Oral Contraceptives and Smoking — What Are the Health Risks?

Oral Contraceptives and Smoking — What Are the Health Risks?
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How the Pill Effects the Body

Oral contraceptives are pills that women take to prevent pregnancy. They supply a specific combination of synthetic female hormones, estrogen and progestin, to control the female reproductive system so that pregnancy will not occur. The dose of hormones causes several changes — eggs are not released from the ovaries, the lining of the uterus changes so a fertilized egg cannot develop and the cervix changes to stop male sperm from entering.

While these hormone pills are very effective for preventing pregnancy, they do come with a long list of potential side effects. Some are minor, such as constipation, acne, and vaginal discharge. Others are more of a health concern, such as an increased risk for liver tumors, for developing breast or liver cancer, and for heart attack, strokes, and blood clots. The possibility of developing a dangerous blood clot is even more of a concern for women who smoke and are on the pill. How serious is the risk of developing blood clots when using oral contraceptives and smoking?

Estrogen, Blood Clots, and Smoking

How do oral contraceptives affect cardiovascular health? Why are blood clots more likely for women who take the pill? Why are women who smoke at a greater risk? The hormone estrogen causes blood to coagulate, making clots possible. It also raises blood pressure and affects lipids, leading to weight gain. Because of this, over the years of the existence and usage of oral contraceptives the dosages of estrogen and progestin have been altered to try and decrease these negative effects on cardiovascular health. There is even a hormone pill that contains no estrogen, known as the progestin-only pill, or POP. It is important to note that the more recently developed oral contraceptives known as third generation pills, which contain estrogen and different forms of progestin than their predecessors, appear to pose a greater risk of developing blood clots.

If a blood clot forms from taking birth control pills it develops in the veins of the leg. The clot can cause a blockage in the leg or, in rare cases, travel to the lungs. In very rare cases (about 3%) a woman can die if she develops a blood clot. While the chances of blood clots forming from taking oral contraceptives is low enough for the pill to still be considered safe, the danger increases for women who smoke. Smoking increases blood pressure and increases the tendency for blood to clot. Smoking and taking oral contraceptives significantly increases a women’s risk of developing heart disease and of having a stroke.

Managing Your Health While Taking Oral Contraceptives

Is it safe to smoke cigarettes if you are taking birth control pills? The chances are very low that a blood clot will form and cause harm, but at the same time the chances are very real. Smoking less cigarettes decreases the risk. Choosing a contraceptive pill that does not contain estrogen is another way to manage risk. Other factors that increase your risk for heart disease and stroke, such as being overweight, high blood pressure, stress, a poor diet, and high cholesterol should be considered as well. Being aware of the potential danger of taking oral contraceptives and smoking is so important for women to make informed lifestyle choices regarding their health. Talk to your doctor about your, health, risk, and options and do not underestimate the importance of making choices for well-being.


WebMD https://www.webmd.com/sex/birth-control/birth-control-pills

Medicine Plus https://www.nlm.nih.gov/medlineplus/druginfo/meds/a601050.html

New York Times https://www.nytimes.com/2007/02/13/health/13cons.html

MedSafe https://www.medsafe.govt.nz/consumers/leaflets/oralcontraceptives.asp

Family Health International https://www.fhi.org/en/RH/Pubs/Network/v16\_2/nt16212.htm

American Heart Association https://www.fhi.org/en/RH/Pubs/Network/v16\_2/nt16212.htm

photo by Allessandro Bovini