The prevalence and clinical significance of intraamniotic infection with Candida species in women with preterm labor

Role of Maternal Infections and Inflammatory Responses on Craniofacial Development

Pregnancy is a tightly regulated immunological state. Mild environmental perturbations can affect the developing fetus significantly. Infections can elicit severe immunological cascades in the mother's body as well as the developing fetus. Maternal infections and resulting inflammatory responses can mediate epigenetic changes in the fetal genome, depending on the developmental stage. The craniofacial development begins at the early stages of embryogenesis. In this review, we will discuss the immunology of pregnancy and its responsive mechanisms on maternal infections. Further, we will also discuss the epigenetic effects of pathogens, their metabolites and resulting inflammatory responses on the fetus with a special focus on craniofacial development. Understanding the pathophysiological mechanisms of infections and dysregulated inflammatory responses during prenatal development could provide better insights into the origins of craniofacial birth defects.

Comparative antifungal activity of amniotic fluid against different Candida species

BACKGROUND

Although Candida is a commensal of the urogenital tract, intrauterine fungal infections are extremely uncommon in clinical practice.

AIMS

In the present work we evaluated whether amniotic fluid (AF) possesses direct antifungal activity against clinical isolates of Candidaalbicans and other Candida species.

METHODS

A total of 23 AF samples from pregnant women with gestational age of 38-41 weeks were obtained under aseptic conditions by the aspiration of the amniotic sac during cesarean section. Different Candida species were inoculated in amniotic fluid and Sabouraud broth, used as control, and were incubated at 37°C for 48h. Quantitative cultures of test samples and controls were performed at 0, 4, 8, 12, 24, and 48h.

RESULTS

AF collected from 23 pregnant women had consistent and significant inhibitory activity against all Candida isolates tested. Nonetheless, a complete inhibition of growth by all 23 AF samples tested was observed only against Candida glabrata.

CONCLUSIONS

It is likely that the antifungal activity of the AF against C. albicans, C. glabrata and C. parapsilosis observed in vitro also exists in vivo, contributing to protect against intrauterine fungal infections.

Compartmentalized profiling of amniotic fluid cytokines in women with preterm labor

Objective

Amniotic fluid cytokines have been implicated in the mechanisms of preterm labor and birth. Cytokines can be packaged within or on the surface of extracellular vesicles. The main aim of this study was to test whether the protein abundance internal to and on the surface of extracellular vesicles changes in the presence of sterile intra-amniotic inflammation and proven intra-amniotic infection in women with preterm labor as compared to the women with preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection.

Study design

Women who had an episode of preterm labor and underwent an amniocentesis for the diagnosis of intra-amniotic infection or intra-amniotic inflammation were classified into three groups: 1) preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection, 2) preterm labor with sterile intra-amniotic inflammation, and 3) preterm labor with intra-amniotic infection. The concentrations of 38 proteins were determined on the extracellular vesicle surface, within the vesicles, and in the soluble fraction of amniotic fluid.

Results

1) Intra-amniotic inflammation, regardless of detected microbes, was associated with an increased abundance of amniotic fluid cytokines on the extracellular vesicle surface, within vesicles, and in the soluble fraction. These changes were most prominent in women with proven intra-amniotic infection. 2) Cytokine changes on the surface of extracellular vesicles were correlated with those determined in the soluble fraction; yet the magnitude of the increase was significantly different between these compartments. 3) The performance of prediction models of early preterm delivery based on measurements on the extracellular vesicle surface was equivalent to those based on the soluble fraction.

Conclusions

Differential packaging of amniotic fluid cytokines in extracellular vesicles during preterm labor with sterile intra-amniotic inflammation or proven intra-amniotic infection is reported herein for the first time. The current study provides insights into the biology of the intra-amniotic fluid ad may aid in the development of biomarkers for obstetrical disease.

The diagnostic performance of the beta-glucan assay in the detection of intra-amniotic infection with Candida species

INTRODUCTION

A bioassay based on the detection of beta-glucan, a constituent of the cell wall of fungi, has been successfully used to diagnose fungal infections in a variety of biological fluids but not yet in the amniotic fluid.

OBJECTIVE

To determine the diagnostic performance of a beta-glucan bioassay in the detection of Candida species in the amniotic fluid of women who either did or did not have an intrauterine contraceptive device (IUD) in place during an episode of spontaneous preterm parturition.

