Oral contraceptive pills (OCPs), and other estrogen-containing contraceptives (e.g., ring and patch), are an excellent choice for some women and have many health benefits. Besides being highly effective contraception, they can decrease dysmenorrhea, menorrhagia, acne, hirsutism, anemia, and endometriosis pain. They are also used to treat polycystic ovarian syndrome (PCOS) and are associated with decreased risk of ovarian and endometrial cancers.
Most providers are familiar with possible side effects of OCPs such as breakthrough bleeding, breast tenderness, nausea, and headache, and counsel patients accordingly. Providers also counsel every patient about the unlikely but serious adverse effect of venous thromboembolism using the ACHES mnemonic (abdominal pain, chest pain, headache, eye problem, severe leg pain), even though the incidence is only one in 1000.
Many providers don’t know to counsel about a much more frequent adverse effect that happens to one in five users: sexual dysfunction. Estrogen-containing contraceptive use can affect all areas of sexual functioning (desire, arousal, orgasm, pain) and is an important issue to discuss both prior to starting and at surveillance visits.
Symptoms can vary widely in terms of onset, severity, and specificity. Providers often don’t consider hormonal causes when evaluating a patient’s complaints if the patient is not in a group where hormonal changes are apparent, such as being postpartum or perimenopausal. The physiologic basis for the sexual dysfunction is the same in all these scenarios: decreased hormonal stimulation of the vulva and vagina leading to atrophic changes.
It’s understandable to think that taking a pill (or using a ring or patch) containing hormones would increase the amount of those hormones in the body—but that’s not what happens. The hormones that come from the contraceptives tell the ovaries to shut down, so they stop ovulating (which is the mechanism preventing conception), and they also stop producing their hormones. So now, the estrogen and progesterone in the body are only coming from the contraceptive, which are much smaller amounts than what the ovaries were making. This issue is even more of a problem with low-dose pills.
Other mechanisms affect hormone levels as well. Estrogen-containing contraceptives increase the amount of sex-hormone binding-globulin (SHBG) produced by the liver. SHBG binds to free estrogens and testosterone in the blood, making them unavailable. The hormones are not active until they are freed from SHBG and can enter cells to activate their receptors. Estrogen and androgen receptors in the vagina and vulva are shut down when the ovaries stop producing hormones, so even if hormones can get into the cell, the receptors can’t be activated. Decreased estrogen leads to atrophic vaginitis.
Testosterone binds the most tightly to SHBG. Testosterone is thought to be primarily a male hormone, but the small quantities women produce are critical to sexual functioning. Decreased testosterone can impair desire, arousal, and orgasm, and can cause vulvar pain, specifically in the vestibule, the area of the vulva just outside the opening to the vagina. It goes from just below the clitoris to the fourchette, and from side-to-side, its borders are where the inside of the labia minora change color and texture (known as Hart’s line). The vestibule includes the opening to the urethra, Skene’s ducts, and Bartholin’s glands. The vestibule is significant because it comes from a different embryological germ layer than the vagina and has more androgen receptors than estrogen receptors; therefore, it is more sensitive than the vagina to decreased testosterone levels. Without testosterone, the vestibular tissue thins, becomes painful, and is more likely to tear; lubrication also decreases.
Sexual side effects can vary based on the type of contraceptive. All OCPs have the same estrogen component (Ethinyl estradiol) in different amounts. Progestins (synthetic progesterone) vary widely between contraceptives, and some are more androgenic than others. “Androgenic” refers to how closely the progestin molecule resembles the testosterone molecule. The more similar the molecule, the more similar the effects—so pills with higher androgenic activity are less likely to cause sexual dysfunction. One progestin, drospirenone, is an anti-androgen and has the greatest risk of sexual side effects.
Other factors that determine why some are affected and others are not include genetic variations in both the quantity and sensitivity of androgen receptors and variations in hormone production. Someone with many androgen receptors and higher testosterone levels may be able to tolerate increased SHBG levels without sexual side effects, while someone with fewer receptors and lower testosterone may be symptomatic.
Sexual dysfunction, particularly pain, affects patients on many levels. It can start as a physical problem but often leads to anxiety, depression, relationship stress, and self-esteem issues. These stressors can lead to increased physical pain and stress through both hormonal and neurological pathways. Stopping this sexual pain cycle and addressing all the factors holistically is critical.
Midwives are uniquely qualified to address these issues. The relationships we forge with our patients often grant us the privilege of being the first or only providers our patients confide in about such intimate topics. We are experts at listening and supporting, and we have the clinical knowledge to diagnose and treat many of the factors affecting sexual functioning. For those issues outside of our scope or comfort level, strong relationships with other providers we collaborate with are essential.
So, what can you do to help these patients? Include sexual dysfunction as part of your counseling about possible side effects of OCPs and other estrogen-containing contraceptives. Consider this etiology as part of your differential diagnoses when evaluating a patient with sexual dysfunction. Finally, watch my presentation during the upcoming ACNM 66th Annual Meeting entitled, “Oral Contraceptive Pills and Sexual Dysfunction.” We will dive deeper into anatomy and physiology, hormones, risk factors, and history-taking. We will also cover physical examination, laboratory tests, medications, treatments, and complementary therapies. You will leave with a renewed confidence in your ability to address this issue with your patients.