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The DES Follow-Up Study investigates the long-term health consequences associated with exposure to diethylstilbestrol (DES). Since 1992, the National Cancer Institute, in collaboration with research centers throughout the United States has been conducting the DES Follow-Up Study of more than 21,000 mothers, daughters, and sons.

* The DES Action link is not associated with NCI.

STUDY UPDATE: Prenatal Diethylstilbestrol Exposure and High-grade Squamous Cell Neoplasia of the Lower Genital Tract

The link between prenatal DES exposure and vaginal and cervical clear cell adenocarcinoma in young women was established in the early 1970s. Parentally DES exposed women are also shown to have a two times higher risk of cervical and vaginal squamous cell neoplasia (a possible precursor to cancer) compared with unexposed women. The current analysis set out to determine whether the increased risk for squamous cell neoplasia of the vagina and cervix continued with age among the DES exposed and whether DES-exposed women should continue to receive annual Pap smears. Continue reading DES and High-grade Squamous Cell Neoplasia


Latest Follow-up Study

The sixth round of the DES Follow-up Study began in May of 2016. We want to thank all of the participants who have already returned their questionnaires. Your continued participation has allowed the investigators and scientists to continue exploring how DES has impacted your health.


Studies Underway

Thanks to your support of the DES Follow-up Study, the information you have provided, including from the most recent 2016 follow study, allows us to keep exploring the health effects of prenatal DES exposure. We are:

  • Examining the impact of prenatal DES exposure on the risk of developing:
    • cancer and other medical conditions, such as cardiovascular disease, in men and women;
    • cervical dysplasia, high breast density, benign breast disease, and breast carcinoma in situ in women; and
    • depression.

In addition, we are continuing to analyze new information from the Third Generation Study (the granddaughters study) to determine the health effects among women whose mothers were exposed to DES in utero.


Study of Genetic Markers in DES Exposed Daughters Pilot Study Completed

Researchers at the National Cancer Institute and Boston University are currently studying whether genetic markers and reproductive hormone concentrations differ between women who were and were not prenatally exposed to DES. In a small pilot study of 60 women (40 who were exposed to DES and 20 who were not) blood samples were drawn from women participating in our long-term DES Follow-up Study of the health effects of DES exposure. The samples were sent to a laboratory for measurements. The findings of this pilot study may have profound implications for the ways in which endocrine disruption (chemicals that interfere with normal hormone function) in the fetus influences human health in later life.