The purpose of this study is to determine the amount of cranberry juice that is most effective in preventing a condition in pregnant women that often leads to urinary tract infections (UTIs).

Asymptomatic bacteriuria (ASB) infection, a condition in which a large number of bacteria are present in the urine, often precedes the development of symptomatic UTIs. UTIs are common among women and may create complications during pregnancy. By incorporating cranberry juice into their diets, pregnant women may be able to lower their risk for UTIs caused by ASB, and cranberry juice may also prevent preterm labor and birth. This study will determine the cranberry juice-containing regimen that will work best for preventing ASB in pregnant women.

For the duration of their pregnancy, participants in this study will be randomly assigned to one of three treatment arms: cranberry juice once a day, cranberry juice three times a day, or a placebo beverage three times a day. The level of bacteria in their urine will be measured at monthly study visits. Women who test positive for a UTI will receive oral antibiotic therapy. All women will be monitored throughout their pregnancies for UTIs and other related complications.

Inclusion Criteria:

• Intrauterine pregnancy
• Mother and fetus in good health
• Mother pregnant for 16 weeks or less

Exclusion Criteria:

• Suspected nonviable or ectopic pregnancy
• Mother plans to terminate pregnancy
• Antimicrobial therapy, for reasons other than urinary tract infections, within 2 weeks prior to study start
• Significant underlying medical complications that may interfere with the study