection.

CONCLUSION

In women with premature cervical dilation or a short cervix, maternal plasma IL-6, C3a, and C5a levels could be useful non-invasive predictors of SPTD at < 32 weeks. A combination of these biomarkers and conventional clinical factors may clearly improve the predictability for SPTD, as compared with the biomarkers alone. An increased plasma level of IL-6 predicted intra-amniotic infection.

Cervical epithelial damage promotes Ureaplasma parvum ascending infection, intrauterine inflammation and preterm birth induction in mice

Around 40% of preterm births are attributed to ascending intrauterine infection, and Ureaplasma parvum (UP) is commonly isolated in these cases. Here we present a mouse model of ascending UP infection that resembles human disease, using vaginal inoculation combined with mild cervical injury induced by a common spermicide (Nonoxynol-9, as a surrogate for any mechanism of cervical epithelial damage). We measure bacterial load in a non-invasive manner using a luciferase-expressing UP strain, and post-mortem by qPCR and bacterial titration. Cervical exposure to Nonoxynol-9, 24 h pre-inoculation, facilitates intrauterine UP infection, upregulates pro-inflammatory cytokines, and increases preterm birth rates from 13 to 28%. Our results highlight the crucial role of the cervical epithelium as a barrier against ascending infection. In addition, we expect the mouse model will facilitate further research on the potential links between UP infection and preterm birth.

Evidence that intra-amniotic infections are often the result of an ascending invasion - a molecular microbiological study

Background Microbial invasion of the amniotic cavity resulting in intra-amniotic infection is associated with obstetrical complications such as preterm labor with intact or ruptured membranes, cervical insufficiency, as well as clinical and histological chorioamnionitis. The most widely accepted pathway for intra-amniotic infection is the ascension of microorganisms from the lower genital tract. However, hematogenous dissemination of microorganisms from the oral cavity or intestine, retrograde seeding from the peritoneal cavity through the fallopian tubes, and introduction through invasive medical procedures have also been suggested as potential pathways for intra-amniotic infection. The primary reason that an ascending pathway is viewed as most common is that the microorganisms most often detected in the amniotic fluid are those that are typical inhabitants of the vagina. However, thus far, no studies have shown that microorganisms in the amniotic cavity are simultaneously present in the vagina of the woman from which they were isolated. The objective of the study was to determine the frequency with which microorganisms isolated from women with intra-amniotic infection are also present in the lower genital tract. Methods This was a cross-sectional study of women with intra-amniotic infection with intact membranes. Intra-amniotic infection was defined as a positive culture and elevated concentrations of interleukin-6 (IL-6) (>2.6 ng/mL) in amniotic fluid and/or acute histologic chorioamnionitis and funisitis. Microorganisms isolated from bacterial cultures of amniotic fluid were taxonomically identified through matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) and 16S ribosomal RNA (rRNA) gene sequencing. Vaginal swabs were obtained at the time of amniocentesis for the identification of microorganisms in the lower genital tract. The overall bacterial profiles of amniotic fluids and vaginal swabs were characterized through 16S rRNA gene sequencing. The bacterial profiles of vaginal swabs were interrogated for the presence of bacteria cultured from amniotic fluid and for the presence of prominent (>1% average relative abundance) operational taxonomic units (OTUs) within the overall 16S rRNA gene bacterial profiles of amniotic fluid. Results (1) A total of 75% (6/8) of women had bacteria cultured from their amniotic fluid that are typical residents of the vaginal ecosystem. (2) A total of 62.5% (5/8) of women with bacteria cultured from their amniotic fluid also had these bacteria present in their vagina. (3) The microorganisms cultured from amniotic fluid and also detected in the vagina were Ureaplasma urealyticum, Escherichia coli, and Streptococcus agalactiae. (4) 16S rRNA gene sequencing revealed that the amniotic fluid of women with intra-amniotic infection had bacterial profiles dominated by Sneathia, Ureaplasma, Prevotella, Lactobacillus, Escherichia, Gardnerella, Peptostreptococcus, Peptoniphilus, and Streptococcus, many of which had not been cultured from the amniotic fluid samples. (5) Seventy percent (7/10) of the prominent (>1% average relative abundance) OTUs found in amniotic fluid were also prominent in the vagina. Conclusion The majority of women with intra-amniotic infection had bacteria cultured from their amniotic fluid that were typical vaginal commensals, and these bacteria were detected within the vagina at the time of amniocentesis. Molecular microbiological interrogation of amniotic fluid from women with intra-amniotic infection revealed that the bacterial profiles of amniotic fluid were largely consistent with those of the vagina. These findings indicate that ascension from the lower genital tract is the primary pathway for intra-amniotic infection.

