***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: OBJECTIVES : To determine whether intravaginal clindamycin cream reduces the incidence of abnormal pregnancy outcome in women with abnormal vaginal microbial flora grade d as intermediate or BV and to investigate the effect of the antibiotic on vaginal microbial flora . METHODS : A prospect i ve cohort study of pregnant women in an antenatal clinic of a district general hospital . The subjects were 268 women who had abnormal vaginal microbial flora at first clinic visit by examination of a Gram-stained vaginal smear and 34 women with a normal vaginal flora . Two hundred and thirty-seven women were evaluable . Women with abnormal Gram-stained smears ( grade d as II or III ) on clinic recall were r and omised to receive treatment ( intravaginal clindamycin cream ) or placebo and followed to assess outcome of pregnancy , vaginal flora , and detection of Mycoplasma hominis and Ureaplasma urealyticum after treatment . RESULTS : Abnormal outcomes of pregnancy were not significantly different in treated and placebo groups by Chi square ( P = 0.2 ) . However , women with grade III flora responded better to clindamycin than women with grade II flora by numbers of abnormal outcomes ( P = 0.03 ) and return to normal vaginal flora ( P = 0.01 ) ( logistic regression analysis model ) . This may be due to differences in vaginal bacterial species in these grade s. Women whose abnormal vaginal flora had spontaneously returned to normal on follow-up and were therefore not treated ( revertants ) had as many abnormal outcomes as placebos suggesting that damage by abnormal bacterial species occurred early in pregnancy . CONCLUSIONS : Gram-stain screening distinguishing grade II from grade III flora may be helpful in prescribing treatment other than clindamycin for women with grade II flora . Earlier diagnosis and treatment may be more effective in preventing an abnormal outcome , possibly as soon as pregnancy is diagnosed or even offered as a pre-conception screen Abstract Objective To evaluate whether a screening strategy in pregnancy lowers the rate of preterm delivery in a general population of pregnant women . Design Multicentre , prospect i ve , r and omised controlled trial . Setting Non-hospital based antenatal clinics . Participants 4429 pregnant women presenting for their routine prenatal visits early in the second trimester were screened by Gram stain for asymptomatic vaginal infection . In the intervention group , the women 's obstetricians received the test results and women received st and ard treatment and follow up for any detected infection . In the control group , the results of the vaginal smears were not revealed to the caregivers . Main outcome measures The primary outcome variable was preterm delivery at less than 37 weeks . Secondary outcome variables were preterm delivery at less than 37 weeks combined with different birth weight categories equal to or below 2500 g and the rate of late miscarriage . Results Outcome data were available for 2058 women in the intervention group and 2097 women in the control group . In the intervention group , the number of preterm births was significantly lower than in the control group ( 3.0 % v 5.3 % , 95 % confidence interval 1.2 to 3.6 ; P = 0.0001 ) . Preterm births were also significantly reduced in lower weight categories at less than 37 weeks and ≤ 2500 g. Eight late miscarriages occurred in the intervention group and 15 in the control group . Conclusion Integrating a simple infection screening programme into routine antenatal care leads to a significant reduction in preterm births and reduces the rate of late miscarriage in a general population of pregnant women In a prospect i ve study of 202 women ( gestational age 24 + /- 4 weeks ) , we evaluated possible influences of lower genital tract infection or bacterial conditions on  obstetric outcomes  , including  preterm labor , preterm premature rupture of membranes , and preterm birth .  