A comparative trial of pivmecillinam and ampicillin in bacteriuria of pregnancy. Is single-dose fosfomycin trometamol a good alternative for asymptomatic bacteriuria in the second trimesterof pregnancy? One-day compared with 7-day nitrofurantoin for asymptomatic bacteriuria in pregnancy: a randomized controlled trial. Is screening for bacteriuria in pregnancy worth while?
A comparative trial of pivmecillinam and ampicillin was performed on 100 women with bacteriuria of pregnancy. They received either 400 mg pivmecillinam four times daily or 500 mg ampicillin four times daily for seven days. Cure rates at two weeks were 88% in the pivmecillinam group and 85% in the ampicillin group. At six weeks the respective rates were 76% and 64%. Failure of therapy was not associated with the appearance of bacterial resistance in either treatment group. Side-effects, particularly vomiting and premature cessation of therapy, were significantly more frequent in the pivmecillinam group. No significant effects on liver function were found. In subsequent patients treated in a non-comparative manner with 200 mg pivmecillinam three times daily, the incidence of side effects was markedly reduced with no loss of efficacy. Untreated asymptomatic bacteriuria has been associated with acute pyelonephritis, which may have a role in many maternal and fetal complications. Acute pyelonephritis in pregnancy is related to anemia, septicemia, transient renal dysfunction, and pulmonary insufficiency. A randomized study was conducted to assess the clinical and microbiological efficacy of a single dose of fosfomycin trometamol for the treatment of asymptomatic bacteriuria in the second trimester of pregnancy compared with a 5-day regimen of cefuroxime axetyl. Forty-four women received fosfomycin trometamol and 40 women received cefuroxime axetyl. There were no statistically significant differences between both groups regarding the mean age and mean duration of pregnancy. Therapeutic success was achieved in 93.2% of the patients treated with fosfomycin trometamol vs 95% of those treated with cefuroxime axetyl. A single dose of fosfomycin trometamol is a safe and effective alternative in the treatment of asymptomatic urinary tract infections in the second trimester of pregnancy. To evaluate whether a 1-day nitrofurantoin regimen is as effective as a 7-day regimen in eradicating asymptomatic bacteriuria during pregnancy.
                A multicenter, double-blind, randomized, placebo controlled noninferiority trial was conducted in antenatal clinics in Thailand, the Philippines, Vietnam, and Argentina. Pregnant women seeking antenatal care between March 2004 and March 2007 who met the inclusion and exclusion criteria were invited to participate in the study. Those who consented were randomly allocated to receive either a 1-day or a 7-day course of 100 mg capsules of nitrofurantoin, which was taken twice daily. The primary outcome was bacteriologic cure on day 14 of treatment.
                : A total of 1,248 of 24,430 eligible women had asymptomatic bacteriuria, making the overall prevalence of 5.1%. Of these 1,248 women, 778 women were successfully recruited, and 386 and 392 women were randomly allocated to 1-day and 7-day regimens, respectively. Escherichia coli was the most common potentially pathogenic bacteria detected, its prevalence approaching 50%. Bacteriologic cure rates at treatment day 14 were 75.7% and 86.2% for 1-day and 7-day regimens, respectively. The cure rate difference was -10.5% (95% confidence interval -16.1% to -4.9%). Mean birth weight and mean gestational age at delivery were significantly lower in the 1-day regimen group. There were fewer adverse effects in the 1-day regimen group, but the differences were not statistically significant.
                A 1-day regimen of nitrofurantoin is significantly less effective than a 7-day regimen. Women with asymptomatic bacteriuria in pregnancy should receive the standard 7-day regimen.
                ISRCTN, isrctn.org, ISRCTN11966080
                I. A total of 4470 pregnant women were screened for bacteriuria by the dipslide method and significant growth found in 226 (5.1%). In 198 cases the urine was re-examined, in 119 by using suprapubic aspiration or catheterisation (62 (52%) samples contained bacteria) and in 79 by using midstream urine samples (26 (33%) samples contained greater than 10(8) colony forming units/1), showing the maximum prevalence of confirmed bacteriuria to be 2.6%. Overt urinary tract infection developed later in four of 80 patients with proved bacteriuria who had been given antibiotics, in one of eight untreated patients with bacteriuria, in one of 110 patients with unconfirmed bacteriuria, and in one of 226 non-bacteriuric controls. A history of urinary tract infection was given by 18% of controls and 42% of women with confirmed bacteriuria. Screening for bacteriuria and treatment with antibiotics to prevent later overt infection is expensive. Whether it is worth while and cost effective depends largely on the prevalence of bacteriuria in the local population and the proportion who develop overt infection. The screening and treatment programme reported here appeared to prevent only six cases of overt infection.
We cannot draw any definite conclusion on the most effective and safest antibiotic regimen for the initial treatment of asymptomatic bacteriuria in pregnancy. One study showed advantages with a longer course of nitrofurantoin, and another showed better tolerability with ampicillin compared with pivmecillinam; otherwise, there was no significant difference demonstrated between groups treated with different antibiotics. Given this lack of conclusive evidence, it may be useful for clinicians to consider factors such as cost, local availability and side effects in the selection of the best treatment option.