First Trimester Levels of BV-Associated Bacteria and Risk of Miscarriage Among Women Early in Pregnancy

A prospective cohort study examining the association between the periconceptual vaginal microbiota and first-trimester miscarriage in Kenyan women

BACKGROUND

Studies evaluating the association between the vaginal microbiota and miscarriage have produced variable results.

OBJECTIVE

This study evaluated the association between periconceptual and first-trimester vaginal microbiota and women's risk for miscarriage.

METHODS

At monthly preconception visits and at 9-12 weeks gestation, women collected vaginal swabs for molecular characterisation of the vaginal microbiota. Participants who became pregnant were followed to identify miscarriage versus pregnancy continuing to at least 20 weeks gestation.

RESULTS

Forty-five women experienced miscarriage and 144 had pregnancies continuing to ≥20 weeks. A principal component analysis of periconceptual and first-trimester vaginal bacteria identified by 16S rRNA gene PCR with next-generation sequencing did not identify distinct bacterial communities with miscarriage versus continuing pregnancy. Using taxon-directed quantitative PCR assays, increasing concentrations of Megasphaera hutchinsoni, Mageeibacillus indolicus, Mobiluncus mulieris and Sneathia sanguinegens/vaginalis were not associated with miscarriage. In exploratory analyses, these data were examined as a binary exposure to allow for multivariable modelling. Detection of Mobiluncus mulieris in first-trimester samples was associated with miscarriage (adjusted relative risk [aRR] 2.14, 95% confidence interval [CI] 1.08, 4.22). Additional analyses compared women with early first-trimester miscarriage (range 4.7-7.3 weeks) to women with continuing pregnancies. Mobiluncus mulieris was detected in all eight (100%) first-trimester samples from women with early first-trimester miscarriage compared to 101/192 (52.6%) samples from women with continuing pregnancy (model did not converge). Detection of Mageeibacillus indolicus in first-trimester samples was also associated with early first-trimester miscarriage (aRR 4.10, 95% CI 1.17, 14.31).

CONCLUSIONS

The primary analyses in this study demonstrated no association between periconceptual or first-trimester vaginal microbiota and miscarriage. Exploratory analyses showing strong associations between first-trimester detection of Mobiluncus mulieris and Mageeibacillus indolicus and early first-trimester miscarriage suggest the need for future studies to determine if these findings are reproducible.

Microorganism-derived extracellular vesicles: emerging contributors to female reproductive health

Extracellular vesicles (EVs) are cell-derived nanoparticles that carry small molecules, nucleic acids, and proteins long distances in the body facilitating cell-cell communication. Microorganism-derived EVs mediate communication between parent cells and host cells, with recent evidence supporting their role in biofilm formation, horizontal gene transfer, and suppression of the host immune system. As lipid-bound bacterial byproducts, EVs demonstrate improved cellular uptake and distribution in vivo compared to cell-free nucleic acids, proteins, or small molecules, allowing these biological nanoparticles to recapitulate the effects of parent cells and contribute to a range of human health outcomes. Here, we focus on how EVs derived from vaginal microorganisms contribute to gynecologic and obstetric outcomes. As the composition of the vaginal microbiome significantly impacts women's health, we discuss bacterial EVs from both healthy and dysbiotic vaginal microbiota. We also examine recent work done to evaluate the role of EVs from common vaginal bacterial, fungal, and parasitic pathogens in pathogenesis of female reproductive tract disease. We highlight evidence for the role of EVs in women's health, gaps in current knowledge, and opportunities for future work. Finally, we discuss how leveraging the innate interactions between microorganisms and mammalian cells may establish EVs as a novel therapeutic modality for gynecologic and obstetric indications.

Culturomics reveals a hidden world of vaginal microbiota with the isolation of 206 bacteria from a single vaginal sample

The composition of the vaginal microbiota is known to be influenced by various factors and to be associated with several disorders affecting women's health. Although metagenomics is currently a widely used method for studying the human microbiota, it has certain limitations, such as a lack of information on bacterial viability. It is therefore important to use culture-based methods such as culturomics. Here, we used 35 different culture conditions to comprehensively characterize the vaginal bacterial diversity of a single woman's flora. A total of 206 bacterial species, belonging to six phyla (for a little more than half to Firmicutes, followed mainly by Actinobacteria, Bacteroidetes, and Proteobacteria) and 45 families, and 2 fungal species were cultivated. While several species of lactobacilli have been isolated, a wide variety of other bacteria were also separated, including 65 never reported before in vaginal flora, including a new bacterial species, Porphyromonas vaginalis sp. nov. Extensive culture-based methods are essential to establish a comprehensive, evidence-based repertoire of bacterial viability. If combined with molecular methods, they can provide a much more thorough understanding of the vaginal microbiota and fulfil the unknown part of metagenomic studies.

