Selection, effectiveness and risks of contraception

Oral contraceptive pills are the most frequently used reversible contraceptives, but intrauterine devices and subcutaneous implants have the greatest effectiveness, according to a study published in the Journal of the American Medical Association.1

The review also concluded that risks are lowest in progestin-only and non-hormonal methods; however, the optimal selection of contraceptives must take into account patient values ​​and preferences.

The authors noted that approximately 87% of women in the United States use contraception in their lifetime, with oral contraceptive pills accounting for 21.9% of all current contraceptive use. But the use of long-acting methods like intrauterine devices and subdermal implants has increased dramatically over the years, from 6% in 2008 to 17.8% in 2016.

The effectiveness of contraception is determined by several factors, including the effectiveness of the drug or device, individual fecundability, frequency of coitus, and user compliance and continuation.

Pregnancy rates among those using oral contraceptives range from 4% to 7% per year, compared to failure rates of less than 1% per year for long-acting methods.

Regarding safety, estrogen-containing methods, such as combined oral contraceptive pills, increase the risk of venous thrombosis from 2 to 10 venous thrombotic events per 10,000 woman-years to 7 to 10 venous thrombotic events per 10,000 woman-years.

Due to concern over rising thrombosis rates, the authors believe that combined hormonal contraceptives are unlikely to be available over-the-counter (OTC), but efforts to allow over-the-counter progestin-only pills are progressing.

Meanwhile, progestin-only and non-hormonal methods, such as implants and condoms, are linked to rare and serious risks.

Hormonal contraceptives, the authors wrote, “may improve medical conditions associated with hormonal changes related to the menstrual cycle, such as acne, endometriosis, and premenstrual dysphoric disorder.”

Combination hormonal contraceptives also protect against endometrial and ovarian cancer; however, they have an increased risk of early diagnosis of breast cancer in current or recent users within the past 6 months, with an incidence of 68 cases per 100,000 person-years versus 55 cases per 100,000 non-user-years.

On the other hand, there is no association between prior contraceptive use and increased rates of cancer or mortality.

Although obesity has a negative impact on contraceptive steroid levels, it is unclear whether it affects contraceptive effectiveness, the authors say, noting that the main reason for contraceptive failure is poor adherence. suboptimal. They also pointed out that using any contraceptive method, regardless of weight, prevents more pregnancies than no method at all.

There is no high-quality evidence to support the recommendation of prior counseling to restrict the use of intrauterine devices by adolescents, non-monogamous or unmarried women, and nulliparous women. “None of these features are true contraindications,” the authors write.

Currently, the U.S. Food and Drug Administration lacks approved contraceptive options for men, except for condoms, according to the authors. Male contraceptive methods currently being evaluated attempt to reduce sperm count to

However, the best choice of contraceptive involves a discussion between the patient and the clinician about the patient’s tolerance for the risk of pregnancy, changes in menstrual bleeding, and other risks, as well as the patient’s personal values ​​and preferences. .

Patients may place more importance on certain characteristics of a method than on its effectiveness, such as route of administration or bleeding patterns, thus possibly promoting a slightly higher risk of unplanned pregnancy to avoid other side effects.

Reference

  1. Teal S, Edelman A. Contraceptive selection, effectiveness and adverse effects: a review. JAMA. Published online December 28, 2021. doi:10.1001/jama.2021.21392

Martin E. Berry