Key changes from the 2024 update to the US medical eligibility criteria for contraceptive use

The past few decades have seen significant growth in the number of contraceptive methods available on the US market, as well as a growth in the body of literature about how to provide contraceptive care safely and effectively. The more options and information we have, the more important it is for clinicians to have accessible, easy-to-use tools to guide our contraceptive counseling.

One of the most widely known tools is the US Medical Eligibility Criteria for Contraceptive Use (US MEC), which was first published by the CDC in 2010. Many providers may have decorated their office with one of the colorful US MEC summary charts cross-listing contraceptive methods and medical comorbidities or downloaded the smartphone application version for easy reference. The goal of the US MEC and its companion document, the US Selected Practice Recommendations for Contraceptive Use, was to adapt contraceptive use guidelines originally developed by the World Health Organization (WHO) into recommendations for US providers. For a given medical condition or patient factor, the US MEC stratifies the safety of each available contraceptive method into 4 categories (Table 1).

Since its first publication, the US MEC has undergone several revisions and updates. The most recent update, from 2024, is the first since 2016.¹ The updates were made after extensive review of studies from the Continuous Identification of Research Evidence database (jointly administered by the WHO and CDC) that were felt to have potential to change the previous recommendations. The CDC staff and other invited authors conducted systematic reviews for each of the potential revision topics being considered and then presented their findings at a CDC meeting held in January 2023. This meeting included experts in the field from a variety of health backgrounds, as well as patient perspectives and public comments on proposed revisions, which were solicited via the Federal Register. CDC staff then determined the final revisions based on feedback about the available evidence presented at the January meeting.¹ Although many changes were ultimately made, we will highlight the most significant here.

Injectable depot medroxyprogesterone acetate (DMPA) and thromboembolic risk

Due to new evidence, injectable depot medroxyprogesterone acetate (DMPA) should now be used with caution in patients at increased thromboembolic risk. Although the effects of estrogen-containing hormonal contraceptive methods on thromboembolic risk profile are long established, the evidence is mixed for progestin-only contraception (POC), such as DMPA.² The new recommendations are guided by a forthcoming systematic review and a 2020 systematic review and meta-analysis investigating the association between POC use and cardiometabolic outcomes.^3,4

In the systematic review from 2020, injectable POC showed an increased risk of venous thromboembolism (VTE) with an RR of 2.62 (95% CI, 1.74 -3.94) compared with nonusers of progestins.⁴ More recently, a matched case-control study in 2022 examined the risk of VTE among women of reproductive age who use various forms of POC.² Using an insurance claims database, the investigators reviewed 21,405 women with acute VTE and matched them 1:5 by birth year to a control group of 107,025 women without VTE. Compared with nonusers of progestins, they found an increased odd of VTE in DMPA users (aOR, 2.37; 99% CI, 1.95-2.88). Adjusted odds ratios for users of etonogestrel implants, levonorgestrel-releasing intrauterine devices (LNG-IUDs), or oral norethindrone did not indicate an increased risk of VTE. Given this evidence, DMPA has been changed from a category 1 or 2 method to a category 3 method for patients with certain conditions that may significantly increase their thromboembolic risk, as shown in Table 2.^1,3

DMPA has also been changed from a category 1 method to a category 2 method for patients with conditions that may mildly increase thromboembolic risk, such as postpartum patients and those with current or prior superficial venous thrombosis (known as valvular disease) or peripartum cardiomyopathy with less than moderate impairment of cardiac function.¹ In light of this new evidence, clinicians should consider a patient’s baseline thromboembolic risk before initiating or refilling DMPA prescriptions.

Sickle cell disease and thromboembolic risk

The next set of changes highlighted are those regarding recommendations for contraceptive use in patients with sickle cell disease. The new recommendations reflect increased evidence that sickle cell disease causes a prothrombotic state and that patients with sickle cell have increased risk of both arterial and venous thrombi.^5-7 In addition to elevated thromboembolic risk at baseline, they also have a significantly higher risk for thromboembolic events in pregnancy and the postpartum period.⁷ Evidence on thromboembolic risk for contraceptive users with sickle cell disease is limited, but available data do suggest a potential increase in thromboembolic risk for patients with sickle cell who use hormonal contraception specifically.

