How is an asymptomatic UTI in pregnancy typically diagnosed?

The diagnosis of an asymptomatic urinary tract infection (UTI) in pregnancy is primarily confirmed through bacterial culture, which demonstrates the presence of a significant amount of bacteria in the urine, typically defined as 100,000 colony-forming units per milliliter. This threshold is important because it indicates a significant infection that requires treatment, even in the absence of symptoms, to prevent complications such as pyelonephritis or adverse pregnancy outcomes.

Bacterial cultures are the gold standard for diagnosing UTIs because they provide definitive evidence of the presence of pathogenic organisms, which can then be targeted appropriately with antibiotics. The other options provided do not reliably diagnose asymptomatic UTIs. For instance, glucose in the urine could indicate conditions like gestational diabetes rather than a UTI. Routine appointment assessments may suggest further testing but do not serve as diagnostic confirmation on their own. CT scans are generally avoided during pregnancy unless absolutely necessary due to the potential risks to the fetus and are not used for diagnosing UTIs.

Thus, the correct method for diagnosing an asymptomatic UTI in pregnancy hinges on the presence of bacteria at significant levels in a culture test.