***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: The presence of group-B streptococci in the urine of pregnant women seems to be associated with preterm labour . Urine sample s from 4122 women at 27 - 31 weeks ' gestation were examined for bacteria . Group-B streptococci were found in the urine of 69 women . In a double-blind , controlled study these patients were given either penicillin ( 10(6 ) IU three times daily for 6 days ; 37 patients ) or placebo ( 32 patients ) . The rates of primary rupture of the membranes ( 11 % v 53 % ; p less than 0.001 ) and preterm labour ( 5.4 % v 38 % ; p less than 0.002 ) were significantly lower in the penicillin group than in the placebo group . These results suggest that treatment and follow-up to prevent recolonisation in pregnant women with group-B streptococci in the urine may reduce the frequency of preterm labour in these patients BACKGROUND Existing approaches for the screening and treatment of asymptomatic bacteriuria in pregnancy are based on trials that were done more than 30 years ago . In this study , we reassessed the consequences of treated and untreated asymptomatic bacteriuria in pregnancy . METHODS In this multicentre prospect i ve cohort study with an embedded r and omised controlled trial , we screened women ( aged ≥18 years ) at eight hospitals and five ultrasound centres in the Netherl and s with a singleton pregnancy between 16 and 22 weeks ' gestation for asymptomatic bacteriuria . Screening was done with a single dipslide and two culture media . Dipslides were judged positive when the colony concentration was at least 1 × 10(5 ) colony-forming units ( CFU ) per mL of a single microorganism or when two different colony types were present but one had a concentration of at least 1 × 10(5 ) CFU per mL. Asymptomatic bacteriuria-positive women were eligible to participate in the r and omised controlled trial comparing nitrofurantoin with placebo treatment . In this trial , participants were r and omly assigned 1:1 to receive either nitrofurantoin 100 mg or identical placebo tablets , and were instructed to self-administer these tablets twice daily for 5 consecutive days . R and omisation was done by a web-based application with a computer-generated list with r and om block sizes of two , four , or six participants rendered by an independent data manager . 1 week after the end of treatment , they provided us with a follow-up dipslide . Women , treating physicians , and research ers all remained unaware of the bacteriuria status and treatment allocation . Women who refused to participate in the r and omised controlled trial did not receive any antibiotics , but their outcomes were collected for analysis in the cohort study . We compared untreated and placebo-treated asymptomatic bacteriuria-positive women with asymptomatic bacteriuria-negative women and nitrofurantoin-treated asymptomatic bacteriuria-positive women . The primary endpoint was a composite of pyelonephritis with or without preterm birth at less than 34 weeks , analysed by intention to treat at 6 weeks post-partum . This trial is registered with the Dutch Trial Registry , number NTR3068 . FINDINGS Between Oct 11 , 2011 , and June 10 , 2013 , we enrolled 5621 women into our screening cohort , of whom 5132 were eligible for screening . After exclusions for contaminated dipslides and patients lost to follow-up , in our final cohort of 4283 women , 248 were asymptomatic bacteriuria positive , of whom 40 were r and omly assigned to nitrofurantoin and 45 to placebo for the r and omised controlled trial , whereas the other 163 asymptomatic bacteriuria-positive women were followed without treatment . The proportion of women with pyelonephritis , preterm birth , or both did not differ between untreated or placebo-treated asymptomatic bacteriuria-positive women and asymptomatic bacteriuria-negative women ( 6 [ 2·9 % ] of 208 vs 77 [ 1·9 % ] of 4035 ; adjusted odds ratio [ OR ] 1·5 , 95 % CI 0·6 - 3·5 ) nor between asymptomatic bacteriuria-positive women treated with nitrofurantoin versus those who were untreated or received placebo ( 1 [ 2·5 % ] of 40 vs 6 [ 2·9 % ] of 208 ; risk difference -0·4 , 95 % CI -3·6 to 9·4 ) . Untreated or placebo-treated asymptomatic bacteriuria-positive women developed pyelonephritis in five [ 2·4 % ] of 208 cases , compared with 24 [ 0·6 % ] of 4035 asymptomatic bacteriuria-negative women ( adjusted OR 