METHODS

The study population comprised women who had a singleton pregnancy without congenital or chromosomal abnormalities, who experienced preterm labor or preterm prelabor rupture of the fetal membranes, and who underwent a transabdominal amniocentesis for clinical indications. Samples of amniotic fluid were cultured for aerobic and anaerobic bacteria, genital mycoplasmas, and Candida species, and assayed for beta-glucan, using the (1→3)-beta-d-glucan-specific Limulus amebocyte lysate test (beta-glucan assay) in all cases. Amniotic fluid interleukin (IL)-6 assay results were also available for all cases. The beta-glucan assay takes about 1 hour to run: a concentration >80 pg/mL was considered positive for fungi. Sterile intra-amniotic inflammation of the amniotic cavity was defined by the presence of an amniotic fluid IL-6 concentration ≥2.6 ng/mL and a negative amniotic fluid culture.

RESULTS

(1) One hundred ninety-seven (197) women met the study criteria, of whom 58 (29.4%) had an IUD in place; (2) 20 (10.2%) women had a culture of proven intra-amniotic Candida species-related infection, 19 of whom had a positive beta-glucan assay [sensitivity, 95% (19/20; 95% confidence interval (CI): 75.1-99.9%)]; and (3) the specificity of the beta-glucan assay was 75.1% [133/177; 95% CI: 68.1-99.9%]. It was affected by the presence of nonfungal intra-amniotic infections and an IUD, but not by the presence of sterile intra-amniotic inflammation, and there was a significant interaction between the presence of an IUD and nonfungal intra-amniotic infections (estimated for the interaction effect = 2.1923, p value =.026). The assay's specificity was reduced when nonfungal intra-amniotic infections were diagnosed but only in women who did not have an IUD. Among women without an IUD, the assay's specificity was 91.4% (117/128); it was 93% (106/114) for those without intra-amniotic infection, and 78.6% (11/14) for those with a nonfungal intra-amniotic infection; the difference was not significant (p = .09). Among women with an IUD, the assay's specificity was 32.7% (16/49); 42.9% (9/21) for those with a nonfungal intra-amniotic infection; and 25% (7/28) for those without intra-amniotic infection; and the difference was significant (p = .03).

CONCLUSIONS

The beta-glucan assay is a sensitive, rapid, point-of-care test used to diagnose intra-amniotic Candida species-related infection, and it has a high specificity in pregnant women who did not have an IUD in place.

Candida Chorioamnionitis Leads to Preterm Birth and Adverse Fetal-Neonatal Outcome

Candida chorioamnionitis is rare but can lead to neonatal infection, high mortality, and neurodevelopmental impairment. We aimed to investigate maternal clinical features and perinatal outcomes and discuss future management strategies. We reviewed the medical records of women with Candida chorioamnionitis at our hospital over a 10-year period (n = 9) and previous published case reports and case series. The most prevalent Candida species was C. albicans (71.3% of the all cases). The most prevalent predisposing condition was preterm premature rupture of membranes (31/123, 25.2%), followed by pregnancy with a retained intrauterine contraceptive device (26/123, 21.1%) and pregnancy after in vitro fertilization (25/123, 20.3%). Preterm labor was the most common symptom (52/123, 42.3%), and only 13% of cases involved fever. Of the infants, 27% of the singletons and 23.8% of the twins were born before 22 gestational weeks, while 60% of the singletons and 76.2% of the twins were born at 22-36 weeks. The median birth weight of the babies born after 22 weeks was 1230 g. The mortality rates of the singletons and twins born after 22 weeks of gestation in the year 2000 or later were 28.6% and 52.4%, respectively. Antenatal treatment for Candida chorioamnionitis has not been established.

Prevalence of vulvovaginal candidiasis in pregnancy at three health centers in Burkina Faso

INTRODUCTION

Pregnant women are more susceptible to vaginal colonization and infection by yeast. The role of Candida colonization in the occurrence of preterm birth is well established. The knowledge of local epidemiology and identification of risk factors for preterm birth is important for the prevention and management strategies. The purpose of the study was to determine the prevalence of Candida sp. in vaginal swabs of pregnant women.

