a procedure followed in making a medical diagnosis

using the reflections of high-frequency sound waves to construct an image of a body organ (a sonogram); commonly used to observe fetal growth or study bodily organs

(pregnancy) extraction by centesis of amniotic fluid from a pregnant woman (after the 15th week of pregnancy) to aid in the diagnosis of fetal abnormalities

prenatal diagnosis that allows direct observation of a fetus in the uterus and the withdrawal of fetal blood