More and more medical technologies are becoming available for the early detection of congenital abnormalities, such as amniocentesis, chorionic villus sampling, and ultrasound scanning. Recent research has shown that maternal serum can provide a wealth of information on the unborn fetus and that the testing method lends itself to mass screening. Although screening will prevent a great deal of grief, such developments also lead to extreme medicalization of pregnancy. However, owing to the fact that people show a strong desire to avert every possible approaching calamity, the "tentative pregnancy" seems to be unavoidable.