gynecology and obstetrics
Oral Contraceptives
Adverse Effects of Oral Contraceptives
Although oral contraceptives may have some adverse effects, the overall risk of these effects is small. Bloating, breast tenderness, nausea, and headache are the most common adverse effects. Patients on combined OCs may develop amenorrhea or breakthrough bleeding (bleeding while taking the active pills) with prolonged duration of use. Either of these effects may be managed by changing to a pill with a higherestrogendose. Progestin-only pills often cause irregular vaginal bleeding. In some women, ovulation remains inhibited for a few months after they stop taking OCs, but there is no long-term effect on fertility. OCs do not adversely affect the outcome of pregnancy when conception occurs during or after their use. Estrogens increase aldosterone production and cause sodium retention, which can cause dose-related, reversible increases in blood pressure (BP) and in weight (up to about 2 kg). Weight gain may be accompanied by bloating and edema. Mostprogestinsused in OCs are related to 19-nortestosterone and are androgenic. Norgestimate,etonogestrel, and desogestrel are less androgenic thanlevonorgestrel,norethindrone,norethindroneacetate, and ethynodiol diacetate. Androgenic effects may include acne, nervousness, and an anabolic effect resulting in weight gain. If a woman gains>4.5 kg/year, a less androgenic OC should be used. Newer 4th-generation antiandrogenicprogestinsinclude dienogest anddrospirenone(related tospironolactone, a diuretic). Deep Venous Thrombosis (DVT) None Breast Cancer None Cervical Cancer None Ischemic Stroke None Althoughprogestinsmay cause reversible, dose-relatedinsulinresistance, use of OCs with a lowprogestindose rarely results in hyperglycemia. Serum high-density lipoprotein (HDL) cholesterol levels may decrease when OCs with a highprogestindose are used but usually increase when OCs with lowprogestinandestrogendoses are used. Theestrogenin OCs increases triglyceride levels and can exacerbate preexisting hypertriglyceridemia. Most alterations in serum levels of other metabolites are not clinically significant. Thyroxine-binding globulin capacity may increase in OC users; however, free thyroxine levels, thyroid-stimulating hormone levels, and thyroid function are not affected. Levels ofpyridoxine, folate, B complex vitamins,ascorbic acid, calcium,manganese, and zinc decrease in OC users;vitamin Alevels increase. None of these effects is clinically significant, and vitamin supplementation is not advised as an adjunct to OC use. Primary Biliary Cholangitis (PBC) None Risk of developinggallstonesdoes not appear to be increased by use of low-dose OCs. Hepatocellular Adenoma None Drug Interactions None 1.Fitzpatrick D, Pirie K, Reeves G, et al: Combined and progestagen-only hormonal contraceptives and breast cancer risk: A UK nested case-control study and meta-analysis.PLoS Med20(3):e1004188, 2023. Published 2023 Mar 21. doi:10.1371/journal.pmed.1004188 2.ACOG Practice Advisory: Hormonal contraception and risk of breast cancer. American College of Obstetricians and Gynecologists. Published 2018, reaffirmed 2022. 3.Iversen L, Sivasubramaniam S, Lee AJ, et al: Lifetime cancer risk and combined oral contraceptives: the Royal College of General Practitioners' Oral Contraception Study.Am J Obstet Gynecol216(6):580.e1-580.e9, 2017. doi:10.1016/j.ajog.2017.02.002 