Role of the vaginal microbiome in miscarriage: exploring the relationship

Miscarriage is a devastating pregnancy loss that affects many women worldwide. It is characterized as a spontaneous miscarriage that occurs before 20 weeks of gestation which affects more than 25% of pregnancies. While the causes of miscarriage are complex and multifactorial, recent research has suggested a potential role of the vaginal microbiota. The vaginal microbiome is a dynamic ecosystem of microbes that are essential for preserving vaginal health and avoiding infections. Vaginal dysbiosis has been accompanied with numerous adverse pregnancy complications, such as preterm birth. However, the effect of the vaginal microbiome in miscarriage is not fully understood. This review aims to investigate the link between vaginal microbiota and miscarriage. Also, we investigate the various mechanisms through which the vaginal microbiota may affect miscarriage. Additionally, we examine the implications of these research findings, specifically the possibility of vaginal microbiome screening and targeted interventions to prevent miscarriage.

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.

In vitro and ex vivo models for evaluating vaginal drug delivery systems

Vaginal drug delivery systems are often preferred for treating a variety of diseases and conditions of the female reproductive tract (FRT), as delivery can be more targeted with less systemic side effects. However, there are many anatomical and biological barriers to effective treatment via the vaginal route. Further, biocompatibility with the local tissue and microbial microenvironment is desired. A variety of in vitro and ex vivo models are described herein for evaluating the physicochemical properties and toxicity profile of vaginal drug delivery systems. Deciding whether to utilize organoids in vitro or fresh human cervicovaginal mucus ex vivo requires careful consideration of the intended use and the formulation characteristics. Optimally, in vitro and ex vivo experimentation will inform or predict in vivo performance, and examples are given that describe utilization of a range of methods from in vitro to in vivo. Lastly, we highlight more advanced model systems for other mucosa as inspiration for the future in model development for the FRT.

Miscarriage Risk Factors for Pregnant Women: A Cohort Study in Eastern Algeria’s Population

Background

Miscarriage is defined as an adverse and unexpected termination of pregnancy; it is the most frequent pregnancy complication. Here, we aimed to identify the factors predisposing to miscarriage in pregnant women in Eastern Algeria and the effect of the combination of several factors, including maternal Body Mass Index (BMI), maternal age, concomitant pathologies, and nutrients, and to predict the occurrence of miscarriage.

Methods

A total of 786 pregnant women from Eastern Algeria were interviewed between 2011 and 2015. Association between miscarriage exposure and identified risk factors was assessed using a Generalized Linear Model (GLM), ANOVA test, Multiple Correspondence Analysis (MCA), and Hierarchical Clustering Analysis (HCA). Throughout this study, we sought to find answers, discuss this association, and predict the occurrence of miscarriage.

Results

We developed a predictive model for miscarriage, and we found that miscarriage was significantly higher for pregnant women aged over 35 years (1.75; 95% CI: 0.75-4.37; p = 0.208), with a high BMI (> 25 kg/m²), (1.88; 95% CI:1.28-2.78; p = 0.001). We have highlighted that miscarriage is strongly associated with hypertension (1.67; 95% CI: 1.16-2.39; p = 0.006), diet rich in meat (0.60; 95% CI: 0.33-1.04; p = 0.075), and moderate in fish (2.32; 95% CI: 1.18-4.58; p = 0.015).

Conclusion

Our study proved that knowing these risk factors helps to establish predictive models and strategies to prevent tragic pregnancy outcomes and highlights the link between miscarriage and several risk factors; and thus, will allow protecting mother and fetus health.

Bacterial Vaginosis and Prospective Ultrasound Measures of Uterine Fibroid Incidence and Growth

BACKGROUND

Uterine fibroids often cause intolerable symptoms leading to invasive treatments, most commonly hysterectomy. Reproductive tract infections are hypothesized to influence uterine fibroid development, but few studies exist, especially for the highly prevalent condition bacterial vaginosis (BV). Both fibroids and BV have documented racial-ethnic disparities, with higher burden in Blacks.

