Fetal Bladder Size: Development & Normal Dimensions by Week

The normal size of the bladder in a fetus varies depending on the stage of development. Here are some general guidelines:

1. First trimester: During the first trimester, the bladder is relatively small and begins to develop around week 5 of gestation. It appears as a small, fluid-filled sac located in the lower abdomen.
2. Second trimester: As the fetus grows during the second trimester, the bladder also increases in size. By week 18 of gestation, the bladder is typically around 2-3 centimeters in diameter.
3. Third trimester: During the third trimester, the bladder continues to grow and reach its full size. By week 36 of gestation, the bladder is usually around 4-5 centimeters in diameter.

The size of the fetal bladder can be monitored through routine ultrasound examinations during pregnancy. It is important to note that these measurements can vary between individual fetuses, and the size of the bladder may fluctuate during pregnancy. If there are concerns about the size or development of the fetal bladder, your doctor may recommend additional imaging studies or evaluations.