3·9 , 95 % CI 1·4 - 11·4 ) . INTERPRETATION In women with an uncomplicated singleton pregnancy , asymptomatic bacteriuria is not associated with preterm birth . Asymptomatic bacteriuria showed a significant association with pyelonephritis , but the absolute risk of pyelonephritis in untreated asymptomatic bacteriuria is low . These findings question a routine screen-treat-policy for asymptomatic bacteriuria in pregnancy . FUNDING ZonMw ( the Netherl and s Organisation for Health Research and Development ) A screening programme for the detection of asymptomatic bacteriuria in patients attending an antenatal clinic is described . The results obtained from the use of urinary antiseptics in a controlled trial over a period of two years are presented . The number of patients developing clinical pyelonephritis , fetal maturity at delivery and birth weight  were recorded for treatment and control groups and compared with the equivalent results obtained from the total population of patients seen at the clinic The first part consisted of a prospect i ve study dealing with a series of 170 pregnancies during which cyto-bacteriological examination of urine was carried out in the 3rd , 5th , 7th and 9th months of pregnancy . Whenever bacteriuria was found it was treated . Those women found to be infected in pregnancy were re-examined bacteriologically and radiologically after delivery . A control series consisted of 200 pregnant women whose urines were not examined in this way unless they had clinical signs . In the first series 39 out of 170 women had at least one positive cyto-bacteriological test . 56 out of 638 examinations were abnormal . 50 had asymptomatic bacteriuria . No patient had any sign of acute pyelonephritis . In the control series 16 of the women had at least one positive cyto-bacteriological test . In all 21 tests were carried out ( 18 before signs of cystitis developed and 3 before symptoms of acute pyelonephritis ) . Treating asymptomatic bacteriuria is worth while because it helps to lower the incidence of pyelonephritis . There did not seem to be any relationship between premature labour , fetal mortality and maternal urinary pathology . Tests carried out at two definite intervals in pregnancy would seem to be a sufficient screening for preventing pyelonephritis and would be acceptable from the cost angle Although asymptomatic bacteriuria during pregnancy is associated with an increased risk of developing pyelonephritis , the effectiveness of screening programs to reduce this risk is controversial . A sharp reduction in the annual incidence of pyelonephritis ( 1.8 % to 0.6 % , P < .001 ) occurred after the introduction of a program to screen and treat asymptomatic bacteriuria among pregnant women followed at a large teaching hospital . The data provide retrospective and prospect i ve evidence that screening and treatment programs for asymptomatic bacteriuria during pregnancy reduce the risk of pyelonephritis in a population with a moderate to high prevalence of bacteriuria The incidence of impaired renal concentrating ability in pregnant women with asymptomatic significant bacteriuria is significantly less than previously reported when osmolality readings are performed on every urine specimen obtained during the 24 hours ' deprivation of fluids . The concentrating defect is more considerable as pregnancy progresses . The lower the maximum urinary osmolality the more difficult is the treatment of the patient , and the higher the incidence of acute pyelonephritis Although it has been shown that  bacteriuria of pregnancy  can be eradicated by keeping patients on antibacterial agents throughout pregnancy [ 1 ] , this regimen of treatment would be unacceptable to most individuals , particularly when asymptomatic ; and there are many who would question the ethical justification for such prolonged antibacterial therapy in pregnancy . This paper presents the results of a study design ed to determine whether antibacterial therapy of limited duration would eradicate 
    Output:
    
Women have conflicting opinions about antibiotic use during pregnancy .
Antibiotic treatment for women having significant bacteriuria likely reduces the incidence of pyelonephritis and low birth weight , but we are uncertain about the magnitude of the effect and about the extent to which we can apply these results to asymptomatic population s and screening programmes .