***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE : The reported incidence of acute pelvic inflammatory disease ( PID ) has decreased but rates of tubal infertility have not , suggesting that a large proportion of PID leading to infertility may be undetected . Sub clinical PID is common in women with uncomplicated chlamydial or gonococcal cervicitis or with bacterial vaginosis . We assessed whether women with sub clinical PID are at an increased risk for infertility . METHODS : A prospect i ve observational cohort of 418 women with or at risk for gonorrhea or chlamydia or with bacterial vaginosis was recruited . Women with acute PID were excluded . An endometrial biopsy was performed to identify endometritis ( sub clinical PID ) . After provision of therapy for gonorrhea , chlamydia and bacterial vaginosis participants were followed-up for fertility outcomes . RESULTS : There were 146 incident pregnancies during follow-up , 50 pregnancies in 120 ( 42 % ) women with sub clinical PID and 96 in 187 ( 51 % ) women without sub clinical PID . Women with sub clinical PID diagnosed at enrollment had a 40 % reduced incidence of pregnancy compared with women without sub clinical PID ( hazard ratio 0.6 , 95 % confidence interval 0.4–0.8 ) . Women with Neisseria gonorrhoeae or Chlamydia trachomatis , in the absence of sub clinical PID , were not at increased risk for infertility . CONCLUSION : Sub clinical PID decreases subsequent fertility despite provision of treatment for sexually transmitted diseases . These findings suggest that a proportion of female infertility is attributable to sub clinical PID and indicate that current therapies for sexually transmitted diseases are inadequate for prevention of infertility . LEVEL OF EVIDENCE : Objective : The aim of this study was investigate the impact of vaginal flora and vaginal inflammation on conception and early pregnancy loss following  in-vitro fertilization ( IVF ) . Methods : We enrolled 91 women who were undergoing IVF .  At embryo transfer  ( ET ) , all of the women had quantitative vaginal culture , ET catheter-tip culture , and vaginal Gram stain scored for bacterial vaginosis and quantitated for polymorphonuclear leukocytes ( PMNs ) . Conception and early pregnancy loss were compared with culture and Gram stain results . Statistical analyses included the Chi-square test , Fisher 's exact test and the Mann – Whitney U-test . Results : The overall live birth rate ( LBR ) was 30 % ( 27/91 ) , and the rate of early pregnancy loss was 34 % ( 14/41 ) . In women with bacterial vaginosis , intermediate flora and normal flora , the conception rates were 30 % ( 3/10 ) , 39 % ( 12/31 ) and 52 % ( 26/50 ) , respectively ( p = 0.06 for trend ) . Early pregnancy loss occurred in 33 % ( 1/3 ) , 42 % ( 5/12 ) and 31 % ( 8/26 ) of women , respectively ( p = 0.06 , comparing intermediate and normal flora ) . The vaginal log concentration of hydrogen peroxide-producing lactobacilli was 7.3 ± 1.7 in women with a live birth ( n = 27 ) and 4.9 ± 2.5 in those with early pregnancy loss ( n = 14 ) ( p = 0.1 ) . Conclusions : IVF patients with bacterial vaginosis and with a decreased vaginal log concentration of hydrogen peroxide-producing lactobacilli may have decreased conception rates and increased rates of early pregnancy loss . A larger prospect i ve treatment trial design ed to evaluate the impact on IVF outcomes of optimizing the vaginal flora prior to IVF may be warranted Objectives : To vali date a simplified grading scheme for Gram stained smears of vaginal fluid for the diagnosis of bacterial vaginosis ( BV ) against the accepted “ gold ” st and ard of Amsel ’s composite criteria . Methods : Women attending genitourinary medicine ( GUM ) clinics , as part of a multicentre study , were diagnosed as having BV if three or more of the following criteria were present ; homogeneous discharge , elevated vaginal pH , production of amines , and presence of “ clue ” cells . Women with less than three of the criteria were considered as normal . Simultaneously , smears were made of vaginal fluid and Gram stained and then assessed qualitatively as normal ( grade I ) , intermediate ( grade II ) , or consistent with BV ( grade III ) . Two new grade s were used , grade 0 , epithelial cells only with no bacteria , and grade IV , Gram positive cocci only . Results : BV was diagnosed in 83/162 patient visits using the