A 2023 study using population-level administrative claims assessed hormonal contraception use among patients with sickle cell disease and evaluated the risk of thromboembolism during the first year after initial contraceptive prescription.⁸ They evaluated 7143 patients with a new prescription for hormonal contraception and a diagnosis of sickle cell disease, 44.6% of whom received combined hormonal contraception (CHC) and 55.4% of whom received POC. Of these patients, 126 (1.8%) had a thromboembolic event within the first year of use of their hormonal contraception.⁸ The thromboembolic event rate in patients with sickle cell disease during the first year of hormonal contraceptive use was 21 events per 1000 person-years. Combined oral contraceptives have been associated with an increased risk of VTE in the general population, with an absolute risk of 0.1 to 0.3 events per 1000 person-years.⁹ This study suggests that there may be a higher risk of thromboembolic events in new users of hormonal contraception who have sickle cell disease compared with the general population of hormonal contraception users.

The 2024 US MEC recommendations have been updated to reflect the known increased thromboembolic risk in the sickle cell population and the newer evidence presented above. CHC of all varieties, including pills, patches, and rings, are now category 4.^1,3 DMPA is now considered category 2 or 3, as mentioned above; the determination of category 2 vs 3 depends on the severity of a patient’s sickle cell disease and other factors that may affect thromboembolic risk.⁸

In any discussion of contraception for patients with sickle cell, the significant morbidity and mortality risks associated with pregnancy itself should also be acknowledged. In addition to increased risk of sickle-related complications, such as acute coronary syndrome, pneumonia, and thromboembolic events during pregnancy, patients with sickle cell disease experience higher rates of poor obstetric outcomes, including fetal growth restriction, preterm birth, and intrauterine fetal demise.¹⁰ This unique risk-benefit calculus can significantly complicate the choice of contraceptive methods for patients with sickle cell, and it underscores the importance of a shared decision-making approach to optimize their reproductive health.

Addition of chronic kidney disease

The most recent update to the US MEC also includes the addition of a new medical condition that was not previously listed on its own: chronic kidney disease (CKD). CKD is further broken down into subcategories based on the presence or absence of nephrotic syndrome and whether the patient requires hemodialysis or peritoneal dialysis.^1,3 The data on contraceptive users with CKD are limited, though the CDC’s expert working group plans to publish a forthcoming systematic review on this topic in Contraception.³ Therefore, the updated recommendations reflect a risk of worsening kidney disease, hypertension, thrombosis, adverse events, or reduced contraceptive effectiveness among those who have CKD and use hormonal contraception.

For this reason, CHC of all types is considered category 4 and DMPA is considered category 3 for patients with CKD who have nephrotic syndrome or are on either type of dialysis. The etonogestrel implant and all doses of LNG-IUDs are considered category 2 for these patients. The copper IUD is considered category 1, though initiation of a new copper IUD for a patient on peritoneal dialysis specifically is considered category 2 due to a very small number of case reports of patients who experienced peritonitis or peritoneal allergic reactions after insertion.³ All listed barrier methods are considered category 1. The eligibility criteria for progestin-only pills (POPs) depend on the specific progestin in question. Because drospirenone-containing POPs can increase serum potassium levels, drospirenone POPs are considered category 4 for patients with CKD with known hyperkalemia, though other POPs are considered category 2. For patients with CKD without known hyperkalemia, drospirenone POPs are considered category 2, though the US MEC does recommend checking a serum potassium level during the first cycle of drospirenone POP use.¹

Reductions in risk level and other changes

Although the changes we have highlighted so far all reflect a heightened concern about the safety of specific contraceptive methods in particular populations, there were also revisions that reflected decreased safety concerns. For example, all POC methods except for DMPA (eg, LNG-IUDs, etonogestrel implants, and POPs) have changed from category 3 to category 2 for patients with the conditions listed in Table 3. Several other changes also reflect increased safety of contraceptive methods for certain medical conditions. Please see Table 4 for a summary of these changes.^1,3

Additionally, new contraceptive methods have been added, including new formulations of CHC (eg, patches and vaginal rings), new formulations of POPs, new doses for LNG-IUDs, and the vaginal pH modulator (Phexxi).¹ The document has also been edited to use gender-inclusive language, and there is an increased emphasis on contraceptive autonomy, patient-centered counseling, and shared decision-making.