METHODS

With prospective data from a community-based study (four standardized ultrasound examinations over 5 years) in young Black women, we examined baseline BV associations with fibroid incidence and growth. We computed adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incidence comparing BV and no BV (Nugent score ≥7 vs. <7) using Cox proportional hazards models among 1027 women fibroid-free at baseline. Fibroid growth associations were based on linear mixed models estimating volume change between ultrasounds indexed to 18 months. We then expressed BV association as estimated percent difference in growth per 18 months, comparing exposed and unexposed.

RESULTS

There were n = 247 incident fibroids and 1181 growth measures; average fibroid growth per 18 months was a 78% (95% CI: 69 to 87) increase in volume. BV prevalence was 51% and not associated with fibroid incidence (aHR: 1.0, 95% CI: 0.80 to 1.4) or growth (estimated % difference in growth, -3% (95% CI: -12 to 6).

CONCLUSIONS

In this first study (to our knowledge) of ultrasound-monitored fibroid development and Nugent-assessed BV, we found no evidence to support the hypothesis that BV increased risk of fibroid incidence or growth or BV's role in the high burden of fibroids in Black women.

Bacterial Vaginosis: What Do We Currently Know?

The vaginal microbiome is a well-defined compartment of the human microbiome. It has unique conditions, characterized by the dominance of one bacterial species, the Lactobacilli. This microbiota manifests itself by a low degree of diversity and by a strong dynamic of change in its composition under the influence of various exogenous and endogenous factors. The increase in diversity may paradoxically be associated with dysbiosis, such as bacterial vaginosis (BV). BV is the result of a disturbance in the vaginal ecosystem; i.e., a sudden replacement of Lactobacilli by anaerobic bacteria such as Gardnerella vaginalis, Atopobium vaginae, Ureaplasma urealyticum, Mycoplasma hominis, and others. It is the most common cause of vaginal discharge in women of childbearing age, approximately 30% of all causes. The etiology of this dysbiosis remains unknown, but its health consequences are significant, including obstetrical complications, increased risk of sexually transmitted infections and urogenital infections. Its diagnosis is based on Amsel’s clinical criteria and/or a gram stain based on the Nugent score. While both of these methods have been widely applied worldwide for approximately three decades, Nugent score are still considered the “gold standard” of BV diagnostic tools. Given the limitations of these tools, methods based on molecular biology have been developed as alternative rational strategies for the diagnosis of BV. The treatment of BV aims at restoring the balance of the vaginal flora to stop the proliferation of harmful microorganisms. Prescription of antibiotics such as metronidazole, clindamycin, etc. is recommended. Faced with the considerable uncertainty about the cause of BV, the high rate of recurrence, the unacceptable treatment options, and clinical management which is often insensitive and inconsistent, research on this topic is intensifying. Knowledge of its composition and its associated variations represents the key element in improving the therapeutic management of patients with the most suitable treatments possible.

Can Lactobacillus spp. Be a Factor Reducing the Risk of Miscarriage?

Pregnancy loss is a common obstetric problem. Significant causes of miscarriage include genetic and epigenetic disorders of the embryo, immunological and endocrine factors, uterine malformations, improper embryo selection, and lifestyle. Perhaps a hitherto underappreciated cause of miscarriage may be an abnormal microbiota composition of the female reproductive system. Lactobacillus spp. is the most common bacteria within the reproductive tract. However, the protective role of Lactobacilli in the vagina has been well described in the literature, while it is still unknown what function Lactobacilli may have in the uterus. Moreover, new research shows that Lactobacillus spp. can have a role in miscarriage. However, both molecular and immunological mechanisms of host-Lactobacillus spp. interactions are not fully understood. Understanding these relationships will help address the importance and extent of the protective role of Lactobacillus spp. in miscarriage.

The relationship between genitourinary microorganisms and oxidative stress, sperm DNA fragmentation and semen parameters in infertile men

An imbalance in the genitourinary microbiome is emerging as a contributing factor to male infertility. The purpose of this study was to determine whether there is an association between genitourinary microorganisms and seminal oxidative stress, sperm DNA fragmentation and semen parameters. It included 770 men attending for diagnostic testing for subfertility. Genitourinary microorganisms were identified in 43.0% men; 20.1% had microorganisms in semen; 18.7% in urine; and 5.8% had microorganisms in urine and semen. Enterococcus faecalis was the most prevalent organism in semen (22.0% samples; 61.5% organisms) with Ureaplasma spp. (16.9% samples; 53.3% organisms) and Gardnerella vaginalis (11.4% samples; 37.4% organisms) most prevalent in urine. Semen parameters were unaffected by microorganisms (p > 0.05). Seminal ROS were significantly higher in men with microorganisms compared to those without (p < 0.001), particularly when present in both urine and semen (p < 0.01). Microorganisms were associated with significantly higher DNA fragmentation, irrespective of whether they were in semen or urine (p < 0.001). An imbalance in the genitourinary microbiome is associated with DNA damage and oxidative stress which may have considerable consequences for achieving an ongoing pregnancy. This highlights the need for incorporating genitourinary microorganism screening for all men as part of diagnostic evaluation prior to undergoing treatment for infertility.

