This guideline is intended for situations where 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 aspiration should be attempted. This should be performed prior to handling the baby for any other invasive procedure. The method is as described in any major Paediatric text.
2. If this is unsuccessful and other investigations can be delayed, a cloth nappy should be put on and the aspiration re-attempted after 30-45 minutes as long as the nappy is still dry.
3. If no urine has been collected after two attempts at 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. A suitably sized plastic tube should be used. This would most commonly be a 5 French feeding tube or a 3.5 umbilical catheter.
5. If difficulties are encountered passing the catheter, particularly in a baby boy, the catheter should not be forced because of the risk of urethral trauma.
6. Ideally the first couple of drops of urine from the catheter should be discarded and the remainder collected for analysis.