Some Birth Control Pills Have Slightly Higher Risk Of Venous Thromboembolism

MedicalResearch.com Interview with:
Yana Vinogradova, Research Fellow
Division of Primary Care
School of Medicine
University of Nottingham

Medical Research: What is the background for this study? What are the main findings?

Response: Combined oral contraceptives are an effective method of birth control but do have measurable side effects.  One – common to all combined contraceptives and sometimes fatal – is an increased risk of venous thromboembolism (VTE).  A number of earlier studies investigated VTE risks for different types of hormonal contraceptives, but all were performed some years ago or had insufficient data to analyse newer preparations, while some included only healthy users and others did not adequately control for lifestyle and health issues.  The data used for this study were representative of the UK population and covered all currently prescribed drugs, with results adjusted for the widest possible range of available relevant factors.

We found that the venous thromboembolism risks of combined oral contraceptives appear to fall into two distinct groups.  Newer drugs containing gestodene, desogestrel, drospirenone or cyproterone were associated with risks of VTE between 1.5 and 1.8 times higher than both the older compositions containing norethisterone or levonorgestrel and the relatively newer norgestimate.  While our findings are statistical associations between different compositions and venous thromboembolism risks, they do represent more comprehensive and reliable information for doctors making evidence-based prescribing decisions. Continue reading

Long Term Influence of Oral Contraceptives on Mortality

MedicalResearch.com Interview with:
Karin B. Michels, ScD, PhD
Associate Professor of Obstetrics, Gynecology and Reproductive Biology
Harvard Medical School

Medical Research: What is the background for this study? What are the main findings?

Dr. Michels: We were interested in studying the long-term effects of oral contraceptive use on mortality. Given the widespread use of oral contraceptives, this is an important question pertaining to millions of women worldwide.  We explored this question in the large Nurses’ Health Study, a cohort of 121,700 women in the US, who have been followed for 38 years. We found that oral contraceptive use does not impact overall mortality. However, breast cancer mortality was slightly increased, especially with long-term use of oral contraceptives.
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