Urinalysis & Urine Culture
A urine test examines the physical, chemical and microscopic features of your urine. It is one of the simplest and most useful tests in medicine, because urine reflects the health of the kidneys and urinary tract and can reveal infection, diabetes and certain complications of pregnancy. When an infection is suspected, a urine culture identifies the germ and the antibiotics that will work against it.
At YGOPH, urine is tested at antenatal visits to detect protein, a warning sign of pre-eclampsia, and sugar. Pregnant women are also screened for infections that may cause no symptoms but can lead to preterm labour, and children with an unexplained fever are tested for urinary tract infection, a common and treatable cause.
What do urinalysis and urine culture involve?
Urinalysis starts with a reagent strip (dipstick) that changes colour in the presence of protein, glucose, blood, white cells, nitrites or ketones. The urine is then examined under the microscope for cells, crystals and bacteria. A urine culture (ECBU) places a drop of urine on a growth medium to see whether bacteria multiply; if they do, the laboratory identifies them and tests which antibiotics are effective (antibiogram).
- Burning or frequent urination, lower abdominal pain or fever
- Routine antenatal care, to detect protein, sugar and infection
- Unexplained fever, poor feeding or vomiting in babies and young children
- High blood pressure or swelling in pregnancy
- Follow-up of diabetes and kidney disease
- Checking that an infection has cleared after treatment
Good to know
Urinalysis (dipstick and microscopy)
The dipstick gives results within minutes and is often done during the consultation. Laboratory microscopy adds detail, such as the number of white and red cells and the presence of casts or crystals. Protein in the urine of a pregnant woman with high blood pressure needs urgent attention, as it may indicate pre-eclampsia.
Urine culture and antibiogram
The culture usually takes 48 to 72 hours: about 24 hours for bacteria to grow, then further time to identify them and test antibiotics. A positive culture confirms infection and guides treatment, which matters because resistance to common antibiotics is increasing. A sample taken after antibiotics have started may give a falsely negative result.
Collecting a good sample
Wash your hands and the genital area with water, start urinating into the toilet, then collect the middle part of the stream in the sterile container and close it without touching the inside. For babies, the nurse may use a sterile collection bag or a clean catch. Bring the sample to the laboratory within one hour.