The decision to use or discontinue combined oral contraceptives (COCs) is a very personal one, as we’ve discussed already. Particularly for women who do not have any ethical or religious conflicts with contraception, an emphasis must be placed on weighing the benefits against the risks for a given set of circumstances. The purpose of this mini-series is to provide scientifically grounded information to women seeking to better understand the health risks associated with oral contraceptive use in order to make informed personal health decisions – it’s not about making judgments or defining right and wrong. Only you can determine the best course of action for you, given your particular circumstances and future reproductive intentions.
Left Hemisphere Stroke, via Google Images
http://www.theuniversityhospital.com/stroke/inhospital.htm
http://www.theuniversityhospital.com/stroke/inhospital.htm
The Pill & Vascular Health
The risk of “blood clots” seems to be the most widely recognized of the many COC-related health risks, so we’ll start there (though you’re probably already inferring from my use of quotation marks that there’s a lot more to the story). Blood clots (also known as thromboses) are serious business, as they can break free (or embolize) and travel to any number of vital organs, blocking blood flow and causing ischemia (inadequate blood supply resulting in prolonged oxygen shortage and tissue death). When this happens in the brain, we call it a stroke. When it happens in the heart, we call it a heart attack. We all know that stroke and heart attack are life-threatening and life-altering events. But ischemic events can cause damage to the liver, lungs, eyes, kidneys… any organ that receives blood flow (and if you have a pulse, that should include ALL of them!).
Deep vein thromboses (DVT), or blood clots of the deep veins (usually in the legs) can also form in the extremities and cause pain and swelling, and are often the culprit underlying pulmonary embolism (PE). Blood from the lower extremities returns directly to the right side of the heart and is immediately pumped out to the lungs to pick up fresh oxygen, at which point the oxygenated blood returns to the left side of the heart to be pumped out to the rest of the body. The arrangement of this circuit provides a convenient, direct pathway through which an existing DVT can send a chunk of clot up to the lungs where it lodges and forms a PE. The presence of a PE prevents blood from reaching certain areas of the lung by blocking blood vessels, creating “dead space” in the lung where no blood is arriving to pick up the fresh oxygen, which means that less oxygen is transferred from the lung to the blood with each breath. This oxygenation difficulty can quickly lead to labored breathing, rapid heart rate, cardiac arrhythmia and sudden death.
Deep vein thromboses (DVT), or blood clots of the deep veins (usually in the legs) can also form in the extremities and cause pain and swelling, and are often the culprit underlying pulmonary embolism (PE). Blood from the lower extremities returns directly to the right side of the heart and is immediately pumped out to the lungs to pick up fresh oxygen, at which point the oxygenated blood returns to the left side of the heart to be pumped out to the rest of the body. The arrangement of this circuit provides a convenient, direct pathway through which an existing DVT can send a chunk of clot up to the lungs where it lodges and forms a PE. The presence of a PE prevents blood from reaching certain areas of the lung by blocking blood vessels, creating “dead space” in the lung where no blood is arriving to pick up the fresh oxygen, which means that less oxygen is transferred from the lung to the blood with each breath. This oxygenation difficulty can quickly lead to labored breathing, rapid heart rate, cardiac arrhythmia and sudden death.
The causal relationship between COCs and these vascular health risks is complex. Oral contraceptives essentially mimic pregnancy by providing the balance of hormones that a pregnant woman’s body would produce, which leads to cessation of the normal cyclical hormone fluctuations that cause ovulation and menstruation. (The “menstruation” that women experience on the Pill really isn’t true menstruation, but rather “withdrawal bleeding” that is triggered by the withdrawal of progesterone during the “sugar pill” [or very low-dose] week of the Pill pack.) This particular balance of hormones is known to produce elevated levels of various clotting factors in the blood and to increase platelet aggregation both in the pregnant state and (to a slightly lesser degree) during COC use4. There are also studies that have implicated COC use in the genesis of hypertension1,2 (known more commonly as chronic high blood pressure), and still others that have demonstrated elevated serum cholesterol levels in COC users relative to non-users2 – factors that have yet to be causally linked to COC-related thrombosis and heart attack, but that certainly may play a role.
And now for the nuts and bolts3,5:
- The risk of venous thrombosis increases 3 to 6-fold in oral contraceptive users relative to non-users.
- That risk is doubled again for the “third generation” (read: newest) combined oral contraceptives containing desogestrel or gestodene.
- Stroke and heart attack risk is elevated 2 to 5-fold relative to non-users.
- Risk does increase with age, as well as risk factors such as high cholesterol, high blood pressure, diabetes and smoking.
- What about “low-dose” pills? Are they safer? Unfortunately, most studies say no – these risk statistics hold for the newer low-dose pills as well (though there are a few studies that report a modest decrease in heart attack risk).
- What if I only used the Pill for a year or two? These risks are independent of the duration of use, so whether you used the Pill for a few months or a decade, your risk is the same.
Most young women on the Pill stand a good chance of never experiencing any of these health issues, especially if they don’t smoke and live out an overall healthy lifestyle. What is disturbing is that rather than put this information out there so that women can make their own informed decisions, many practitioners choose to disregard the information altogether. They have decided on their own that the benefits outweigh the risks, and so the decision has been made for the patient, and without the patient’s knowledge. Many women don’t even realize that there are serious potential consequences to be weighed. I hope that this knowledge will empower you to take a second look at your reproductive health and make an informed, conscious decision.
Stay tuned for further exploration of the health risks associated with oral contraceptive use. I plan to tackle cancer, bone loss, infertility, and permanent loss of libido among many other intriguing topics in women’s health.
***UPDATE: Catch the next post in this series, Contraindications to COC Use
References
1. Basile, J. and M. Bloch. Identifying and managing factors that interfere with or worsen blood pressure control. Postgraduate Medicine. 2010 Mar; 122(2):35-48.
References
1. Basile, J. and M. Bloch. Identifying and managing factors that interfere with or worsen blood pressure control. Postgraduate Medicine. 2010 Mar; 122(2):35-48.
2. Bressler, R. and J. Durand. Oral contraceptive risks: a realistic appraisal. Drug Therapy. 1979 Oct; 9(10):81-95.
3. Martinez, F. and A. Avecilla. Combined hormonal contraception and venous thromboembolism. European Journal of Contraception & Reproductive Health Care. 2007 Jun; 12(2):97-106.
4. Poller, L. Relation between oral contraceptive hormones and blood clotting. Journal of Clinical Pathology. 1969; 3: 67–74.
5. Tanis, B. and F. Rosendaal. Venous and arterial thrombosis during oral contraceptive use: risks and risk factors. Seminars in Vascular Medicine. 2003 Feb; 3(1):69-84.
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