Q&A: Side Effects of Oral Contrceptives

Since the development and approval of the first combined oral contraceptive (COC) pill, combined estrogen-progestin hormonal contraception (CHC) has evolved from high-dose estrogen formulations (150 mcg) to very low doses (10 and 20 mcg). Simultaneously, dosing mechanisms have expanded to include vaginal rings and the transdermal patch. While most women are candidates for CHC use and do well on them, the safety and side effect profiles must be considered as women balance their long-term need for birth control with the management and treatment of any concurrent medical conditions.

This article is for Medical Students & Professionals

This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Women's Health articles more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
Use in women with medical disorders
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

Use in women with medical disorders

While data are numerous regarding the safety of CHCs in healthy women, the smaller literature regarding CHC use in women with underlying medical conditions has been reviewed and summarized by the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC). Information is provided as documents discussing medical eligibility criteria (MEC; WHO MEC 5th Edition and US MEC 2016), a summary table (US MEC table), and as applications for handheld devices. These documents classify contraceptive method use into four categories of risk that consider the contraceptive method and underlying medical conditions of the patient

For most sexually active women of reproductive age, lack of contraception will eventually lead to pregnancy. Therefore, any negative side effects, health concerns, or health risks attributable to the CHC must be weighed against the risk of pregnancy for the individual woman. Decisions regarding contraception in women with chronic medical conditions are particularly crucial, as unintended pregnancy may pose substantial risk to both the woman and her fetus. Medical experts, therefore, rely on the MEC documents above, for use of CHC in the setting of medical conditions. One limitation is that much of the research, and therefore the medical guidance, is based on studies of estrogen-progestin oral contraceptive pills; there is far less research on the CHC transdermal patch and the ring.

MCQ exam: clinical scenario

A 40 year old mother of 3 has been using oral contraceptives since she was 35 years old. Her brother was recently diagnosed as having a tumour in his liver. She is worried about the risks of taking oral contraceptives.

Which of the following tumours is most likely to have an increased incidence after taking oral contraceptives?

a) Hepatic adenoma
b) Renal cell carcinoma
c) Ovarian carcinoma
d) Follicular carcinoma of the thyroid gland
e) Breast carcinoma

MCQ exam: answer

The correct answer is A.

MCQ exam: explanation

The risk of developing hepatic adenoma with oral contraceptives is 2.5 x risk after 5-year use, 7.5 x risk after 9-year use, 25 x risk >9-year use. Other aetiological factors of hepatic adenoma include steroids, pregnancy, diabetes mellitus, type Ia glycogen storage disease (von Gierke) in 60%.

Reference(s)
1). UpToDate: Combined estrogen-progestin contraception: Side effects and health concerns. Available online: https://www.uptodate.com/contents/combined-estrogen-progestin-contraception-side-effects-and-health-concerns