Effect of Antibiotic Treatment of Amniotic Fluid Sludge

BACKGROUND

Amniotic fluid sludge refers to the sonographic presence of echogenic, free-floating aggregates of debris located within the amniotic cavity near the internal cervical os of women with intact membranes. Clinically, it is independently associated with increased obstetric, infectious, and neonatal morbidity, including: short cervix, chorioamnionitis, and an increased risk of preterm birth. It is thought to be infectious in nature and has been described as an intrauterine bacterial biofilm. There is little evidence on the impact of treatment with antibiotics on outcome.

OBJECTIVE

To determine whether outpatient antibiotics administered to women with amniotic fluid sludge would reduce preterm birth risk compared to no antibiotic treatment.

MATERIALS AND METHODS

This was a retrospective cohort study of all patients diagnosed with amniotic fluid sludge by transvaginal sonography between 15 and 25 weeks' gestation in the outpatient ultrasound unit at a single academic center between 2010 and 2017. Patients were segregated according to whether they were treated with oral antibiotics at the time of diagnosis. Women with multiple gestation, fetal anomalies, preterm rupture of membranes prior to initial diagnosis of amniotic fluid sludge, and active preterm labor placenta previa and/or suspected accreta were excluded from analysis. Primary outcome of preterm birth at less than 37 weeks' gestation was compared by univariate and regression analysis to control for potential co-linear and/or confounding variables. Additional outcomes were compared by univariate analysis.

RESULTS

A total of 181 patients were initially identified, and 97 patients met inclusion criteria. Of these patients, 51 were treated with oral antibiotics (46 azithromycin and 5 moxifloxacin), and 46 were not treated. The overall incidence of preterm birth at <37 weeks was 49.4 % (48 of 97) and preterm birth <28 weeks was 22.7% (22 of 97). There was no significant difference in preterm birth, either at <37 weeks (P = .47) or <28 weeks (P = .83) between the treated and untreated women. After adjusting for race, body mass index, tobacco use, cervical length, and preterm birth history, antibiotic treatment did not reduce the risk of preterm birth (adjusted odds ratio, 1.3; confidence interval, 0.77-1.9). No differences were seen in the incidence of preterm premature rupture of membranes (P = .94) or median latency from diagnosis to delivery (P = .47). Birthweight (P = .99), sepsis (P = .53), intraventricular hemorrhage (P = .95), and neonatal intensive care unit (NICU) admission (P = .08) were not affected by antibiotic treatment. Antibiotic treatment did not affect the incidence of either clinical or histologic chorioamnionitis (P = .92 and .14, respectively) or histologic stage 2-3 maternal or fetal inflammation (P = .94 and 0.58, respectively). Sonographic resolution of amniotic fluid sludge on first subsequent scan was seen in 34% of antibiotic-treated women and 43% of untreated women (P = .42). There was no difference in latency from diagnosis to delivery or mean gestational age at delivery according to whether sludge resolved or persisted at the first subsequent scan (P = .14 for each).

CONCLUSION

Antibiotic treatment of amniotic fluid sludge is not associated with a reduction in premature birth. Likewise, antibiotic treatment of amniotic fluid sludge was not associated with improvement in other obstetric, neonatal, or pathologic variables. These findings suggest that the presumed infectious nature of sludge and subsequent adverse outcomes are not treated or improved by administration of azithromycin following midtrimester sonographic diagnosis.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Artificial intelligence and amniotic fluid multiomics: prediction of perinatal outcome in asymptomatic women with short cervix

OBJECTIVE

To evaluate the application of artificial intelligence (AI), i.e. deep learning and other machine-learning techniques, to amniotic fluid (AF) metabolomics and proteomics, alone and in combination with sonographic, clinical and demographic factors, in the prediction of perinatal outcome in asymptomatic pregnant women with short cervical length (CL).

