Purpose: This hospital-based study has determined the change over time (1972-1974 and 1979-1994) in the methods of prenatal detection of fetuses with Down syndrome and the impact of elective termination on the portion that were liveborn.
Methods: Using a malformations surveillance program, all 265 affected fetuses and infants were identified among 161,560 births and elective terminations during the aforementioned period at Brigham and Women's Hospital in Boston, MA.
Results: From 1972 to 1974, Down syndrome was not diagnosed in any affected infants prenatally. In the early 1980s, amniocentesis was the primary method of diagnosis; later, maternal serum screening and ultrasonography were as likely to be the first method of detection. Most couples (86%) elected to terminate pregnancies with affected fetuses.
Conclusions: The effect of prenatal detection and the choice of elective termination produced a significant decrease, between 1972 and 1994, in the portion of fetuses with Down syndrome who were liveborn.