Collecting a urine sample from an infant girl who is not yet toilet-trained presents a significant challenge for parents and caregivers. The use of a pediatric urine collection bag, often called a U-bag, provides a non-invasive method to obtain a timely sample for diagnostic evaluation. This specimen is typically needed to perform a urinalysis, which can help a healthcare provider screen for conditions like dehydration or a urinary tract infection (UTI). While this method is generally simpler than a catheterization, meticulous technique is required to prevent contamination that could skew the test results.
Preparing the Supplies and the Infant
Gather all necessary materials, including the sterile urine collection bag, a separate sterile specimen container, mild soap or cleansing wipes, clean water, and a towel. Thoroughly wash your hands with soap and water to minimize the transfer of bacteria onto the infant or the supplies, ensuring the genital area is as clean as possible, since residual bacteria or fecal matter will contaminate the collected urine.
Lay the infant on her back and remove the diaper, ensuring the immediate area is free of any stool. Use the mild soap or a sterile wipe to gently clean the entire genital region, separating the skin folds (labia) to access all surfaces. Always wipe from the front toward the back to avoid dragging bacteria from the anal area over the urethra.
Rinse the area with clean water and pat it completely dry with a clean towel, as the collection bag’s adhesive will not stick properly to moist skin. Avoid using any lotions, oils, or baby powders on the perineum, as these residues can interfere with the adhesive seal and potentially contaminate the sample.
Step-by-Step Guide to Bag Placement
To apply the collection bag, carefully peel the protective paper backing from the adhesive collar around the opening of the bag. It can be easiest to remove only the bottom half of the backing first, leaving the top portion covered until the initial placement is secured. With the infant lying still, gently separate the labia majora to fully expose the urinary opening (meatus).
Positioning the bag correctly captures the urine while preventing contact with the anus. Start by securing the lower edge of the adhesive to the tiny area of skin between the vagina and the anus, which is known as the perineum. This starting point helps to ensure the bag is positioned far enough back to avoid fecal contamination while still covering the urinary meatus.
Once the bottom is secured, peel away the rest of the backing and work upward, pressing the adhesive collar firmly against the skin around the labia. The entire external genitalia should be contained within the bag’s opening, with the adhesive forming a tight seal on all sides.
After the bag is securely attached, place a clean diaper loosely over the infant and the collection bag. The bag should hang freely inside the diaper without being pulled or distorted, which could break the adhesive seal. Monitoring should begin immediately, as the urine collection must be completed quickly.
Removing the Bag and Handling the Sample
While the collection bag is attached, monitor the infant closely, checking the bag every 15 to 20 minutes, as an active infant can dislodge the seal. Once an adequate amount of urine is visible in the bag—typically a minimum of 1 to 2 milliliters—the bag should be removed promptly to prevent contamination or leakage. To remove it, gently hold the surrounding skin taut and slowly peel the adhesive away from the skin.
After removal, immediately seal the collection bag by pressing the adhesive sides together to contain the urine. The collected urine must then be transferred into the sterile specimen container provided by the healthcare provider. To do this, hold the sealed collection bag over the open container and cut a small corner or pull the designated tab at the bottom of the bag, allowing the urine to drain completely into the cup.
Once the urine is transferred, tightly screw the lid onto the sterile container, touching only the outside of the cup and lid. This bag-collected sample is generally appropriate for a preliminary urinalysis, but it is often considered contaminated for the purpose of a formal urine culture used to definitively diagnose a UTI. The high risk of skin bacteria entering the bag means that a positive culture result is unreliable and often requires a more invasive collection method, such as catheterization, for confirmation.
The sample must be delivered to the laboratory within a strict timeframe, usually 30 to 60 minutes after collection. If immediate transport is not possible, the specimen should be placed inside a sealed plastic bag and refrigerated to slow bacterial growth. Be sure to clearly label the container with the infant’s full name, date of birth, and the exact date and time of collection.