METHODS

Pregnant women attending routine antenatal visits in three primary health centres in Bobo-Dioulasso (Burkina Faso) were enrolled into a cross-sectional study carried out from February to April 2015. Vaginal swabs samples were taken from participants after obtaining oral consent. The swabs were inoculated into Sabouraud's glucose agar supplemented with chloramphenicol and incubated at 37°C for 24 to 48hours under aerobic conditions in order to perform fungal culture. The identification of the Candida species was done by culture on HiCrome Candida Differential Agar at 35°C for 48h for production of species-specific colors.

RESULTS

A total of 229 pregnant women were included. The prevalence of vulvovaginal candidiasis (VVC) was 22.71%, (95% CI [17.45-28.69]). Candida albicans accounted for 40.39% and non-Candida albicans species for 59.61% of the isolates, with mainly C. glabrata (32.69%), C. tropicalis (15.38%) and C. krusei (11.54%).

CONCLUSIONS

This study revealed a high prevalence of non-C. albicans species. The syndromic management guidelines for VVC in Burkina Faso will be revised to include a specific protocol for pregnant women.

The maternal plasma proteome changes as a function of gestational age in normal pregnancy: a longitudinal study

OBJECTIVE

Pregnancy is accompanied by dramatic physiological changes in maternal plasma proteins. Characterization of the maternal plasma proteome in normal pregnancy is an essential step for understanding changes to predict pregnancy outcome. The objective of this study was to describe maternal plasma proteins that change in abundance with advancing gestational age and determine biological processes that are perturbed in normal pregnancy.

STUDY DESIGN

A longitudinal study included 43 normal pregnancies that had a term delivery of an infant who was appropriate for gestational age without maternal or neonatal complications. For each pregnancy, 3 to 6 maternal plasma samples (median, 5) were profiled to measure the abundance of 1125 proteins using multiplex assays. Linear mixed-effects models with polynomial splines were used to model protein abundance as a function of gestational age, and the significance of the association was inferred via likelihood ratio tests. Proteins considered to be significantly changed were defined as having the following: (1) >1.5-fold change between 8 and 40 weeks of gestation; and (2) a false discovery rate-adjusted value of P < .1. Gene ontology enrichment analysis was used to identify biological processes overrepresented among the proteins that changed with advancing gestation.

RESULTS

The following results were found: (1) Ten percent (112 of 1125) of the profiled proteins changed in abundance as a function of gestational age; (2) of the 1125 proteins analyzed, glypican-3, sialic acid-binding immunoglobulin-type lectin-6, placental growth factor, C-C motif-28, carbonic anhydrase 6, prolactin, interleukin-1 receptor 4, dual-specificity mitogen-activated protein kinase 4, and pregnancy-associated plasma protein-A had more than a 5-fold change in abundance across gestation (these 9 proteins are known to be involved in a wide range of both physiological and pathological processes, such as growth regulation, embryogenesis, angiogenesis immunoregulation, inflammation etc); and (3) biological processes associated with protein changes in normal pregnancy included defense response, defense response to bacteria, proteolysis, and leukocyte migration (false discovery rate, 10%).

CONCLUSION

The plasma proteome of normal pregnancy demonstrates dramatic changes in both the magnitude of changes and the fraction of the proteins involved. Such information is important to understand the physiology of pregnancy and the development of biomarkers to differentiate normal vs abnormal pregnancy and determine the response to interventions.

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

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

Sterile and microbial-associated intra-amniotic inflammation in preterm prelabor rupture of membranes

OBJECTIVE

The objectives of this study were to: (1) determine the amniotic fluid (AF) microbiology of patients with preterm prelabor rupture of membranes (PROM); and (2) examine the relationship between intra-amniotic inflammation with and without microorganisms (sterile inflammation) and adverse pregnancy outcomes in patients with preterm PROM.

METHODS

AF samples obtained from 59 women with preterm PROM were analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital mycoplasmas) and with broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). AF concentration of interleukin-6 (IL-6) was determined using ELISA. Results of both tests were correlated with AF IL-6 concentrations and the occurrence of adverse obstetrical/perinatal outcomes.

