Diethylstilbestrol, or DES, was the first synthetic estrogen. It was developed in 1938 by English biochemist Sir E. Charles Dodds. Two Harvard University physicians, George and Olive Smith, were the first to recommend DES as the ideal drug to prevent miscarriage. In 1948, they published a paper that aroused great enthusiasm in the medical community. Easy to produce, cheap and promising, DES was prescribed to millions of pregnant women in Canada and the United States.

In 1952, the first study appeared that cast doubt on the safety and effectiveness of DES for use in pregnancy. A second study scientifically proved that DES was ineffective in high-risk pregnancies. In fact, DES appeared to increase the chances of miscarriage. It was not until 1971, with the publication of a paper directly linking DES to the occurrence of vaginal cancer in daughters whose mothers were prescribed it, that the drug was taken off the Canadian market, 33 years after it was first developed.

The harmful effects of the drug are still being felt by thousands of DES children and grandchildren. Scientists are continuing to explore the health effects of DES on those who have been exposed to it, and unfortunately, there is no end in sight.