Why do pregnant women get urinary tract infections?

Progesterone: The hormone Progesterone starts to go up pretty early in the pregnancy. It slows done the urine system and makes a woman more predisposed to urinary tract infections.

2 reasons: 1) pregnancy is associated with greatly increased levels of circulating estrogen, which in turn causes ureters and bladder to enlarge temporally + reduces force of smooth muscle contraction and impaired ureteral and bladder emptying. 2) enlaging uterus pushes bladder forward causing possible obstruction at bladder neck and impaired emptying. Retention of urine predisposes subjects to develop utis.