COVID-19 May Increase Birth Control Pill Blood Clot Risks, Doctors Warn

Amid the on-going coronavirus pandemic, a new report warns about the potential for the risk of blood clots among patients taking hormone therapies, calling for further research to be conducted on the impact COVID-19 may have on birth control pills.

In an editorial published last week in the journal Endocrinology, Daniel Spratt, M.D., and Rachel J. Buchsbaum, M.D. indicate that venous thromboembolic events are common among patients infected with the coronavirus, potentially amplifying the risks of blood clots caused by other therapies that also carry known blood clot side effects.

Combined oral contraceptives carry a two- to six- fold increased risk for blood clots, according to the editorial. Similar risks are seen with oral hormone replacement therapy for women in menopause and oral estrogen therapy in male-to-female transgender patients. The risk of blood clot during pregnancy increases by four- to five-fold, the writers noted.

With this in mind, a large portion of the female population may be at further risk due to the COVID-19 epidemic, the authors warn, emphasizing the need to determine whether coronavirus exacerbates VTE and stroke risk already seen in at-risk populations.

“The emergence of this pandemic and the curious impact of this virus on hypercoagulability emphasize the continuing need for additional research into coagulation pathology in women,” wrote authors of the commentary.

While there has been no increased risk of VTE among pregnant women or women taking hormone therapy, a preliminary report indicated an increased incidence of placental vascular abnormalities among pregnant patients infected with COVID-19.

Overall, women consistently have fewer COVID-19 hospitalizations and deaths than men. Doctors are still unclear why.

Female sex hormones may be protective since estrogen can improve immune response to infection, the researchers noted. Furthermore, some research has hypothesized menstruation may also have beneficial effects against COVID-19.

Other research is examining the effects of giving estrogen to address the coronavirus, but those with a history of blood clots have been excluded. This fails to address the risk a history of VTE may play regarding COVID-19. More so, the majority of research focusing on COVID-19 and increased risk of blood clots is largely observational.

To that end, researchers emphasize the need to establish models for research into mechanisms of hypercoagulability in COVID-19. This will require both animal and human tissue models since coagulation is different in animals than humans.

Researchers must focus on whether the increased risk of blood clots in COVID-19 patients will affect pregnant women, placental health, or those undergoing estrogen therapy. If so, they need to determine what measures can be taken to reduce the risks among these patient populations.

“We do not know how long the current pandemic will endure and can be reasonably certain that, like the H1N1 virus causing the 1918-1919 influenza pandemic, SARS-CoV-2 will return cyclically for years if not decades,” Spratt and Buchsbaum wrote. “Thus, the importance of undertaking research to answer these questions will continue with findings likely to be applicable in a wide range of clinical situations.”