Conclusions

The US MEC should always be considered a set of “tools, not rules.” Based on the updates and evidence described above, clinicians should consider a patient’s baseline thromboembolic risk when providing contraception, particularly for prescription of DMPA or for patients with sickle cell disease or CKD. However, these new recommendations should be utilized within the context of a shared decision-making approach that incorporates the patient’s goals, preferences, and likelihood of pregnancy. The health risks of pregnancy should also be considered and discussed when discussing the health risks of contraceptive methods. This is especially true for patients with sickle cell disease or CKD who may be at increased risk of pregnancy-related morbidity and mortality, making the prevention of undesired pregnancy even more important. Ultimately, the decision of whether and how to contracept can be affected by a multitude of factors spanning patients’ medical history, lifestyle, past experiences, future fertility desires, and more. The best contraceptive method for any patient who desires pregnancy prevention is the one they will use consistently and correctly.

References

1. Nguyen AT, Curtis KM, Tepper NK, et al. U.S. Medical Eligibility Criteria for Contraceptive Use, 2024. MMWR Recomm Rep. 2024;73(4):1-126. doi:10.15585/mmwr.rr7304a1

2. Cockrum RH, Soo J, Ham SA, Cohen KS, Snow SG. Association of progestogens and venous thromboembolism among women of reproductive age. Obstet Gynecol. 2022;140(3):477-487. doi:10.1097/AOG.0000000000004896

3. Appendix A: summary of classifications for U.S. Medical Eligibility Criteria for Contraceptive Use, 2024. CDC. November 19, 2024. Accessed November 30, 2024. https://www.cdc.gov/contraception/hcp/usspr/classifications-mec-contraception.html

4. Glisic M, Shahzad S, Tsoli S, et al. Association between progestin-only contraceptive use and cardiometabolic outcomes: a systematic review and meta-analysis. Eur J Prev Cardiol. 2018;25(10):1042-1052. doi:10.1177/2047487318774847

5. Brunson A, Keegan T, Mahajan A, White R, Wun T. High incidence of venous thromboembolism recurrence in patients with sickle cell disease. Am J Hematol. 2019;94(8):862-870. doi:10.1002/ajh.25508

6. Naik RP, Streiff MB, Haywood C Jr, Segal JB, Lanzkron S. Venous thromboembolism incidence in the Cooperative Study of Sickle Cell Disease. J Thromb Haemost. 2014;12(12):2010-2016. doi:10.1111/jth.12744

7. Noubiap JJ, Temgoua MN, Tankeu R, Tochie JN, Wonkam A, Bigna JJ. Sickle cell disease, sickle trait and the risk for venous thromboembolism: a systematic review and meta-analysis. Thromb J. 2018;16:27. doi:10.1186/s12959-018-0179-z

8. Bala NS, Stanek JR, Vesely SK, et al. Comparison of thromboembolism outcomes in patients with sickle cell disease prescribed hormonal contraception. Blood Adv. 2023;7(20):6140-6150. doi:10.1182/bloodadvances.2023010204

9. Gialeraki A, Valsami S, Pittaras T, Panayiotakopoulos G, Politou M. Oral contraceptives and HRT risk of thrombosis. Clin Appl Thromb Hemost. 2018;24(2):217-225. doi:10.1177/1076029616683802

10. Society for Maternal-Fetal Medicine, Sinkey RG, Ogunsile FJ, et al. Society for Maternal-Fetal Medicine Consult Series #68: sickle cell disease in pregnancy. Am J Obstet Gynecol. 2024;230(2):B17-B40. doi:10.1016/j.ajog.2023.10.031