Is there an association between the vaginal microbiome and first trimester miscarriage? A prospective observational study

AIM

To examine whether there are differences in the vaginal microbiome of women who miscarry compared to those who have normal pregnancy outcomes.

METHODS

Prospective observational study conducted at the Canberra Hospital, Australia, with 24 participant women in the first trimester of pregnancy. The vaginal microbiomes of the 24 women were characterized using sequencing analysis of the V4 region of the 16S rRNA gene employing an Illumina MiSeq instrument with QIAGEN reagents. Vaginal microbiome data were correlated with pregnancy clinical metadata.

RESULTS

Ordination plots showed differences in the composition of microbiomes of women who miscarried and controls. In nulliparous women, Lactobacillus crispatus was the dominant bacterium in 50% of women. Lactobacillus iners was the dominant bacterium in 50% of women with a history of prior miscarriage and a miscarriage in the study compared to 15% (p = 0.011) in those with no history of miscarriage and no miscarriage in the study. There were significant differences in the number of operational taxonomic units and the richness of the microbiomes of women who miscarried compared to those who delivered at term. Eight taxa were found in different relative abundances in both groups of women.

CONCLUSIONS

The study indicated that the composition of the vaginal microbiome varies with pregnancy history. Also, there was a significant difference in the vaginal microbiomes between women who suffered miscarriage and those who continued to term delivery both in the overall microbiome populations and in the abundances of individual taxa.

Bacterial Vaginosis-Associated Bacteria and Uterine Fibroids: A Nested Case-Control Study

BACKGROUND

Reproductive tract infections are hypothesized to influence uterine fibroid development, yet few studies have investigated the common condition of bacterial vaginosis (BV). The literature is currently limited to data using self-report of BV.

METHODS

We conducted a nested case-control study of 200 women (100 cases and 100 controls) from a large study of 23- to 35-year-old African American women, 1310 of whom were fibroid-free and prospectively followed up for 5 years to identify incident fibroids with standardized ultrasound examinations. We used quantitative polymerase chain reaction, an objective molecular method, to assess 9 BV-associated and 4 Lactobacillus species from vaginal swab specimens. We used hierarchical logistic regression to compute odds ratios and 95% confidence intervals to examine associations between bacterial species (both individually and grouped as (1) "optimal" Lactobacillus and (2) BV-associated species) with fibroid incidence and number. We also examined vaginal imbalance (quantitatively more BV-associated bacteria than optimal Lactobacilli).

RESULTS

Contrary to our hypothesis, we found no increase in fibroid incidence or number among women with more BV-associated bacteria. High imbalance (only BV-associated bacteria, no optimal Lactobacillus bacteria) was actually inversely associated with fibroid incidence (odds ratio, 0.38; 95% confidence interval, 0.17-0.81).

CONCLUSIONS

This is the first study of ultrasound-detected incident fibroids and molecular vaginal bacterial assessment. We found no evidence that BV-associated bacteria increase the risk of fibroid incidence or number.

Exploration of the Vaginal and Gut Microbiome in African American Women by Body Mass Index, Class of Obesity, and Gestational Weight Gain: A Pilot Study

OBJECTIVE

This study determines the differences in the distal gut and vaginal microbiome in African American (AA) women by prepregnancy body mass index and gestational weight gain (GWG) comparing women with and without obesity and by obesity class.

STUDY DESIGN

We prospectively sampled the vaginal and distal gut microbiome in pregnant AA women at two time points during pregnancy. Samples were analyzed using high-throughput sequencing of the V4 region of the 16S ribosomal ribonucleic acid gene.

RESULTS

Distinct differences in vaginal and distal gut α-diversity were observed at time point 1 between women with and without obesity by total GWG. Significant differences in distal gut β-diversity were also found at time point 1 in obese women by GWG. Within the Bacteroides genus, a significant association was observed by total GWG among obese women which was absent in nonobese women. Women with class III obesity who experienced low GWG had the lowest abundance of distal gut Bacteroides and appreciably higher relative abundance of a consortia of vaginal taxa including Atopobium, Gardnerella, Prevotella, and Sneathia.

