Secretary of State announcement: Harm inflicted on individuals exposed to Diethylstilbesterol (DES)

You may be aware that on 5 November 2025, the Secretary of State recognised the harm inflicted upon individuals who were exposed to Diethylstilbesterol (DES), including links to a rare and distinct type of cancer; reproductive tract abnormalities, and reduced fertility for daughters of women who took DES during pregnancy.

The Government has apologised for this.

DES was formerly used worldwide in the treatment of threatened miscarriage between the 1940s and 1970s. In 1971, an assessment of women in the U.S. with clear-cell adenocarcinoma of the vagina and cervix led to the first association between the development of this condition and prenatal exposure to DES. In the U.K., the issue was reviewed by the Committee on Safety of Medicines (CSM) and in 1973, the Committee took the decision to write to all doctors to inform them of the results of the U.S. study and the absence of identified cases in the U.K. The work of the CSM in the early 1970s predates the existence of the Medicines and Healthcare products Regulatory Agency (MHRA) when medicines vigilance was in its infancy.

There has been a step change in reporting and record keeping since this time and today’s regulatory frameworks are significantly different, with much stricter post-authorisation monitoring allowing for earlier identification and action on emerging safety issues. The MHRA regulates medicines supplied in the U.K. and its activity spans the whole of a medicine’s lifecycle. It also keeps the safety of all medicines under continual review. The Secretary of State has been clear the wider health system must now lead the way in supporting those impacted by these historic events.

NHS England has been asked to work with Cancer Alliances to make health professionals aware of the existing guidance which addresses individuals exposed to DES. I would be grateful if you could ensure the Secretary of State’s comments regarding DES and relevant guidance could be cascaded through your clinical networks to reach the appropriate professionals, including GPs and other health professionals who may come into contact with DES-exposed patients.

Particular attention should be drawn to guidance which advises women who believe or know that they were exposed to DES in utero and who may need colposcopy which falls outside of the routine screening programme. These women are advised to speak to their GP about this, as the guidance from NHS England sets out that local arrangements should be made for the follow up of women who have been exposed to DES. Further information is available via 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 NHS Breast Screening Programme is also strongly recommended for those who are aware that they were exposed to DES. Pregnant women who know that they were exposed to DES in utero should also inform their obstetrician or midwife, given that there is an increased risk of ectopic pregnancy and preterm labour.