Can drinking water one hour before an ultrasound increase amniotic fluid?

Under normal circumstances, drinking water one hour before a B-ultrasound does not increase amniotic fluid, as there is no direct connection between the two. The detailed explanation is as follows:

The formation of amniotic fluid is related to factors such as fetal urine, placental secretion, and membrane permeability. Its volume and composition are regulated by hormonal levels during pregnancy and the developmental status of the fetus. Amniotic fluid production cannot be altered by drinking water in a short period. Drinking water one hour before a B-ultrasound primarily increases maternal blood circulation and affects the urinary system, leading to increased urine output rather than directly converting into amniotic fluid.

The main purpose of drinking water is to fill the bladder. A full bladder pushes the intestines aside, reducing interference from intestinal gas on ultrasound imaging and allowing clearer visualization of organs such as the uterus and ovaries, making it easier for doctors to examine them. This is not done to increase amniotic fluid. Even with excessive water intake, only maternal blood volume may temporarily increase—amniotic fluid levels cannot rise quickly. On the contrary, overfilling the bladder may cause discomfort during the examination.

If low amniotic fluid is detected during examination, long-term management under medical guidance—such as regular hydration and nutritional supplementation—is required. Simply drinking water shortly before the test will not help. Before undergoing a B-ultrasound, individuals should drink an appropriate amount of water according to the specific requirements of the examination area, avoiding excessive or blind water intake, staying relaxed, and ensuring the examination proceeds smoothly.