CONCLUSION

These results contribute new evidence showing that GWG in combination with obesity and obesity class is associated with an altered distal gut and vaginal composition early in pregnancy among AA women.

Vaginal probiotic adherence and acceptability in Rwandan women with high sexual risk participating in a pilot randomised controlled trial: a mixed-methods approach

OBJECTIVES

To evaluate adherence and acceptability of intermittent vaginal probiotic or antibiotic use to prevent bacterial vaginosis (BV) recurrence.

DESIGN

Repeated adherence and acceptability assessments using mixed methods within a pilot randomised controlled trial.

SETTING

Research clinic in Kigali, Rwanda.

PARTICIPANTS

Rwandan women with high sexual risk.

INTERVENTIONS

Women diagnosed with BV and/or trichomoniasis were randomised to four groups (n=17 each) after completing metronidazole treatment: behavioural counselling only, or behavioural counselling plus 2-month intermittent use of oral metronidazole, Ecologic Femi+ (EF+) vaginal capsule or Gynophilus LP (GynLP) vaginal tablet.

OUTCOME MEASURES

Adherence and acceptability were assessed by structured face-to-face interviews, semi-structured focus group discussions and in-depth interviews, daily diaries and counting of used/unused study products in randomised women (n=68). Vaginal infection knowledge was assessed by structured face-to-face interviews in randomised women and women attending recruitment sessions (n=131).

RESULTS

Most women (93%) were sex workers, 99.2% were unfamiliar with BV and none had ever used probiotics. All probiotic users (n=32) reported that insertion became easier over time. Triangulated adherence data showed that 17/17 EF+ users and 13/16 GynLP users used ≥80% of required doses (Fisher's exact p=0.103). Younger age (p=0.076), asking many questions at enrolment (p=0.116), having menses (p=0.104) and reporting urogenital symptoms (p=0.103) were non-significantly associated with lower perfect adherence. Women believed that the probiotics reduced BV recurrence, but reported that partners were sometimes unsupportive of study participation. Self-reported vaginal washing practices decreased during follow-up, but sexual risk behaviours did not. Most women (12/15) with an uncircumcised steady partner discussed penile hygiene with him, but many women found this difficult, especially with male clients.

CONCLUSIONS

High-risk women require education about vaginal infections. Vaginal probiotic acceptability and adherence were high in this cohort. Our results can be used to inform future product development and to fine-tune counselling messages in prevention programmes.

TRIAL REGISTRATION NUMBER

NCT02459665.

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-State Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species—particularly Lactobacillus crispatus—are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis—including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.

The cervicovaginal mucus barrier to HIV-1 is diminished in bacterial vaginosis

Bacterial vaginosis (BV), a condition in which the vaginal microbiota consists of community of obligate and facultative anaerobes rather than dominated by a single species of Lactobacillus, affects ~30% of women in the US. Women with BV are at 60% increased risk for HIV acquisition and are 3-times more likely to transmit HIV to an uninfected partner. As cervicovaginal mucus (CVM) is the first line of defense against mucosal pathogens and the home of the resident vaginal microbiota, we hypothesized the barrier function of CVM to HIV may be diminished in BV. Here, we characterized CVM properties including pH, lactic acid content, and Nugent score to correlate with the microbiota community composition, which was confirmed by 16S rDNA sequencing on a subset of samples. We then quantified the mobility of fluorescently-labeled HIV virions and nanoparticles to characterize the structural and adhesive barrier properties of CVM. Our analyses included women with Nugent scores categorized as intermediate (4–6) and BV (7–10), women that were either symptomatic or asymptomatic, and a small group of women before and after antibiotic treatment for symptomatic BV. Overall, we found that HIV virions had significantly increased mobility in CVM from women with BV compared to CVM from women with Lactobacillus crispatus-dominant microbiota, regardless of whether symptoms were present. We confirmed using nanoparticles and scanning electron microscopy that the impaired barrier function was due to reduced adhesive barrier properties without an obvious degradation of the physical CVM pore structure. We further confirmed a similar increase in HIV mobility in CVM from women with Lactobacillus iners-dominant microbiota, the species most associated with transitions to BV and that persists after antibiotic treatment for BV. Our findings advance the understanding of the protective role of mucus and highlight the interplay between vaginal microbiota and the innate barrier function mucus.

