Interpreting Estrogen Lab Values in Women Taking Continuous Oral Contraceptives

Clinical Implications

• The Centers for Disease Control and Prevention, as reported in MMWR Recommendations and Reports, suggests assessing clinical symptoms such as breakthrough bleeding, vasomotor symptoms, and mood changes to evaluate hormonal adequacy in OCP users, rather than relying on laboratory values 1
• If inadequate estrogenic effect is suspected, consider switching to a different OCP formulation with higher ethinyl estradiol content, as recommended by MMWR Recommendations and Reports 1

Hormonal Effects

• OCPs increase sex hormone-binding globulin (SHBG) production, which binds and inactivates free testosterone and estradiol, complicating interpretation of sex hormone measurements, according to a study cited by the American College of Obstetricians and Gynecologists, although the specific details were found in 2