Cardiovascular Disease and Steroid Hormone Contraceptives

Steroid hormone contraceptives have been available since the 1960s and are now used by more than 100 million women worldwide. Reports linking combined oral contraceptives with cardiovascular side-effects (venous and arterial thrombotic events) appeared soon after these products were first marketed. Since then a large number of epidemiological studies have investigated whether users of combined oral contraceptives are at increased risk of cardiovascular disease. Information is now available about the effects of more recently introduced combined oral contraceptives from several large, recently completed studies, including the WHO Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception (which was conducted in 21 centres in different countries in Africa, Asia, Europe and Latin America).

On 3–7 November 1997, the Programme convened in Geneva a Scientific Group Meeting on Cardiovascular Disease and Steroid Hormone Contraception. The overall objective of the Scientific Group was to review current scientific data on the use of steroid hormone contraception as they relate to risk of myocardial infarction, ischaemic and haemorrhagic stroke, and venous thromboembolic disease.

In its discussions the Scientific Group relied mainly on published data, although it also considered unpublished information from several new studies. Acknowledging the major changes that have taken place in the hormonal content of combined oral contraceptives and prescribing patterns, the Scientific Group paid particular attention to studies which included data collected after 1980.

The Scientific Group concluded that the incidence and mortality rates of all cardiovascular diseases (stroke, myocardial infarction, and venous thromboembolism) in women of reproductive age are very low. Any additional cardiovascular disease incidence or mortality attributable to oral contraceptives is very small if the users do not smoke and do not have other cardiovascular risk factors. This issue of Progress summarizes the discussions of the Scientific Group. For easy reference, the conclusions of the Scientific Group are reproduced with regard to each disease, as are the Group's final recommendations regarding future areas of research.

Although the focus of the Scientific Group deliberations was on the cardiovascular effects of steroid contraceptives, other considerations also influence women and couples when they make their choice of contraceptive method. These factors include real and perceived risks and benefits associated with each method of contraception. Social, economic, psychological and cultural factors are also important. The conclusions and recommendations of the Scientific Group should not, therefore, be taken in isolation. Instead, they should form part of the detailed information needed when making informed choices in this important area of preventive health care. The background papers prepared for the meeting have been published in the journal Contraception (volume 57, March 1998). The final report of the Scientific Group Meeting has been published by WHO.*

*Cardiovascular disease and steroid hormone contraception. Report of a Scientific Group. Geneva, World Health Organization, 1998 (WHO Technical Report Series, No. 877).

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