Diethylstilbestrol in Pregnancy: Canadian Medical Association Journal 1982 update

Use of DES in Canada, 1982

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DiEthylStilbestrol usage review buttress the need for adequate and rigorous research into the use of drugs in pregnancy and ensure that they do more good than harm before being introduced for consumption.


In November 1971 the health protection branch of the Department of National Health and Welfare announced, on the basis of data reported from the United States, an association of the use of diethylstilbestrol during pregnancy with the later development of adenocarcinoma of the vagina in exposed offspring.’ The health protection branch has since required the manufacturers of DES and other estrogenic drugs to include in their product literature a contraindication to the use of all estrogens during pregnancy. Similar warnings and reminders followed in subsequent issues of Rx Bulletin.

For the past decade the indications for the use of DES in Canada have been limited to the palliation of estrogen-responsive metastatic carcinoma of the breast and advanced carcinoma of the prostate.

In 1979 Canadian physicians were advised by the health protection branch’s special advisory committee on reproductive physiology, a group of nongovernment consultants, of the risks of congenital malformations and malignant disease in the offspring of women exposed to DES during pregnancy. While DES is no longer recommended for use during pregnancy, it is probably still being given for other purposes, such as postpartum suppression of lactation and postcoital contraception. These indications have not been approved by the health protection branch, and our committee does not recommend the use of DES for these purposes.

The problems associated with the use of DES during pregnancy concern both female and male offspring exposed in utero and the mothers themselves. While available evidence indicates that the magnitude of the DES problem in Canada is low we thought it advisable to summarize the current knowledge in this area for Canadian physicians.

Sources and more information
  • Diethylstilbestrol in pregnancy: an update, Canadian Medical Association Journal, 1982 Nov 1; 127(9): 812–813., NCBI PMID: PMC1862229.
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