composite criteria , the remainder being regarded as normal . The majority of patients with BV had a smear assessed as grade III ( 80/83 , 96 % ) and the majority of normal women had a smear assessed as grade I ( normal , 48/79 , 61 % ) , giving a high sensitivity ( 97.5 % ) , specificity ( 96 % ) , and predictive value for a positive ( 94.1 % ) and negative ( 96 % ) test , kappa index = 0.91 . Smears assessed as grade II were found predominantly ( 12/13 ) among patients diagnosed as normal , with less than three of the composite criteria . Grade s 0 and IV were both only found among normal women . Conclusion : This simplified assessment of Gram stained smears can be used as an alternative to Amsel ’s criteria and is more applicable for use in busy GUM clinics Objective To assess whether the rate of bacterial vaginosis ( BV ) is higher in women with tubal factor infertility compared with those with other causes of infertility Purpose The aim of this study was to investigate the impact of bacterial vaginal flora on life-birth rate  during ICSI and influence of metronidazole as antibiotic treatment course before ICSI . Method We enrolled 71 women who were undergoing ICSI .  At embryo transfer ( ET ) , all of the women had quantitative vaginal culture , ET catheter-tip culture , and vaginal Gram stain scored for bacterial vaginosis . Results The overall live birth rate ( LBR ) was 36.6 % ( 26/71 ) , and the rate of early pregnancy loss was 13 % ( 4/30 ) . In women with bacterial vaginosis , intermediate flora and normal flora , the conception rates were 35 % ( 9/26 ) , 42 % ( 14/33 ) and 58 % ( 7/12 ) , respectively ( p = 0.06 for trend ) .  Metronidazole  effect to bacterial flora in vaginal . The predominant species isolated from the tip of the embryo transfer catheter in negative pregnancy was Staphylococcus epidermidis ( 7 vs. 15.2 % ) , and Streptococcus viridians ( 11 vs. 24 % ) . Conclusions Woman with bacterial vaginosis and with a decreased vaginal concentration of hydrogen peroxide-producing lactobacilli may have decreased conception rates and increased rates of failed pregnancy . A larger prospect i ve treatment trial design ed to evaluate the impact on ICSI outcomes of optimizing the vaginal flora prior to ICSI may be warranted The objective of this prospect i ve cohort study was to eluci date whether bacterial vaginosis ( BV ) is associated with a pro-inflammatory endometrial secretion cytokine profile and whether there is a relationship between BV and the concentrations of a number of key regulatory cytokines , chemokines and growth factors . A total of 198 women undergoing IVF treatment were included . Prior to embryo transfer , participants underwent screening for BV according to Nugent criteria by a Gram-stained cervical smear . The concentrations of 17 soluble mediators of human implantation were measured by multiplex immunoassay in endometrial secretions aspirated prior to embryo transfer . Seventeen ( 8.6 % ) women had BV ( Nugent score > 6 ) . Multivariable logistic regression showed a significant positive association between interleukin-beta and the presence of BV ( P=0.011 ; Nugent score > 6 versus 6 ) and a significant negative association between eotaxin and BV ( P=0.003 ) . No significant differences were found in the ratios of distinct pro- and anti-inflammatory cytokines in endometrial secretions from women with or without BV . In conclusion , BV is associated with higher concentrations of interleukin-beta in endometrial secretions compared with women without BV . However , no distinct difference in pro- and anti-inflammatory profiles is present . An effect on endometrial receptivity is unlikely 
    Output:
    
SUMMARY ANSWER The incidence of BV is significantly higher among patients with tubal infertility when compared with patients with non-tubal infertility .
BV does not impinge on conception rates but is significantly associated with pre clinical pregnancy loss , though not with first trimester abortion .
Still , there is strong circumstantial evidence that supports a causal link between BV and tubal infertility .
Studies with a longitudinal design , on the other h and , strongly support a relation between BV and early pregnancy loss .
Unfortunately , no study looked beyond first trimester fetal loss , although it is plausible that the high preterm birth rates with IVF are , at least , in part attributable to BV