RESULTS

(1) PCR/ESI-MS, AF culture, and the combination of these two tests each identified microorganisms in 36% (21/59), 24% (14/59) and 41% (24/59) of women with preterm PROM, respectively; (2) the most frequent microorganisms found in the amniotic cavity were Sneathia species and Ureaplasma urealyticum; (3) the frequency of microbial-associated and sterile intra-amniotic inflammation was overall similar [ 29% (17/59)]: however, the prevalence of each differed according to the gestational age when PROM occurred; (4) the earlier the gestational age at preterm PROM, the higher the frequency of both microbial-associated and sterile intra-amniotic inflammation; (5) the intensity of the intra-amniotic inflammatory response against microorganisms is stronger when preterm PROM occurs early in pregnancy; and (6) the frequency of acute placental inflammation (histologic chorioamnionitis and/or funisitis) was significantly higher in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [93.3% (14/15) versus 38% (6/16); p = 0.001].

CONCLUSIONS

(1) The frequency of microorganisms in preterm PROM is 40% using both cultivation techniques and PCR/ESI-MS; (2) PCR/ESI-MS identified microorganisms in the AF of 50% more women with preterm PROM than AF culture; and (3) sterile intra-amniotic inflammation was present in 29% of these patients, and it was as or more common than microbial-associated intra-amniotic inflammation among those presenting after, but not before, 24 weeks of gestation.

Fluconazole treatment of intrauterine Candida albicans infection in fetal sheep

BACKGROUND

Intrauterine Candida albicans infection causes severe fetal inflammatory responses and fetal injury in an ovine model. We hypothesized that intra-amniotic antifungal therapy with fluconazole would decrease the adverse fetal effects of intra-amniotic C. albicans in sheep.

METHODS

Sheep received an intra-amniotic injection of 10(7) colony-forming units C. albicans. After 2 d, animals were then randomized to: (i) intra-amniotic and fetal intraperitoneal saline with delivery after 24 h (3 d C. albicans group); (ii) intra-amniotic and fetal intraperitoneal injections of fluconazole with delivery after either 24 h (3 d C. albicans plus 1 d fluconazole group) or 72 h (5 d C. albicans plus 3 d fluconazole group). Controls received intra-amniotic injections of saline followed by intra-amniotic and fetal intraperitoneal fluconazole injections.

RESULTS

Intra-amniotic C. albicans caused severe fetal inflammatory responses characterized by decreases in lymphocytes and platelets, an increase in posterior mediastinal lymph node weight and proinflammatory mRNA responses in the fetal lung, liver, and spleen. Fluconazole treatment temporarily decreased the pulmonary and chorioamnion inflammatory responses.

CONCLUSION

The severe fetal inflammatory responses caused by intra-amniotic C. albicans infection were transiently decreased with fluconazole. A timely fetal delivery of antimicrobial agents may prevent fetal injury associated with intrauterine infection.

Amniocentesis for threatened preterm labor with intact membranes and the impact on adverse outcome in infants born at 22 to 28 weeks of gestation

BACKGROUND

It remains unclear whether performing amniocentesis to detect intra-amniotic infection is useful for improving neonatal outcomes.

AIMS

To determine the efficacy of amniocentesis on the neonatal outcomes in women exhibiting threatened preterm labor and intact membranes.

STUDY DESIGN

Retrospective cohort study

SUBJECTS

A total of 174 women with threatened preterm labor and intact membranes at 22 to 33 weeks of gestation. Women with obvious clinical chorioamnionitis, multifetal pregnancy and/or major anomalies were excluded.

OUTCOME MEASURES

Neonatal short- and long-term outcomes

RESULTS

Sixty-seven women underwent amniocentesis (Tap group), while the remaining 107 did not. The prevalence of a positive Gram stain or a positive culture result was 10% in the Tap group. The overall outcomes were not statistically different between the two groups, with the exception of borderline significance (p=0.052) in long-term outcomes, favoring the Tap group. We performed a subgroup analysis focusing on infants born at 22-28 weeks of gestation. Consequently, the Tap group had better neonatal outcomes than the no-Tap group with respect to both short-term (OR 0.19, 95%CI 0.07-0.55) and long-term (OR 0.15, 0.05-0.46) outcomes. A multivariate analysis revealed that after adjusting confounding factors, the gestational age at delivery (OR 0.4, 0.3-0.7) and amniocentesis (OR 0.1, 0.02-0.3) remained significantly different.

