This guideline is intended for situations where antibiotic therapy needs to be commenced within two days. For other purposes, e.g. monitoring for infection in asymptomatic infants with renal tract anomalies, infection screen in 'well' infants with risk factors, a bag urine may suffice if negative on culture.

1. A suprapubic bladder aspiration should be attempted. This is considered a reliable method of obtaining urine for culture in infants. This should be performed prior to handling the baby for any other invasive procedure. The method is as described in McDonald & Ramasethu (2009).
2. If this is unsuccessful and other investigations can be delayed, replace the infant's nappy and reattempt suprapubic aspiration after 30-45 minutes provided that the nappy is still dry.
3. If no urine has been collected after two attempts at suprapubic aspiration of if therapy needs to be commenced urgently, then a collection by urethral catheterisation should be attempted.
4. Catheterisation should be performed by a member of the medical or nursing staff who is familiar with the technique (see urinary catheterisation protocol). An appropriate sized urinary catheter or if not available size 5 French feeding tube or 3.5 umbilical catheter (in that order of preference) should be used. Try to use the smallest-diameter catheter to avoid traumatic complications.
5. If the catheter does not pass easily, particularly in a baby boy, do not use force because of the risk of urethral trauma.
6. Collect specimen for culture. Remove the catheter as soon as possible to avoid infectious complications.

N.B Feeding Tubes are not to be left insitu.

Reference:

Suprapubic Bladder Aspiration and Bladder Catheterization, In: Atlas of Procedures in Neonatalogy (4th Ed). MacDonald, G.M. & Ramasethu, J. (Eds), 2009, (pp 108-116).