Can progesterone-only birth control (Progestin-only contraceptive) provoke pulmonary embolism (PE)?

From the Guidelines

Progesterone-only birth control methods are a lower-risk option for provoking pulmonary embolism (PE) compared to combined hormonal contraceptives, but the risk is not entirely eliminated, especially with certain types like injectable DMPA. When considering the risk of PE with progesterone-only birth control, it's essential to differentiate between the various types of progesterone-only methods. According to the 2020 American College of Rheumatology guideline for the management of reproductive health in rheumatic and musculoskeletal diseases 1, the risk of venous thromboembolism (VTE) in healthy women taking progestin-only contraception is debated, but progestin-only methods are widely accepted as a lower-risk option in patients for whom estrogens are contraindicated.

Some key points to consider:

• The progestin-only pill and the progestin IUD are not associated with an increased risk of VTE, with relative risks (RRs) of 0.90 (95% confidence interval [95% CI] 0.57–1.45) and 0.61 (95% CI 0.24–1.53), respectively 1.
• Injectable DMPA, however, may impart a higher VTE risk than other progestin-only contraceptives, similar to that with oral estrogen-progestin contraceptives, with an RR of 2.67 (95% CI 1.29–5.53) 1.
• The copper IUD is a highly effective alternative that does not increase the risk of VTE but may increase menstrual bleeding and cramping for several months after insertion 1.
• Progestin IUDs, such as those containing levonorgestrel, may decrease menstrual symptoms and are a recommended option for patients with positive antiphospholipid antibodies (aPL) 1.

In the context of real-life clinical medicine, it is crucial to weigh the benefits and risks of each progesterone-only method and consider individual patient factors, such as a history of blood clots or clotting disorders, when selecting a contraceptive option. Women with a history of PE or other risk factors should discuss their contraceptive options with their healthcare provider to determine the safest choice. Any unexplained shortness of breath, chest pain, or swelling/pain in the legs while using any hormonal contraceptive should prompt immediate medical attention.

From the Research

Progesterone Only Birth Control and Pulmonary Embolism

• The relationship between progesterone-only birth control and pulmonary embolism (PE) is not directly addressed in the provided studies, but the risk of venous thromboembolism (VTE), which includes PE, is discussed in several studies 2, 3, 4, 5.
• According to a study published in 2019, progestin-only hormonal contraception is not associated with a significant increase in the risk of VTE, with the exception of depot medroxyprogesterone acetate 2.
• A systematic review published in 2016 found that the majority of evidence did not suggest an increase in odds for venous or arterial events with the use of most progestin-only contraceptives, including progestin-only pills, implants, and levonorgestrel-releasing intrauterine devices 4.
• However, the same review found that limited evidence suggested increased odds of VTE with the use of injectables, such as depot medroxyprogesterone acetate, and progestin-only contraceptives used for therapeutic indications 4.
• Another study published in 2012 found that progestin-only contraception was not associated with an increased risk of VTE, except for depot medroxyprogesterone acetate, which was associated with an increased risk of VTE in certain populations, such as smokers and women with thrombogenic mutations 3.

Comparison with Other Contraceptives

• A study published in 2012 compared the risk of VTE associated with different types of combined hormonal contraceptives and found that those containing levonorgestrel or norgestimate were associated with a lower risk of VTE compared to those containing other progestogens, such as desogestrel, drospirenone, or cyproterone acetate 5.
• A systematic review published in 2022 found that micronized progesterone, a type of progestin-only contraceptive, was not associated with an increased risk of VTE or arterial thromboembolism when used in combination with estrogen therapy 6.

Overall Risk

• While the provided studies do not directly address the risk of PE associated with progesterone-only birth control, they suggest that the risk of VTE, which includes PE, is generally low with most progestin-only contraceptives, except for depot medroxyprogesterone acetate and certain therapeutic indications 2, 3, 4.