CONCLUSIONS

Amniocentesis is useful for improving neonatal outcomes in infants born at 22-28 weeks of gestation to women exhibiting preterm labor and intact membranes.

Exploring preterm birth as a polymicrobial disease: an overview of the uterine microbiome

Infection is a leading cause of preterm birth (PTB). A focus of many studies over the past decade has been to characterize microorganisms present in the uterine cavity and document any association with negative pregnancy outcome. A range of techniques have been used to achieve this, including microbiological culture and targeted polymerase chain reaction assays, and more recently, microbiome-level analyses involving either conserved, phylogenetically informative genes such as the bacterial 16S rRNA gene or whole shotgun metagenomic sequencing. These studies have contributed vast amounts of data toward characterization of the uterine microbiome, specifically that present in the amniotic fluid, fetal membranes, and placenta. However, an overwhelming emphasis has been placed on the bacterial microbiome, with far less data produced on the viral and fungal/yeast microbiomes. With numerous studies now referring to PTB as a polymicrobial condition, there is the need to investigate the role of viruses and fungi/yeasts in more detail and in particular, look for associations between colonization with these microorganisms and bacteria in the same samples. Although the major pathway by which microorganisms are believed to colonize the uterine cavity is vertical ascension from the vagina, numerous studies are now emerging suggesting hematogenous transfer of oral microbiota to the uterine cavity. Evidence of this has been produced in mouse models and although DNA-based evidence in humans appears convincing in some aspects, use of methodologies that only detect viable cells as opposed to lysed cells and extracellular DNA are needed to clarify this. Such techniques as RNA analyses and viability polymerase chain reaction are likely to play key roles in the clinical translation of future microbiome-based data, particularly in confined environments such as the uterus, as detection of viable cells plays a key role in diagnosis and treatment of infection.

Intra-amniotic fluconazole therapy for Candida albicans intra-amniotic infection

BACKGROUND

The consequences of intra-amniotic Candida infection can be devastating. Currently, standard management includes delivery. We identified only one previous case reporting intrauterine antifungal therapy, which used transcervical amphotericin B. We present two cases of intra-amniotic Candida infection treated with intra-amniotic fluconazole instilled before membrane rupture.

CASES

Two patients presented with intra-amniotic Candida albicans infection that was diagnosed during previability. Both underwent cerclage placement before culture results were available. Aggressive antifungal therapy was instituted using oral, vaginal, and intra-amniotic fluconazole instilled through serial amniocenteses. Both fetuses survived without sequelae.

CONCLUSION

Intra-amniotic Candida infection is associated with preterm rupture of membranes, preterm labor, severe neonatal infection, and fetal death. Early diagnosis and treatment is essential.

Diversity of microbes in amniotic fluid

Recent polymerase chain reaction (PCR)-based studies estimate the prevalence of microbial invasion of the amniotic cavity (MIAC) to be ≥30-50% higher than that detected by cultivation-based methods. Some species that have been long implicated in causing MIAC remain among the common invaders (e.g. Ureaplasma spp., Mycoplasma spp., Fusobacterium spp. Streptococcus spp., Bacteroides spp. and Prevotella spp.). Yet we now know from studies based on PCR of the 16S ribosomal DNA that cultivation-resistant anaerobes belonging to the family Fusobacteriaceae (particularly Sneathia sanguinegens, and Leptotrichia spp.) are also commonly found in amniotic fluid. Other diverse microbes detected by PCR of amniotic fluid include as-yet uncultivated and uncharacterized species. The presence of some microbial taxa is associated with specific host factors (e.g. Candida spp. and an indwelling intrauterine device). It appears that MIAC is polymicrobial in 24-67% of cases, but the potential role of pathogen synergy is poorly understood. A causal relationship between diverse microbes, as detected by PCR, and preterm birth is supported by types of association (e.g. space, time and dose) proposed as alternatives to Koch's postulates for inferring causality from molecular findings. The microbial census of the amniotic cavity remains unfinished. A more complete understanding may inform future research directions leading to improved strategies for preventing, diagnosing and treating MIAC.

