The investigatore decided not to proceed with this study

Background: Urinary tract infections (UTIs), the most common infection in pregnancy,are associated with several maternal and fetal complications, including maternal septic shock, preterm labor, intrauterine growth restriction and intrauterine fetal death. Thus, the prevention of UTIs in pregnancy is a very important goal. Several studies have suggested that alterations in the vaginal flora were associated with recurrent UTIs, and probiotic administrations may have a role in preventing those infections. Nevertheless, this has never been tested in pregnant women.

Background: Urinary tract infections (UTIs), the most common infection in pregnancy,are associated with several maternal and fetal complications, including maternal septic shock, preterm labor, intrauterine growth restriction and intrauterine fetal death. Thus, the prevention of UTIs in pregnancy is a very important goal. Several studies have suggested that alterations in the vaginal flora were associated with recurrent UTIs, and probiotic administrations may have a role in preventing those infections. Nevertheless, this has never been tested in pregnant women.

Working hypothesis and aims:Administration of oral probiotic formula to pregnant women,which suffered from at least one episode of UTI, will reduce the recurrence of future UTIs events.

Methods: A prospective randomized double blind placebo-control study. Pregnant women which suffered from at least one event of UTI during pregnancy will be divided into 2 research arms:

ARM A - women who suffered from one episode of UTI during pregnancy before recruitment: after antibiotic treatment achieving a sterile bacterial urine culture, these patients will be divided into a research group which will receive the probiotic formula Urex Plus containing L. rhamnosus GR-1 and L. reuteri RC-14, and a control group, which will receive a placebo, twice a day until delivery.

ARM B - women who suffered from more than one episode of UTI or one episode of pyelonephritis during pregnancy before recruitment will receive a preventive antibiotic treatment until delivery. Similarly to ARM A, after achieving a sterile bacterial urine culture, those women, will be divided into a research group, which will receive the probiotic formula Urex Plus, and a control group, which will receive a placebo twice a day until delivery.

Once a month and with symptoms, urine culture will be taken in all of the study arms. Vaginal swab test will also be taken to detect the presence of abnormal vaginal flora and semi-quantitative assessment of vaginal lactobacilli.

Data regarding the rate of recurrent UTIs, time until infection, average number of infections, the rate of pyelonephritis infections and obstetrical and neonatal outcomes will be collected.

Inclusion Criteria:

• Above 18 years old
• Pregnant women who suffered from at least one episode of UTI
• Women less than 34th week of gestation at the time of the enrollment
• Urine culture is sterile in the beginning of the study

Exclusion Criteria:

• Immunocompromised women