A: A urinary tract infection (also known as a UTI or bladder infection) occurs in about 10% of all pregnant women. UTIs do not pose any danger to a developing fetus, and the infection is usually asymptomatic during pregnancy (unlike the pain that usually occurs when you get one in a non-pregnant state). However, untreated UTIs can progress to kidney infections, which are far more serious. Practitioners are aggressive about treating kidney infections during pregnancy because they can lead to complications that can be serious for both mom and baby. These include: (1) an infection in the bloodstream that can quickly spread to other organs (sepsis); (2) pneumonia; and (3) preterm labor. Obviously, all three complications can be dangerous, which is why your urine is checked at every prenatal visit and if an infection is detected, antibiotics are prescribed.