Vaginal Inflammatory Status in Pregnant Women with Normal and Pathogenic Microbiota in Lower Genital Tract

Objective. To assess the vaginal inflammatory status (VIS) in pregnant women, whether symptomatic or asymptomatic, by leukocyte quantification in relation to the microbiota during each pregnancy trimester (T). Materials and Methods. A thousand two hundred and forty eight vaginal exudates from pregnant women were prospectively examined. All the patients underwent a clinical and colposcopic examination and a microbiological study of vaginal exudates. Leukocyte quantification was determined by May-Grunwald Giemsa staining as LNR per field (400X). Results. Statistically significant differences (SSD) in LNR were observed in the VIS of asymptomatic patients (AP) compared with that of symptomatic ones (SP) with normal microbiota: 10–15 for the 1st T, <10, 20 to 25 and >25 for the 2nd T and >25 for the 3rd; with candidiasis: <10 for the 1st T, <10, 15 to 20 and >25 for the 2nd T and <10 and >25 for the 3rd T. In women with trichomoniasis, SSD in the LNR were observed between SP with LNR ≥ 10 and AP with NLR < 10 in the three trimesters altogether. In women with BV, no SSD were observed in the LNR of any AP with respect to SP for the three T. Conclusion. The VIS is influenced by vaginal microbiota and depends on the state of pregnancy and also, on gestational age. The pronounced leukocyte increase in asymptomatic patients in the absence of lower genital tract infection during the third trimester of pregnancy should be highlighted.

Protocol for a randomised controlled trial of treatment of asymptomatic candidiasis for the prevention of preterm birth [ACTRN12610000607077]

Background

Prevention of preterm birth remains one of the most important challenges in maternity care. We propose a randomised trial with: a simple Candida testing protocol that can be easily incorporated into usual antenatal care; a simple, well accepted, treatment intervention; and assessment of outcomes from validated, routinely-collected, computerised databases.

Methods/Design

Using a prospective, randomised, open-label, blinded-endpoint (PROBE) study design, we aim to evaluate whether treating women with asymptomatic vaginal candidiasis early in pregnancy is effective in preventing spontaneous preterm birth. Pregnant women presenting for antenatal care <20 weeks gestation with singleton pregnancies are eligible for inclusion. The intervention is a 6-day course of clotrimazole vaginal pessaries (100 mg) and the primary outcome is spontaneous preterm birth <37 weeks gestation.

The study protocol draws on the usual antenatal care schedule, has been pilot-tested and the intervention involves only a minor modification of current practice. Women who agree to participate will self-collect a vaginal swab and those who are culture positive for Candida will be randomised (central, telephone) to open-label treatment or usual care (screening result is not revealed, no treatment, routine antenatal care). Outcomes will be obtained from population databases.

A sample size of 3,208 women with Candida colonisation (1,604 per arm) is required to detect a 40% reduction in the spontaneous preterm birth rate among women with asymptomatic candidiasis from 5.0% in the control group to 3.0% in women treated with clotrimazole (significance 0.05, power 0.8). Analyses will be by intention to treat.

Discussion

For our hypothesis, a placebo-controlled trial had major disadvantages: a placebo arm would not represent current clinical practice; knowledge of vaginal colonisation with Candida may change participants' behaviour; and a placebo with an alcohol preservative may have an independent affect on vaginal flora. These disadvantages can be overcome by the PROBE study design.

This trial will provide definitive evidence on whether screening for and treating asymptomatic candidiasis in pregnancy significantly reduces the rate of spontaneous preterm birth. If it can be demonstrated that treating asymptomatic candidiasis reduces preterm births this will change current practice and would directly impact the management of every pregnant woman.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12610000607077

Treatment of asymptomatic vaginal candidiasis in pregnancy to prevent preterm birth: an open-label pilot randomized controlled trial

Background

Although the connection between ascending infection and preterm birth is undisputed, research focused on finding effective treatments has been disappointing. However evidence that eradication of Candida in pregnancy may reduce the risk of preterm birth is emerging. We conducted a pilot study to assess the feasibility of conducting a large randomized controlled trial to determine whether treatment of asymptomatic candidiasis in early pregnancy reduces the incidence of preterm birth.

