Hello @rose53,

Good question! D.E.S. was a hormone treatment that was given to pregnant women who were at high risk for a miscarriage, premature labor, etc. Here is a link to an article about DES from the website of National Cancer Institute website, https://www.cancer.gov/about-cancer/causes-prevention/risk/hormones/des-fact-sheet.

It's use was ended in 1971.