Fetal Bladder Volume by Ultrasound Measurement

Why Is This Test Done?

Your healthcare provider may recommend this test if you’re at higher risk for conditions like oligohydramnios (low amniotic fluid) or if you’ve had previous complications with bladder issues. It can also be part of routine fetal monitoring in certain pregnancies.

What to Expect During the Test

You’ll lie on an exam table while a technician applies a gel to your abdomen. A transducer (probe) is placed on your skin to send sound waves that create images of your baby’s bladder. The test usually takes about 15–30 minutes and is painless.

Preparation and Timing

No special preparation is needed, but your provider may schedule it during a specific trimester (often around 20–30 weeks). Drink plenty of fluids before the test if advised, but avoid urinating right before to help visualize the bladder clearly.

What the Results Mean

Results are interpreted as either normal (within expected range for gestational age) or abnormal (e.g., too small or too large). Low bladder volume may signal dehydration or other concerns, while very high volumes could warrant further evaluation.