Methods

We used a prospective, randomized, open-label, blinded-endpoint (PROBE) study design. Pregnant women presenting at <20 weeks gestation with singleton pregnancies self-collected a vaginal swab. Those who were asymptomatic and culture positive for Candida were randomized to 6-days of clotrimazole vaginal pessaries (100mg) or usual care (screening result is not revealed, no treatment). The primary outcomes were the rate of asymptomatic vaginal candidiasis, participation and follow-up. The proposed primary trial outcome of spontaneous preterm birth <37 weeks gestation was also assessed.

Results

Of 779 women approached, 500 (64%) participated in candidiasis screening, and 98 (19.6%) had asymptomatic vaginal candidiasis and were randomized to clotrimazole or usual care. Women were not inconvenienced by participation in the study, laboratory testing and medication dispensing were problem-free, and the follow-up rate was 99%. There was a tendency towards a reduction in spontaneous preterm birth among women with asymptomatic candidiasis who were treated with clotrimazole RR = 0.33, 95%CI 0.04-3.03.

Conclusions

A large, adequately powered, randomized trial of clotrimazole to prevent preterm birth in women with asymptomatic candidiasis is both feasible and warranted.

Trial registration

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609001052224

The prognosis of pregnancy conceived despite the presence of an intrauterine device (IUD)

OBJECTIVE

Intrauterine devices (IUDs) are used for contraception worldwide; however, the management of pregnancies with an IUD poses a clinical challenge. The purpose of this study was to determine the outcome of pregnancy in patients with an IUD.

STUDY DESIGN

A retrospective cohort study (December 1997-June 2007) was conducted. The cohort consisted of 12,297 pregnancies, of which 196 had an IUD. Only singleton pregnancies were included. Logistic regression analysis was used to adjust for potential confounders between the groups.

RESULTS

1) Pregnancies with an IUD were associated with a higher rate of late miscarriage, preterm delivery, vaginal bleeding, clinical chorioamnionitis, and placental abruption than those without an IUD; 2) among patients with available histologic examination of the placenta, the rate of histologic chorioamnionitis and/or funisitis was higher in patients with an IUD than in those without an IUD (54.2% vs. 14.7%; P<0.001). Similarly, among patients who underwent an amniocentesis, the prevalence of microbial invasion of the amniotic cavity (MIAC) was also higher in pregnant women with an IUD than in those without an IUD (45.9% vs. 8.8%; P<0.001); and 3) intra-amniotic infection caused by Candida species was more frequently present in pregnancies with an IUD than in those without an IUD (31.1% vs. 6.3%; P<0.001).

CONCLUSION

Pregnant women with an IUD are at a very high risk for adverse pregnancy outcomes. This finding can be attributed, at least in part, to the high prevalence of intra-amniotic infection and placental inflammatory lesions observed in pregnancies with an IUD.

Vaginal and oral microbes, host genotype and preterm birth

Preterm birth (PTB) is a leading cause of infant mortality and morbidity in the US and across the globe. Infection and associated inflammation are important initiators for PTB pathways; an estimated 40% of PTBs are attributed to amniochorionic-decidual or systemic inflammation. Historically, intrauterine infections have been implicated in PTB; recent evidence suggests that infections remote from the fetal site may also be causative. There is strong epidemiological evidence that bacterial vaginosis and periodontitis--two syndromes characterized by perturbations in the normal vaginal and oral bacterial microflora, respectively--are linked to infection-associated PTB. Oral and vaginal environments are similar in their bacterial microbiology; identical bacterial species have been independently isolated in periodontitis and bacterial vaginosis. Periodontitis and bacterial vaginosis also share many behavioral and sociodemographic risk factors suggesting a possible common pathophysiology. Genetic polymorphisms in host inflammatory responses to infection are shared between bacterial vaginosis, periodontitis and PTB, suggesting common mechanisms through which host genotype modify the effect of abnormal bacterial colonization on preterm birth. We review the state of knowledge regarding the risk of PTB attributable to perturbations in bacterial flora in oral and vaginal sites and the role of host genetics in modifying the risk of infection-related PTB. We posit that bacterial species that are common in perturbed vaginal and oral sites are associated with PTB through their interaction with the host immune system.