METHODS

AF samples, which had been obtained in the second trimester from asymptomatic women with short CL (< 15 mm) identified on transvaginal ultrasound, were analyzed. CL, funneling and the presence of AF 'sludge' were assessed in all cases close to the time of amniocentesis. A combination of liquid chromatography coupled with mass spectrometry and proton nuclear magnetic resonance spectroscopy-based metabolomics, as well as targeted proteomics analysis, including chemokines, cytokines and growth factors, was performed on the AF samples. To determine the robustness of the markers, we used six different machine-learning techniques, including deep learning, to predict preterm delivery < 34 weeks, latency period prior to delivery < 28 days after amniocentesis and requirement for admission to a neonatal intensive care unit (NICU). Omics biomarkers were evaluated alone and in combination with standard sonographic, clinical and demographic factors to predict outcome. Predictive accuracy was assessed using the area under the receiver-operating characteristics curve (AUC) with 95% CI, sensitivity and specificity.

RESULTS

Of the 32 patients included in the study, complete omics, demographic and clinical data and outcome information were available for 26. Of these, 11 (42.3%) patients delivered ≥ 34 weeks, while 15 (57.7%) delivered < 34 weeks. There was no statistically significant difference in CL between these two groups (mean ± SD, 11.2 ± 4.4 mm vs 8.9 ± 5.3 mm, P = 0.31). Using combined omics, demographic and clinical data, deep learning displayed good to excellent performance, with an AUC (95% CI) of 0.890 (0.810-0.970) for delivery < 34 weeks' gestation, 0.890 (0.790-0.990) for delivery < 28 days post-amniocentesis and 0.792 (0.689-0.894) for NICU admission. These values were higher overall than for the other five machine-learning methods, although each individual machine-learning technique yielded statistically significant prediction of the different perinatal outcomes.

CONCLUSIONS

This is the first study to report use of AI with AF proteomics and metabolomics and ultrasound assessment in pregnancy. Machine learning, particularly deep learning, achieved good to excellent prediction of perinatal outcome in asymptomatic pregnant women with short CL in the second trimester. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Does the human placenta delivered at term have a microbiota? Results of cultivation, quantitative real-time PCR, 16S rRNA gene sequencing, and metagenomics

BACKGROUND

The human placenta has been traditionally viewed as sterile, and microbial invasion of this organ has been associated with adverse pregnancy outcomes. Yet, recent studies that utilized sequencing techniques reported that the human placenta at term contains a unique microbiota. These conclusions are largely based on the results derived from the sequencing of placental samples. However, such an approach carries the risk of capturing background-contaminating DNA (from DNA extraction kits, polymerase chain reaction reagents, and laboratory environments) when low microbial biomass samples are studied.

OBJECTIVE

To determine whether the human placenta delivered at term in patients without labor who undergo cesarean delivery harbors a resident microbiota ("the assemblage of microorganisms present in a defined niche or environment").

STUDY DESIGN

This cross-sectional study included placentas from 29 women who had a cesarean delivery without labor at term. The study also included technical controls to account for potential background-contaminating DNA, inclusive in DNA extraction kits, polymerase chain reaction reagents, and laboratory environments. Bacterial profiles of placental tissues and background technical controls were characterized and compared with the use of bacterial culture, quantitative real-time polymerase chain reaction, 16S ribosomal RNA gene sequencing, and metagenomic surveys.

RESULTS

(1) Twenty-eight of 29 placental tissues had a negative culture for microorganisms. The microorganisms retrieved by culture from the remaining sample were likely contaminants because corresponding 16S ribosomal RNA genes were not detected in the same sample. (2) Quantitative real-time polymerase chain reaction did not indicate greater abundances of bacterial 16S ribosomal RNA genes in placental tissues than in technical controls. Therefore, there was no evidence of the presence of microorganisms above background contamination from reagents in the placentas. (3) 16S ribosomal RNA gene sequencing did not reveal consistent differences in the composition or structure of bacterial profiles between placental samples and background technical controls. (4) Most of the bacterial sequences obtained from metagenomic surveys of placental tissues were from cyanobacteria, aquatic bacteria, or plant pathogens, which are microbes unlikely to populate the human placenta. Coprobacillus, which constituted 30.5% of the bacterial sequences obtained through metagenomic sequencing of placental samples, was not identified in any of the 16S ribosomal RNA gene surveys of these samples. These observations cast doubt as to whether this organism is really present in the placenta of patients at term not in labor.

