Frequent Urination in Early Pregnancy: Causes & What to Expect

Frequent urination often begins by 6 weeks gestation. Causes:

• hCG: Increases pelvic blood flow and renal plasma flow → ↑ GFR → ↑ urine output.
• Progesterone: Relaxes ureteral/bladder smooth muscle → reduced bladder tone, earlier urge sensation.
• Uterine pressure: Even early, the enlarging uterus presses on bladder.
• Fluid retention: Increased total body water.

Symptom often improves in second trimester as uterus rises out of pelvis, but returns late pregnancy from fetal head engagement. No treatment needed unless dysuria, fever, or flank pain suggest UTI (common in pregnancy).