Crystal structure of FadA adhesin from Fusobacterium nucleatum reveals a novel oligomerization motif, the leucine chain

Many bacterial appendages have filamentous structures, often composed of repeating monomers assembled in a head-to-tail manner. The mechanisms of such linkages vary. We report here a novel protein oligomerization motif identified in the FadA adhesin from the Gram-negative bacterium Fusobacterium nucleatum. The 2.0 angstroms crystal structure of the secreted form of FadA (mFadA) reveals two antiparallel alpha-helices connected by an intervening 8-residue hairpin loop. Leucine-leucine contacts play a prominent dual intra- and intermolecular role in the structure and function of FadA. First, they comprise the main association between the two helical arms of the monomer; second, they mediate the head-to-tail association of monomers to form the elongated polymers. This leucine-mediated filamentous assembly of FadA molecules constitutes a novel structural motif termed the "leucine chain." The essential role of these residues in FadA is corroborated by mutagenesis of selected leucine residues, which leads to the abrogation of oligomerization, filament formation, and binding to host cells.

Diagnostic value of the papanicolaou smear in lower genital tract infections during pregnancy

OBJECTIVES

To evaluate the diagnostic value of the Pap smear in lower genital tract infections during pregnancy.

MATERIALS AND METHODS

A total of 190 pregnant women were examined in the Lower Genital Tract and Colposcopy clinics of the Obstetrics Division at the University Hospital de Clínicas "José de San Martín" of University of Buenos Aires from April to August 1997. Samples were taken from the vaginal fornix for microbiologic study and from the exocervix for Pap smear. Both the sensitivity and specificity test of the Pap smear for diagnosing lower genital tract infections were calculated considering the microbiologic study as the reference standard.

RESULTS

The sensitivity of the Pap smear for Candida spp., bacterial vaginosis and Trichomonas vaginalis compared with microbiologic study was 50, 81, and 78, respectively. The specificity for the same study was 96%, 93%, and 100%, respectively.

CONCLUSIONS

Pap smear for diagnosing lower genital tract infections is useful when positive results are found for these infections because of its high specificity.

Pathophysiology, diagnosis, and management of intraamniotic infection

Intraamniotic infection (IAI) is a term used to describe a clinically diagnosed infection of the contents of the uterus. It is found most often after rupture of the membranes. The most useful diagnostic tests are physical examination, amniotic fluid glucose determination, and amniotic fluid Gram's stain. There is no clearly established means for the prevention of IAI, but cervical examinations and cervical manipulation can increase the risk, so caution with their use is still warranted. Treatment for this infection should be initiated when the diagnosis is made to provide the lowest risk of neonatal and maternal complications. Ampicillin or penicillin plus gentamicin are the most extensively tested antibiotics for treatment before delivery. Clindamycin or metronidazole should be added if a cesarean section is performed. As a general rule, antibiotics should be continued postpartum until the patient has been afebrile and asymptomatic for a minimum of 24 hours. Neonatal complications of IAI may be substantial especially for the premature fetus. Women with this infection have a greater risk for dysfunctional labor and cesarean section.

Fetal Candida infection associated with an intrauterine contraceptive device

Fetal Candida infection is rarely described but is often associated with a retained intrauterine contraceptive device (IUCD). A case of abortion due to Candida infection in a patient wearing an IUCD is reported.

Fluconazole in Candida albicans sepsis during pregnancy: case report and review of the literature

Candida sepsis during pregnancy is a rare but life-threatening complication of infection with Candida albicans. In contrast to the situation with other antimicrobial agents, there exists only limited experience with systemic antifungal therapy during pregnancy. A recent report focuses on amphotericin B treatment in systemic fungal infection during pregnancy. The present report discusses a pregnant patient with Candida albicans sepsis and endophthalmitis as well as candida infection of the oral and genital mucous membranes, after hyperalimentation and broad spectrum antibiotic therapy via a central venous catheter. The patient was treated with 10 mg/kg fluconazole from week 16 of gestation for a total duration of 50 days. Adverse effects did not occur and the rest of the pregnancy proceeded favourably for both the mother and the baby.

Pregnancy with an intrauterine device in situ and preterm delivery

We determined the prevalence of preterm delivery in a population of women who conceived with an IUD in situ and compared the results with those in a group of women without any contraceptive method. The study group consisted of 16 women who conceived with a copper IUD in situ. The control group comprised 48 women matched for age, gravidity and parity. The prevalence of preterm delivery was significantly higher in the study group than in the control group (18.7% (3/16) vs 2% (1/48)), respectively. (P = 0.045, Fisher's exact test.)