CONCLUSION

With the use of multiple modes of microbiologic inquiry, a resident microbiota could not be identified in human placentas delivered at term from women without labor. A consistently significant difference in the abundance and/or presence of a microbiota between placental tissue and background technical controls could not be found. All cultures of placental tissue, except 1, did not yield bacteria. Incorporating technical controls for potential sources of background-contaminating DNA for studies of low microbial biomass samples, such as the placenta, is necessary to derive reliable conclusions.

Comparison of two identification and susceptibility test kits for Ureaplasma spp and Mycoplasma hominis in amniotic fluid of patients at high risk for intra-amniotic infection

Objective: Ureaplasma urealyticum and Mycoplasma hominis are the most common microorganisms found in the amniotic fluid of patients at risk for preterm delivery. However, culture techniques for genital mycoplasms require special conditions, are barely considered as part of the evaluation of suspected intra-amniotic infection (IAI) and the results are available within 2 and 7 days. The objectives of this study are to validate the use of two commercially available kits (Mycoplasma IES y MYCOFAST^® RevolutioN) for the identification of Ureaplasma spp. and Mycoplasma hominis in amniotic fluid, to compare the results of these kits with those obtained by culture and real-time polymerase chain reaction (qPCR) and to report the antibiotic sensitivity profile of the genital mycoplasms identified.Methods: This is a prospective cohort study including women with singleton and twin gestations between 16 and 36 weeks. Patients were admitted to perform an amniocentesis due to pregnancy complications considered at high risk for IAI (e.g. preterm labor with intact membranes, preterm prelabour rupture of membranes, short cervix, etc.), treatment of polyhydramnios, and for the assessment of fetal death and fever without a focus.Results: Overall, 93 patients underwent amniocentesis and 63 had results available for all tests. The prevalence of a positive culture was 6% (4/63). There were four cases of Ureaplasma spp. and none of Mycoplasma hominis. The qPCR identified one case as Ureaplasma spp., one case as Ureaplasma parvum and two cases as Ureaplasma urealyticum. For all tests, the diagnostic performance was as follows: sensitivity 100% [95% CI (39.8-100%)], specificity 100% [95% CI (93.9-100%)], positive predictive value 100% [95% CI (39.8-100%)] and negative predictive value 100% [95% CI (93.9-100%)]. In this cohort, Ureaplasma spp. showed low resistance to erythromycin, but a high resistance to clindamycin and clarithromycin that may change according to the antibiotic concentration.Conclusions: To our knowledge, this is the first study that validates the use of the Mycoplasma IES and MYCOFAST^® RevolutioN kits for the identification of genital mycoplasmas in amniotic fluid. The results of these kits are mostly available within 24 hours, have an excellent correlation with those from broth cultures and qPCR and characterize the antibiotic sensitivity profile of the genital mycoplasms identified, providing an opportunity for specific treatment in cases of IAI. Further validation studies in other populations are needed.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Effects of antibiotic therapy in women with the amniotic fluid "sludge" at 15-24 weeks of gestation on pregnancy outcomes

Objective: The aim of this prospective study was to assess the efficacy of antibiotic therapy for the prevention of adverse pregnancy outcomes in women with the amniotic fluid "sludge" at 15-24 weeks of gestation.Methods: 245 women underwent transvaginal ultrasound cervical length measurement at 15-24 weeks of pregnancy and 29 out of them with amniotic fluid "sludge" were included in the study. Eight women with the "sludge" had cervical length >25 mm (Group I), seven-an asymptomatic short cervix (Group IIa) and 14 women with a short cervix had symptoms like low abdominal pain, back pain, and menstrual-like cramps (Group IIb). All participants received intravenous, oral and/or vaginal antibiotic therapy. Participants in Group IIa were additionally given vaginal progesterone (VP), and in Group IIb-VP and indomethacin. Placentas from women with preterm birth (PTB) underwent histological examination.Results: The amniotic fluid "sludge" detected at an ultrasound scan between 15-24 weeks of gestation was associated with long-term maternal infections, histological chorioamnionitis, and was viewed as a marker of intra-amniotic infection. Absence of intravenous antibiotic therapy during midtrimester of pregnancy in these women was associated with neonatal infection with intrauterine onset in 61.1%, postpartum endometritis in 23.1%, and rate of PTB 46.2%. Intravenous antibiotic therapy eliminated sonographic presence of the sludge and resulted in prevented of neonatal and postpartum infections, prevented the risk of PTB in women with the cervical length >25 mm, in those with an asymptomatic short cervix receiving VP, and in 70% of symptomatic women with a short cervix, who received them in combination VP/indomethacin. For those women whose approach was not fully beneficial, it allowed to delay delivery in 11-17 weeks.Conclusions: Although we found that intravenous antibiotic therapy at 15-24 weeks of gestation in women with amniotic fluid "sludge" can protect from infection-related complications and demonstrated high beneficial effects of adding antibiotics to anti-inflammatory drug (indomethacin) and/or VP in women with a short cervix, further larger studies are needed.

