FTP identify this common procedure, in which fluid is extracted from the uterine sac via a long hollow needle.
It was developed in the last century to drain excess fluid, and was used in the 1930's to detect the blood disease erythroblastis fetalis.  Today it also measures alphafetoprotein in order to predict spina bifida, and can detect neural tube defect, Rh problems, Tay Sachs, Down syndrome, and the sex of the fetus.  FTP identify this common procedure, in which fluid is extracted from the uterine sac via a long hollow needle.
It was developed in the last century to drain excess fluid, and was used in the 1930
amniocentesis