• infant pain response, as measured by facial grimacing and changes in heart rate and oxygen saturation during the procedure
  

• success rate of obtaining a sample suitable for analysis
  
• adverse events, such as post-procedure haematuria, haemorrhage, haematoma, peritonitis, bowel perforation, abdominal wall abscess, and induction of infection, bladder perforation, urethral knots
  
• success rate of procedure according to infant factors; gestational age and sex
  

Infants hospitalized in the NICU undergo numerous invasive and painful procedures. Exposure to early repeated painful procedures has been correlated with both short-term and long-term negative sequelae, such as altered pain responses and increased sensitivity to pain (Taddio 2005). Fifty eligible infants in the NICU will be randomized to undergo urine collection by either suprapubic aspiration (SPA) or urinary catheterization (UC). Outcome measures will include pain, procedure success, and procedure duration. Pain will be measured using facial grimacing (the infant's face will be videotaped for the entire procedure), heart rate and oxygen saturation. Procedure success will be defined by the collection of about 2mL of urine (Falcao, 1999). The procedure duration in seconds for the first attempt will be calculated. Infants will be monitored during the procedure for adverse events such as apnea, bradycardia, desaturation, emesis, increased ventilatory support. Results will be extremely valuable in aiding health care providers to choose a urine collection technique that minimizes the pain and maximizes the success of the procedure.