Correlation between Ureaplasma spp. sub-group 1 and preterm pre-labour rupture of membranes revealed by an eMLST scheme

Ureaplasma spp. is gaining recognition as an important pathogen associated with preterm birth (PTB) and preterm pre-labour rupture of membranes (PPROM). The aim of this study was to investigate the clonality of this organism in maternal/neonatal pairs with PTB or pre-labour rupture of membranes (PROM) or PPROM and the association between sub-groups and PPROM. In total, 50 of 93 maternal/neonatal pairs that were diagnosed with PTB, PROM or PPROM were identified with Ureaplasma spp. colonized in the amniotic fluid or umbilical cord or placenta. All 104 clinical Ureaplasma spp. samples (50, 30, and 24 cultured from amniotic fluid, umbilical cord, and placenta, respectively) were included for analysis of the genetic lineages using the eMLST scheme. A total of 34 eSTs were revealed, with two predominant eSTs (eST16 and eST41). Interestingly, six maternal/neonatal pairs displayed eST differences in the above three specimen sources. In addition, phylogenetic analysis showed two genetically significant distant clusters, and cluster I included the most clinical strains. Interestingly, there was a significant difference in the prevalence of sub-group 1 of cluster II between women with PPROM and those with PROM. In conclusion, the distribution of cluster I was predominately higher than that of cluster II in maternal/neonatal pairs. In addition, sub-group 1 was prone to associated PPROM through the specific epidemic clonal lineages.

The cytokine network in women with an asymptomatic short cervix and the risk of preterm delivery

PROBLEM

To characterize the amniotic fluid (AF) inflammatory-related protein (IRP) network in patients with a sonographic short cervix (SCx) and to determine its relation to early preterm delivery (ePTD).

METHOD OF STUDY

A retrospective cohort study included women with a SCx (≤25 mm; n=223) who had amniocentesis and were classified according to gestational age (GA) at diagnosis and delivery (ePTD <32 weeks of gestation).

RESULTS

(i) In women with a SCx ≤ 22 1/7 weeks, the concentration of most IRPs increased as the cervix shortened; those with ePTD had a higher rate of increase in MIP-1α, MCP-1, and IL-6 concentrations than those delivering later; and (ii) the concentration of most IRPs and the correlation between several IRP pairs were higher in the ePTD group than for those delivering later.

CONCLUSION

Women with a SCx at 16-22 1/7 weeks have a unique AF cytokine network that correlates with cervical length at diagnosis and GA at delivery. This network may aid in predicting ePTD.

Clinical chorioamnionitis at term VIII: a rapid MMP-8 test for the identification of intra-amniotic inflammation

OBJECTIVE

Clinical chorioamnionitis is the most common infection/inflammatory process diagnosed in labor and delivery units worldwide. The condition is a syndrome that can be caused by (1) intra-amniotic infection, (2) intra-amniotic inflammation without demonstrable microorganisms (i.e. sterile intra-amniotic inflammation), and (3) maternal systemic inflammation that is not associated with intra-amniotic inflammation. The presence of intra-amniotic inflammation is a risk factor for adverse maternal and neonatal outcomes in a broad range of obstetrical syndromes that includes clinical chorioamnionitis at term. Although the diagnosis of intra-amniotic infection has relied on culture results, such information is not immediately available for patient management. Therefore, the diagnosis of intra-amniotic inflammation could be helpful as a proxy for intra-amniotic infection, while results of microbiologic studies are pending. A rapid test is now available for the diagnosis of intra-amniotic inflammation, based on the determination of neutrophil collagenase or matrix metalloproteinase-8 (MMP-8). The objectives of this study were (1) to evaluate the diagnostic indices of a rapid MMP-8 test for the identification of intra-amniotic inflammation/infection in patients with the diagnosis of clinical chorioamnionitis at term, and (2) to compare the diagnostic performance of a rapid MMP-8 test to that of a conventional enzyme-linked immunosorbent assay (ELISA) interleukin (IL)-6 test for patients with clinical chorioamnionitis at term.