Bacterial vaginosis (BV), a condition characterized by the depletion of lactobacillus bacteria in the vagina, is the most common vaginal condition in reproductive age women. BV has been associated with many adverse reproductive and sexual health outcomes, including increased risk of HIV infection. Cervicovaginal mucus is the home to vaginal bacteria and acts as a first line of defense to protect the underlying tissues and cells from infection. Here, we studied the barrier properties of mucus from women with BV compared to women with vaginal bacteria dominated by lactobacilli. We found that mucus from women with BV and women with Lactobacillus iners were permissive to HIV-1, which may allow the virus to more easily reach target cells. These findings are in agreement with the observed increased risk for HIV acquisition seen in women with BV and L. iners bacteria. Furthermore, we found that the barrier against HIV is diminished in women with BV regardless of whether they have symptoms. Our findings highlight the important, yet unexplored interactions between the mucus barrier and the vaginal microbiota and the implications for human health.

Association between vaginal washing and vaginal bacterial concentrations

Vaginal washing is a common practice associated with adverse outcomes including bacterial vaginosis (BV) and HIV infection. Prior studies have not examined the associations between vaginal washing and individual vaginal bacteria, or whether these associations are independent of the effect of vaginal washing on BV. The purpose of this study was to characterize the association between vaginal washing and the presence and concentrations of vaginal bacteria associated with optimal and sub-optimal vaginal states. The analysis utilized data from participants in the placebo arm of the Preventing Vaginal Infections trial, which enrolled HIV-uninfected women from the United States and Kenya. Detection of bacterial taxa associated with BV was compared between visits with versus without reported vaginal washing. The effect of vaginal washing on a number of vaginal bacteria differed substantially (p<0.05) between the US and Kenya, so results were stratified by country. In US women, vaginal washing was associated with a significantly higher likelihood of detection of BV associated bacterium 1 (BVAB1) (relative risk [RR] 1.55, 95% confidence interval [CI] 1.15-2.09, p = 0.004), BVAB2 (RR 1.99, 95%CI 1.46-2.71, p<0.001), Mageeibacillus indolicus (RR 2.08, 95%CI 1.46-2.96, p<0.001), Atopobium vaginae (RR 1.34, 95%CI 1.13-1.59, p = 0.001), Leptotrichia/Sneathia species (RR 1.66, 95% CI 1.33-2.09, p<0.001), Megasphaera species (RR 1.78, 95%CI 1.34-2.37, p<0.001) and Gardnerella vaginalis (RR 1.08, 95%CI 1.01-1.16, p = 0.02). No significant association between vaginal washing and bacterial detection was found in Kenyan women. Adjustment for bacterial vaginosis diagnosed by Gram stain did not alter these results. This study provides evidence that the association between vaginal washing and detection of individual bacterial taxa can vary regionally. For some vaginal bacteria, the association with vaginal washing may be independent of the effect on Gram stain detection of BV. Larger prospective studies in diverse geographic settings should explore whether eliminating vaginal washing impacts the presence and concentrations of key vaginal bacteria.

Polymorphisms and haplotypes in VDR gene are associated with female idiopathic infertility

Unexplained infertility refers to the absence of a definable cause of reproductive failure. Vitamin D receptor (VDR) acts as a transcription factor and regulates a number of vitamin D-responsive genes, including those involved in the immune system. Recent finding that VDR is expressed in reproductive tissues suggests a possible importance of vitamin D in pregnancy. We conducted a case-control study to examine the association of polymorphisms in VDR gene with reproductive success. DNA from 117 female patients with unexplained infertility and 130 fertile controls was isolated from peripheral blood and VDR genotypes (FokI, BsmI, ApaI and TaqI) were detected by PCR-RFLP. Haplotypes were determined using Haploview software. Our results show significant association of FokI and BsmI polymorphisms with infertility (p < 0.05). The haplotype analysis confirmed strong linkage disequilibrium between closely positioned BsmI, ApaI and TaqI polymorphisms. Two haplotypes were associated with infertility: (i) haplotype bAT was increasing the risk for secondary infertility; while (ii) haplotype BAT had a protective role against primary infertility (p < 0.05). By changing the expression and the activity of VDR gene, which leads to the change in expression of vitamin D-responsive genes, these polymorphisms and haplotypes could possibly have an effect on immune system in the female reproductive tract.

