Maturation of vaginal and cervical epithelium in women exposed in utero to diethylstilbestrol (DESAD Project).

A total of 452 women with documented exposure in utero to diethylstilbestrol (DES) with epithelial findings present at the time of their initial examination have been evaluated prospectively to determine whether these findings changed over a period of 3 years. The examinations were all performed according to a strict protocol. Findings present at the time of the third annual examination were verified at a fourth examination. A verified decrease in the extent of epithelial findings occurred in 29.2% of these women and a verified increase in 6.6%; 53.1% had no change in the extent of epithelial findings, and 11.1% had a change that could not be verified at the time of the fourth visit. Analysis of many variables failed to identify a strong association between any variable and a decrease in the extent of the findings. It appears that the most important factor in the occurrence of changes in DES-associated findings is the passage of time.