MATERIALS AND METHODS

A retrospective cohort study was conducted. A transabdominal amniocentesis was performed in patients with clinical chorioamnionitis at term (n=44). Amniotic fluid was analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital Mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). Amniotic fluid IL-6 concentrations were determined by ELISA, and rapid MMP-8 results were determined by Yoon's MMP-8 Check®. Intra-amniotic inflammation was defined as an elevated amniotic fluid IL-6 concentration ≥2.6 ng/mL, and intra-amniotic infection was diagnosed by the presence of microorganisms in the amniotic fluid accompanied by intra-amniotic inflammation. The diagnostic indices of Yoon's MMP-8 Check® for the identification of intra-amniotic inflammation were calculated. In order to objectively compare Yoon's MMP-8 Check® with the ELISA IL-6 test for the identification of intra-amniotic inflammation, we used an amniotic fluid white blood cell (WBC) count ≥50 cells/mm3 to define intra-amniotic inflammation.

RESULTS

(1) A positive rapid MMP-8 test had a sensitivity of 82.4% (28/34), specificity of 90% (9/10), positive predictive value of 96.6% (28/29), negative predictive value of 60% (9/15), positive likelihood ratio 8.2 (95% CI 1.3-53.2), and negative likelihood ratio 0.2 (95% CI 0.1-0.4) for the identification of intra-amniotic inflammation (prevalence 77.3%); (2) a positive rapid MMP-8 test had a sensitivity of 91.7% (22/24), specificity of 65% (13/20), positive predictive value of 75.9% (22/29), negative predictive value of 86.7% (13/15), positive likelihood ratio of 2.6 (95% CI 1.4-4.8), and negative likelihood ratio of 0.1 (95% CI 0.03-0.5) for the identification of intra-amniotic infection; (3) the rapid MMP-8 test had a significantly higher specificity than the ELISA IL-6 test in the identification of intra-amniotic inflammation as determined by an amniotic fluid WBC count ≥50 cells/mm3. The sensitivity and accuracy of the rapid MMP-8 test were comparable to those of the ELISA IL-6 test; and (4) importantly, the rapid MMP-8 test had 100% sensitivity and 100% negative predictive value in the identification of neonates affected with fetal inflammatory response syndrome (FIRS).

CONCLUSION

The rapid diagnosis of intra-amniotic inflammation is possible by analysis of amniotic fluid using a point-of-care test for MMP-8. Patients with a positive test are at risk of delivering a neonate affected with systemic inflammation, a risk factor for adverse neonatal outcome.

Cervical collagen is reduced in non-pregnant women with a history of cervical insufficiency and a short cervix

INTRODUCTION

Preterm cervical shortening and cervical insufficiency may be caused by a constitutional weakness of the cervix. The aim of this study was to assess the cervical collagen concentration in non-pregnant women with a history of cervical insufficiency or of a short cervix in the second trimester of pregnancy.

MATERIAL AND METHODS

In this case-control study we included non-pregnant women one year or more after pregnancy: 55 controls with a history of normal delivery; 27 women with a history of cervical insufficiency; and 10 women with a history of a short cervix (<5th percentile) and 10 women with a history of a long cervix (>95th percentile) at gestational weeks 18-20. We obtained biopsies (3 × 3-4 mm) from the ectocervix and determined the collagen concentration by measuring the hydroxyproline concentration.

RESULTS

Women with cervical insufficiency had lower collagen concentrations (63.5 ± 5.1%; mean ± SD) compared with controls (68.2 ± 5.4%; p = 0.0004); area under the ROC curve 0.73 (95% CI 0.62-0.84). A cut-off value at 67.6% collagen resulted in a positive likelihood ratio of 3.2, a sensitivity of 60%, and a specificity of 81%. Also, women with a short cervix in the second trimester had lower collagen concentrations in a non-pregnant state (62.1% ± 4.9%) compared with women with a long cervix (67.8% ± 5.0%; p = 0.02).

