Diethylstilbestrol

In 1971, it was identified in a US study that DES could cause a distinct type of cancer in the daughters of women who took DES in early pregnancy. It was subsequently contraindicated in pregnancy, pre-menopausal women, children and young adults. The issue of DES and vaginal carcinoma in the daughters of women who took DES in pregnancy was reviewed by the predecessor to the Commission on Human Medicines, the Committee on Safety of Medicines (CSM) in the early 1970s. In 1973, the CSM wrote to all doctors to inform them of the results of the US study and the absence of cases identified in the UK.

Since 1992, the National Cancer Institute (NCI) at the US National Institutes of Health has been conducting the DES Follow-up Study of more than 21,000 mothers, daughters, and sons, exposed in the womb during the mother’s pregnancy, to better understand the long-term health effects of exposure to DES. The findings of this study have been published in the scientific literature.

As such, work has been undertaken to contact historic users of DES. Our sympathies are with anyone harmed by its historic use.

The UK Health Security Agency advises that routine cervical screening is appropriate for those who believe they were exposed to DES in utero. Further information is available at the following link:

https://www.gov.uk/government/publications/cervical-screening-programme-and-colposcopy-management/5-screening-and-management-of-immunosuppressed-individuals

Participation in the National Breast Screening Programme is also recommended. Pregnant women who know that they were exposed in utero to DES should inform their obstetrician and be aware of the increased risks of ectopic pregnancy and preterm labour.

The MHRA continuously assesses the benefit risk balance of all medicines at the time of initial licensing and throughout their use in clinical practice, carefully evaluating any emerging evidence on their benefits and risks.