Historical aspects of genetic counseling: why was maternal age 35 chosen as the cut-off for offering amniocentesis?

The justification for offering amniocentesis to women age 35 or older is that by age 35 the risk of having a child with chromosome problem is greater than the risk of amniocentesis. In fact, this seemingly objective statement is not supported by historical analysis. Maternal age 35 was chosen for the cutoff based mostly on economic cost-benefit analysis rather than objective medical assessment. The story of why 35 was chosen illustrates how collective memory can affect, and be influenced by, the guiding ethical principles of a medical profession.