The presence of bacterial vaginosis ( 18.7 % ) was associated with an increased risk of preterm labor ( relative risk , 2.6 ; 95 % confidence interval , 1.08 to 6.46 ) . For women with bacterial vaginosis who also had Mobiluncus species morphotypes identified on Gram stain , the relative risk of preterm labor was 3.8 ( 95 % confidence interval , 1.32 to 11.5 ) . Presence of vaginal Mycoplasma hominis ( 10.8 % of patients ) was associated with both preterm labor ( relative risk , 1.8 ; 95 % confidence interval , 0.77 to 4.4 ) and preterm birth ( relative risk , 5.1 ; 95 % confidence interval , 1.45 to 17.9 ) . Recovery of Staphylococcus aureus ( 3.0 % ) was associated with preterm labor ( relative risk , 3.1 ; 95 % confidence interval 1.12 to 8.7 ) . Identification of two or more bacterial-linked abnormalities was also associated with preterm labor ( relative risk , 3.3 ; 95 % confidence interval , 1.44 to 7.58 ) . An increased level of vaginal wash protease ( greater than or equal to 10 trypsin units ) ( 16 % ) was associated with preterm labor and was noted in 50 % of women with preterm premature rupture of membranes . A history of prior preterm birth was the single best historical predictor of both preterm labor ( relative risk , 3.6 ; 95 % confidence interval , 1.92 to 6.83 ) and preterm birth ( relative risk , 6.7 ; 95 % confidence interval , 2.2 to 20.4 ) . History of three or more abortions , antenatal urinary tract infection , and occurrence of medical complications during pregnancy also correlated with increased risk of preterm labor . These findings affirm and refine associations of various maternal reproductive tract infections with preterm labor , premature rupture of membranes , and birth , allowing for controlled treatment trials aim ed at prevention of preterm birth OBJECTIVE To assess the ability of clindamycin vaginal cream to reduce the incidence of preterm birth in women with abnormal genital tract flora in the second trimester of pregnancy . METHODS This was a r and omized , double-blind , placebo-controlled , tricenter study . A total of 409 women with abnormal genital tract flora on Gram stain of vaginal secretions at 13–20 weeks ' gestation were r and omized to receive a 3-day course of clindamycin vaginal cream or placebo . Those women who still had abnormal vaginal flora 3 weeks later received a 7-day course of the original study drug ( ie , either clindamycin vaginal cream or placebo as per original r and omization ) . The primary outcome measure was the incidence of preterm birth . RESULTS There was a statistically significant reduction in the incidence of preterm birth in the clindamycin vaginal cream group ( 4 % ) compared with placebo ( 10 % ) ( P < .03 ) . Significantly more babies born preterm ( 63 % ) required admission to the neonatal intensive care unit compared with term infants ( 4 % ) ( P < .001 ) . CONCLUSION A 2 % clindamycin vaginal cream , when compared with placebo administered to women with abnormal genital tract flora before 20 weeks ' gestation , can reduce the incidence of preterm birth by 60 % and hence the need for neonatal intensive care OBJECTIVE To compare the efficacy of oral versus vaginal metronidazole treatment in pregnant women with bacterial vaginosis , and to compare cytokine profiles ( interleukin-1β , -6 , and -8 ) in the cervical secretions of these women before and after treatment . METHODS Pregnant women with bacterial vaginosis diagnosed both by Gram stain and clinical criteria were r and omized to receive oral ( n = 52 ) or vaginal ( n = 50 ) metronidazole therapy . Cervical specimens for cytokine analysis and vaginal fluid for evaluation of bacterial vaginosis were obtained at baseline and 4 weeks after treatment . RESULTS There was no significant difference in therapeutic cure rates ( defined as a Gram stain score of 0–3 and the absence of all four clinical signs of bacterial vaginosis ) between the two groups ( 71 % and 70 % for the oral and vaginal groups , respectively , P = 1.0 ) . Cervical levels of interleukin-1β , -6 , and -8 were significantly lower after treatment among the 72 women cured of bacterial vaginosis ( P < .001 , P = .001 , and P = .02 , respectively ) but not among women who failed to respond to therapy . For interleukin-1β and -6 , a significant decrease in cytokine level was observed in both the oral and vaginal treatment groups . CONCLUSION One week of oral metronidazole and 5 days of intravaginal metronidazole are equally efficacious for treatment of bacterial vaginosis during pregnancy . The decrease in cervical interleukin-1β , -6 , and -8 levels among women who established a normal flora after treatment but not among those with persistent bacterial vaginosis suggests a direct linkage between vaginal flora abnormalities and elevated cervical levels of interleukin-1β , -6 , and -8 In a previous study from this institution , patients at high risk for preterm labour were screened for the presence of bacterial vaginosis ( BV ) . When BV was present , they were r and omised to receive either treatment ( metronidazole ) or placebo ( vitamin C ) . There were significantly more patients with preterm labour in the metronidazole group . The aim of this double-blind r and omised placebo-controlled trial study was to determine whether vitamin C could indeed reduce the recurrence risk of preterm labour .  