Serum 25-Hydroxyvitamin D and Risk of Self-Reported Bacterial Vaginosis in a Prospective Cohort Study of Young African American Women

BACKGROUND

Bacterial vaginosis (BV), the leading cause of vaginal discharge, is associated with multiple adverse health outcomes; however, its etiology is unknown. BV treatment is not very effective, thus prevention approaches are needed. Studies investigating the impact of vitamin D on the risk of BV have had mixed findings, including two studies reporting increased risk of recurrent BV for women with higher vitamin D.

MATERIALS AND METHODS

Participants were nonpregnant women in a prospective fibroid study of African Americans (ages 23-34 years) from the Detroit area. The exposure was seasonally adjusted annual mean serum 25-hydroxyvitamin D [25(OH)D] at enrollment. The outcome was self-reported doctor-diagnosed BV over ∼20 months between baseline and follow-up. Multivariable-adjusted binomial regression models estimated the risk of BV for a doubling of 25(OH)D and sufficient (≥20 ng/mL) versus deficient (<20 ng/mL) 25(OH)D.

RESULTS

In total, 1459 women were included. Median 25(OH)D was 15.2 ng/mL and 73% were deficient. Sixteen percent of participants reported BV diagnoses over follow-up, 78% of whom had recurrent BV. In multivariable-adjusted analyses, a doubling of 25(OH)D was associated with an increased, rather than the hypothesized decreased, risk of self-reported BV (risk ratio [RR] 1.22, 95% confidence interval 1.02-1.48). Sufficient women also had a significantly higher, rather than lower, risk of self-reported BV (RR 1.31). Results were robust to sensitivity analyses, and post hoc analyses showed no evidence of reverse causation.

CONCLUSIONS

Overall, our findings do not support vitamin D deficiency as a risk factor for BV in these young, nonpregnant African American women.

Prevalence of bacterial vaginosis in Portuguese pregnant women and vaginal colonization by Gardnerella vaginalis

Background

We aimed to determine the prevalence of vaginal colonization by Gardnerella vaginalis and of bacterial vaginosis (BV) in Portuguese pregnant women, and to identify risk factors for BV and G. vaginalis colonization in pregnancy.

Methods

A cross-sectional study was conducted among pregnant women aged ≥ 18 years who were attending in two public hospitals of the Northwest region of Portugal. Epidemiological data was collected by anonymous questionnaire. BV was diagnosed by Nugent criteria and G. vaginalis presence was identified by polymerase chain reaction. Crude associations between the study variables and BV or G. vaginalis colonization were quantified by odds ratios (ORs) and their 95% confidence intervals (CIs).

Results

The prevalences of BV and of G. vaginalis colonization among Portuguese pregnant women were 3.88% and 67.48%, respectively. Previous preterm delivery and colonization by G. vaginalis were factors with very high OR, but only statistically significant for a 90% CI. Conversely, higher rates of G. vaginalis colonization were found in women with basic educational level (OR = 2.77, 95% CI [1.33–5.78]), during the second trimester of pregnancy (OR = 6.12, 95% CI [1.80–20.85]) and with BV flora (OR = 8.73, 95% CI [0.50–153.60]).

Discussion

Despite the lower number of women with BV, prevalence ratios and association with risk factors were similar to recent European studies. However, the percentage of healthy women colonized by G. vaginalis was significantly higher than many previous studies, confirming that G. vaginalis colonization does not always lead to BV development.

Bacterial vaginosis and the risk of early miscarriage in women undergoing intracytoplasmic sperm injection cycles: a prospective cohort study

This study aimed to assess the possible association of bacterial vaginosis (BV) and early miscarriage in 408 women undergoing intracytoplasmic sperm injection (ICSI) for reasons of male infertility. A vaginal sample was obtained before oocyte retrieval and evaluated for BV-associated bacteria using the Nugent scoring system. The primary outcome was early miscarriage and the secondary outcomes included implantation, pregnancy, late miscarriage, preterm delivery and live birth rates. Chi-square, ANOVA, relative risk and odds ratio were used for data analysis where appropriate. The prevalence of BV was estimated as 7.3%. From 336 patients who had embryo transfer, 138 patients (41.1%) conceived. A total of 17% (n = 23) of pregnant women miscarried during the first trimester: 15 patients (15%) were normal, 4 (17.4%) were intermediate and 4 (26.7%) patients had BV (p = 0.52). The relative risk of early miscarriage in BV patients compared to the non-BV and intermediate group was 1.77 (0.68-4.64, 95% CI). Implantation, pregnancy, preterm delivery and live birth rates were comparable between groups. We conclude that BV does not appear to have an adverse impact on outcomes in women being treated with ICSI for male factor infertility and is not associated with miscarriage and preterm birth.

