Abnormal uterine bleeding control with combined oral contraceptives: a review comparing ethinylestradiol and natural hormones

Abstract Objective: To review the real benefits of using combined oral contraceptives (COCs) containing natural hormones, also known as estradiol-containing COC (estradiol and estradiol valerate) in controlling abnormal uterine bleeding (AUB) compared to the already established data on treatment with combined pills containing ethinylestradiol (EE). Methods: Narrative review with analysis of studies published between 2010 and 2023, comparing the effects of EE and natural estrogen in the treatment of AUB, indexed in the PUBMED, WebOfScience, and Scielo databases. Results: A total of 342 articles were found in the selected databases. Of these, 235 articles were excluded because they were published before 2010 or lacked an explicit relationship with the topic; 107 articles were selected for title and abstract screening, of which 27 were fully read by the researchers, and 6 were included in the study. It was observed that the use of natural estrogens is effective in controlling abnormal uterine bleeding, often with fewer side effects and less cardiovascular and prothrombotic impact compared to ethinylestradiol (EE). However, some non-contraceptive benefits of EE, such as less water retention, improved skin oiliness, and acne, were not consistently observed with the use of natural estrogens. Conclusion: Estradiol-containing COC have proven to be effective in controlling AUB, in addition to reducing spotting and intermenstrual bleeding, with fewer undesirable side effects when compared to COCs with EE. On the other hand, COCs with estradiol and estradiol valerate less frequently present other non-contraceptive benefits.