CONCLUSIONS

Both cervical insufficiency and a short cervix in the second trimester of pregnancy are associated with low cervical collagen concentrations in a non-pregnant state more than one year after pregnancy.

Transabdominal collection of amniotic fluid "sludge" and identification of Candida albicans intra-amniotic infection

A G3P2 patient who conceived while using an intrauterine contraceptive device (IUD) presented at 20 weeks of gestation with mild irregular uterine contractions and vaginal bleeding. Sonographic examination at admission showed the presence of dense amniotic fluid "sludge" and a long sonographic uterine cervix (42 mm). To assess the microbiologic significance of amniotic fluid "sludge", we performed a transabdominal amniocentesis. The procedure was performed under real-time ultrasound, and fluid resembling pus at gross examination was noted. Rapid amniotic fluid analysis showed the presence of a high white blood cell count and structures resembling hyphae. Amniotic fluid cultures were positive for Candida albicans. Treatment was begun with broad-spectrum antibiotics, including Fluconazole, upon the visualization of pus in the "sludge" material because of the presence of hyphae in the Gram stain. Despite treatment, the patient went into spontaneous preterm labor and delivered five days after admission. Placental examination revealed acute fungal histologic chorioamnionitis and funisitis. This represents the first report of transabdominal collection and analysis of amniotic fluid "sludge" and the microbiologic detection of Candida albicans in this material. This report provides evidence that transabdominal retrieval of "sludge" is possible and may be of significant value for patient management and selection of antimicrobial agents.

Short cervical lengths initially detected in mid-trimester and early in the third trimester in asymptomatic twin gestations: Association with histologic chorioamnionitis and preterm birth

Objective

To determine whether short cervical lengths (≤20 mm) that were initially detected in mid-trimester and early in the third trimester are independently associated with increased risks of subsequent histologic chorioamnionitis and spontaneous preterm birth (SPTB, defined as a delivery before 34 weeks) in asymptomatic women with twin pregnancies.

Material and methods

This is a prospective study including 292 consecutive asymptomatic women with twin gestations. Cervical length measurements were carried out at 20 to 24 weeks’ gestation and at 28 to 32 weeks’ gestation. Both placentas of each twin pair were examined histologically after delivery. The generalized estimation equations models and logistic regression analysis were used for statistical analyses.

Results

Multivariable generalized estimation equations analysis revealed that short cervical length at mid-trimester was independently associated with an increased risk for subsequent histologic chorioamnionitis, whereas short cervical length initially detected early in the third trimester was not. By using the likelihood of SPTB as an outcome variable, multivariable logistic regression analysis indicated that short mid-trimester cervical length and histologic chorioamnionitis were independently associated with a greater risk for SPTB. Similarly, based on the multivariable analysis, a short third trimester cervical length was independently and significantly associated with a greater risk for SPTB.

Conclusions

In asymptomatic women with twin pregnancies, a short mid-trimester cervical length is independently associated with an increased risk of both subsequent histologic chorioamnionitis and SPTB, whereas a short cervical length initially detected early in the third trimester is independently associated with preterm delivery, but not subsequent histologic chorioamnionitis.

Insuffisance cervicale et cerclage cervical

OBJECTIF

La présente directive clinique a pour but de fournir un cadre de référence que les cliniciens pourront utiliser pour identifier les femmes qui sont exposées aux plus grands risques de connaître une insuffisance cervicale, ainsi que pour déterminer les circonstances en présence desquelles la mise en place d'un cerclage pourrait s'avérer souhaitable. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed ou MEDLINE, CINAHL et The Cochrane Library en 2012 au moyen d'un vocabulaire contrôlé (p. ex. « uterine cervical incompetence ») et de mots clés appropriés (p. ex. « cervical insufficiency », « cerclage », « Shirodkar », « cerclage », « MacDonald », « cerclage », « abdominal », « cervical length », « mid-trimester pregnancy loss »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en janvier 2011. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales.

VALEURS

La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau). RECOMMANDATIONS.