Patients with a history of preterm labour in a preceding pregnancy were r and omised to receive 250 mg vitamin C or a matching placebo twice daily until 34 weeks ' gestation . They attended a dedicated premature labour clinic . Significantly more women delivered before term in the group that received vitamin C , but there was no difference in the outcome of the babies between the two groups . Supplementation with vitamin C did not prevent premature labour Background Bacterial vaginosis ( BV ) is a common condition that is associated with preterm birth and acquisition of complex communities of vaginal bacteria that include several fastidious species . Treatment of BV in pregnancy has mixed effects on the risk of preterm delivery , which some hypothesize is due to variable antibiotic efficacy for the fastidious bacteria . Both oral and intravaginal metronidazole can be used to treat bacterial vaginosis in pregnancy , but little is known about the impact of different routes of antibiotic administration on concentrations of fastidious vaginal bacteria . Methods This was a sub- study of a larger r and omized trial of oral versus vaginal metronidazole for treatment of BV in pregnancy . Fifty-three women were evaluated , including 30 women who received oral metronidazole and 23 who received intravaginal metronidazole .  Bacterial taxon-specific quantitative PCR assays were used to measure concentrations of bacterial vaginosis associated bacterium ( BVAB ) 1 , 2 , and 3 , Gardnerella vaginalis , Atopobium species , Leptotrichia/Sneathia species , Megasphaera species , and Lactobacillus crispatus before and after antibiotic treatment . Results Concentrations of Leptotrichia and Sneathia spp . and the fastidious Clostridia-like bacterium design ated BVAB1 decreased significantly with oral ( p = .002 , p = .02 ) but not vaginal therapy ( p = .141 , p = .126 ) . The fastidious bacterium BVAB3 did not significantly decrease with either treatment . Concentrations of Atopobium spp . , reportedly resistant to metronidazole in vitro , dropped significantly with oral ( p = .002 ) and vaginal ( p = .001 ) treatment . There was no significant difference in the magnitude of change in bacterial concentrations between oral and vaginal treatment arms for any of the bacterial species . Lactobacillus crispatus concentrations did not change . Conclusion Both oral and vaginal metronidazole therapy in pregnant women result in a significant decrease in concentrations of most BV-associated anaerobic bacteria , with the exception that Leptotrichia , Sneathia and BVAB1 do not significantly decrease with vaginal metronidazole therapy . These data suggest that the route of antibiotic administration has a minor impact on bacterial eradication in pregnant women with BV.Trail Registration This trial is registered with Clinical Trials.gov , number OBJECTIVE The pathogenesis of preterm birth and other adverse pregnancy outcomes linked with reproductive tract infection remains poorly understood . Mucolytic enzymes , including mucinases and sialidases ( neuraminidase ) , are recognized virulence factors among enteropathogens and bacteria that cause periodontal infection . Perturbation of maternal cervicovaginal mucosa membrane host defenses by such enzyme-producing microorganisms may increase the risk of sub clinical intrauterine infection during pregnancy and thus increase risks of preterm birth . STUDY DESIGN We prospect ively evaluated vaginal fluid mucinase and sialidase and selected cervicovaginal bacteria along with pregnancy outcomes in 271 women . Within this study , women with bacterial vaginosis ( 16 
    Output:
    
Antibiotic treatment can eradicate bacterial vaginosis in pregnancy .
The overall risk of PTB was not significantly reduced .
This review provides little evidence that screening and treating all pregnant women with bacterial vaginosis will prevent PTB and its consequences .