Vaginal Microbiome and Its Relationship to Behavior, Sexual Health, and Sexually Transmitted Diseases

The vaginal microbiota has great significance in maintaining vaginal health and protecting the host from disease. Recent advances in molecular techniques and informatics allow researchers to explore microbial composition in detail and to compare the structure of vaginal microbial communities with behavior and health outcomes, particularly acquisition and transmission of sexually transmitted diseases (STDs) and poor birth outcomes. Vaginal flora have been found to cluster into a limited number of communities, although community structure is dynamic. Certain community types are more associated with poor reproductive outcomes and STDs; communities dominated by Lactobacillus species, particularly Lactobacillus crispatus, are most associated with vaginal health. Modifiable and nonmodifiable factors are strongly associated with community composition, including behavior, race or ethnicity, and hygiene. In this review, we describe the state of the science on the vaginal microbiome and its relationship to behavior, sexual health, and STDs, including determinants of the microbiome that go beyond an individual level.

Impact of Periodic Presumptive Treatment for Bacterial Vaginosis on the Vaginal Microbiome among Women Participating in the Preventing Vaginal Infections Trial

Background

Evidence suggests that specific vaginal bacteria associated with bacterial vaginosis (BV) may increase the risk of adverse health outcomes in women. Among women participating in a randomized, double-blinded trial, we assessed the effect of periodic presumptive treatment (PPT) on detection of select vaginal bacteria.

Methods

High-risk women from the United States and Kenya with a recent vaginal infection received intravaginal metronidazole 750 mg plus miconazole 200 mg or placebo for 5 consecutive nights each month for 12 months. Vaginal fluid specimens were collected via polyester/polyethylene terephthalate swabs every other month and tested for bacteria, using quantitative polymerase chain reaction (PCR) assays targeting the 16S ribosomal RNA gene. The effect of PPT on bacterium detection was assessed among all participants and stratified by country.

Results

Of 234 women enrolled, 221 had specimens available for analysis. The proportion of follow-up visits with detectable quantities was lower in the PPT arm versus the placebo arm for the following bacteria: BVAB1, BVAB2, Atopobium vaginae, Leptotrichia/Sneathia, and Megasphaera. The magnitude of reductions was greater among Kenyan participants as compared to US participants.

Conclusions

Use of monthly PPT for 1 year reduced colonization with several bacteria strongly associated with BV. The role of PPT to improve vaginal health should be considered, and efforts to improve the impact of PPT regimens are warranted.

[Bacterial vaginosis and spontaneous preterm birth]

OBJECTIVE

To determine if bacterial vaginosis is a marker for risk of spontaneous preterm delivery and if its detection and treatment can reduce this risk.

METHODS

Consultation of the database Pubmed/Medline, Science Direct, and international guidelines of medical societies.

RESULTS

Bacterial vaginosis (BV) is a dysbiosis resulting in an imbalance in the vaginal flora through the multiplication of anaerobic bacteria and jointly of a disappearance of well-known protective Lactobacilli. His diagnosis is based on clinical Amsel criteria and/or a Gram stain with establishment of the Nugent score. The prevalence of the BV extraordinarily varies according to ethnic and/or geographical origin (4-58 %), in France, it is close to 7 % in the first trimester of pregnancy (EL2). The link between BV and spontaneous premature delivery is low with an odds ratio between 1.5 and 2 in the most recent studies (EL3). Metronidazole or clindamycin is effective to treat BV (EL3). It is recommended to prescribe one of these antibiotics in the case of symptomatic BV (Professional Consensus). The testing associated with the treatment of BV in the global population showed no benefit in the prevention of the risk of spontaneous preterm delivery (EL2). Concerning low-risk asymptomatic population (defined by the absence of antecedent of premature delivery), it has been failed profit to track and treat the BV in the prevention of the risk of spontaneous preterm delivery (EL1). Concerning the high-risk population (defined by a history of preterm delivery), it has been failed profit to track and treat the VB in the prevention of the risk of spontaneous preterm delivery (EL3). However, in the sub population of patients with a history of preterm delivery occurred in a context of materno-fetal bacterial infection, there may be a benefit to detect and treat early and systematically genital infection, and in particular the BV (Professional Consensus).

CONCLUSION

The screening and treatment of BV during pregnancy in asymptomatic low-risk population is not recommended in the prevention of the risk of spontaneous preterm delivery (grade A). In the population at high risk with the only notion of antecedent of premature delivery, screening and treatment of the BV is not recommended (grade C).