ASB treat study.

Main primary outcomes are a composite endpoint of pyelonephritis and preterm delivery (< 34 weeks). Pyelonephritis will be defined as an episode of fever, clinical symptoms and a positive urine culture.

Secondary outcome measure is adverse neonatal condition (death or severe morbidity). This composite morbidity rate contains the following variables: Severe Respiratory Distress Syndrome (RDS), Bronchopulmonary Dysplasia (BPD), Intraventricular Haemorrhage grade II B or worse, Necrotizing Enterocolitis (NEC), proven sepsis and death before discharge from the nursery.18 They will be measured until 10 weeks after the expected term date.


Other parameters are: Neonatal weight, time to delivery, preterm birth rate before 32 and 37 weeks, presence of chorioamnionitis, days of admission in neonatal intensive care unit, maternal morbidity (including UTI), maternal admission days for preterm labour and costs.

Moreover, we will look at growth, physical condition and neurodevelopmental outcome of the offspring at 24 months (corrected) age. If possible, we will stratify for cervical length.

Next to secondary clinical outcome, the cost-effectiveness of screening for asymptomatic bacteriuria (as done in triple P/ ASB screening), and subsequent treatment in case of ASB, will be assessed.