From the Guidelines
Oral contraceptive pills (OCPs) can be used while flying, but it is essential to take precautions to minimize the risk of blood clots, especially during long flights over 4 hours. According to the American Society of Hematology 2018 guidelines 1, the risk of venous thromboembolism (VTE) is increased with air travel, and this risk is further elevated in individuals taking OCPs. The estimated absolute risk for symptomatic deep vein thrombosis (DVT) with air travel is approximately 0.05% (95% CI, 0.01-0.19) 1.
To minimize this risk, it is recommended to:
- Stay hydrated by drinking plenty of water
- Avoid alcohol and caffeine
- Walk around the cabin periodically
- Perform seated leg exercises
- Wear compression stockings if you have additional risk factors, such as a history of VTE or thrombophilia
- Consider taking an aisle seat for easier movement
These precautions are especially important for individuals with additional risk factors, such as smokers or those with a history of VTE, who take OCPs. The American College of Chest Physicians also notes that prolonged air travel results in a very small absolute incidence of VTE, but the risk is increased in the presence of VTE risk factors, such as recent surgery or estrogen use 1.
In terms of managing OCPs while flying, it is recommended to continue taking your birth control pills according to your regular schedule when traveling across time zones. If the time difference is less than 12 hours, take your pill at the same time according to your home time zone. For time differences greater than 12 hours, take your pill at the same clock time in your new location. Missing a pill during travel increases pregnancy risk, so consider setting an alarm as a reminder.
From the Research
OCP and Flying
- The use of Oral Contraceptive Pills (OCPs) in female aviation personnel has been studied to characterize continuous OCP use and perceived barriers to this practice, as well as to determine associations with menstrual burden 2.
- Continuous OCP users were found to be more compliant, reported less spotting and fewer unexpected menstrual cycles than conventional OCP users 2.
- A majority of women in the study desired menstrual suppression, yet only a small percentage reported using OCPs continuously 2.
- The study suggests that continuous OCP use in female aviation personnel is associated with improved compliance and reduced menstrual burdens, and that entry-level education may reduce barriers to continuous OCP use 2.
Venous Thromboembolism Prevention
- The prevention of venous thromboembolism (VTE) in surgical patients has been studied, with a focus on the use of low molecular weight heparin (LMWH) and graduated compression stockings 3, 4.
- The use of LMWH in combination with graduated compression stockings has been shown to result in a clinically significant decrease in VTE without inducing a significant increase in major bleeding 4.
- However, the use of LMWH versus aspirin for VTE prevention in orthopaedic trauma patients has been found to have no evidence of superiority between the two treatments 5.
Hormonal Contraceptives and VTE Risk
- The use of hormonal contraceptives, such as combined oral contraceptive pills, has been found to increase the risk of venous thrombosis 6.
- Estrogen-containing methods, such as combined oral contraceptive pills, increase the risk of venous thrombosis from 2 to 10 venous thrombotic events per 10,000 women-years to 7 to 10 venous thrombotic events per 10,000 women-years 6.
- Progestin-only and nonhormonal methods, such as implants and condoms, are associated with rare serious risks and do not increase the risk of VTE 6.