Female astronauts who want to manipulate or stop menstrual bleeding during their time in space have sometimes turned to oral contraceptives. But Baylor College of Medicine’s Dr. Virginia Wotring suggests other methods may offer more advantages. Her research appears in the current issue of the journal Microgravity.

Currently, female astronauts may take daily oral contraceptive pills continually during space missions to prevent menstrual bleeding. However, use of long-acting reversible contraceptives (LARCs) may stop their cycles and would provide other benefits, said Wotring, assistant professor in the Center for Space Medicine at Baylor.

In her new review paper, Wotring points out that long-acting reversible contraceptives can be safe and reliable for stopping menstrual cycles. This form of contraceptive does not require a daily pill, so it would be more convenient to female astronauts in space. Another advantage of a long-acting reversible contraceptive is that it minimizes waste from contraceptive pill packaging on space flight.

Wotring’s research was driven by the desire to identify safe birth control and menses suppression options for female astronauts during their long duration missions and training but can be applied to women right here on earth. She emphasized one of the biggest issues related to oral contraception – the risk for blood clots.

“Oral contraceptive birth control pills double a woman’s chance of getting blood clots,” said Wotring, noting that age also is a risk factor. “If you are taking the pill and you reach a certain age or have other risk factors your doctor may tell you to stop the pill and try something else because your risk of getting blood clots is too high.”

In addition to age and use of oral contraceptives, other risk factors for blood clots include immobility and long-haul travel – issues sometimes experienced by astronauts during their missions and training but also by people on the ground.

There are some contraceptive pills that have a lower risk rate, she said. “Lower-estrogen birth control gives you a smaller increase in your risk for blood clots but, for reducing risk of blood clots, the best kind of birth control is something that doesn’t have estrogen.”

 A LARC is a small device that is inserted in a women’s uterus as a form of birth control. It contains a small amount of hormones that are similar to the hormones in birth control pills, however, it delivers the drug directly to the tissue, and much less is absorbed into the blood stream. The LARC can last up to three years.

“The dose with the LARC is really tiny, which reduces risk of all side effects, including the risk of getting blood clots,” said Wotring.  “And by happy coincidence, it causes suppression of periods in a lot of women.”

Many women hold misconceptions about having a menstrual cycle every month, Wotring said

“You don’t have to have your period every month to be a healthy woman,” she said. ‘There is no physiological down side to stopping your periods.”

Wotring stresses that a woman’s cycle, and her fertility, can return normal once getting the device removed. 

There are numerous reasons why women may want to stop or control their menstrual cycle, both in space and on earth. Wotring calls for more research and better understanding of the options women have in controlling or suppressing their periods.

“We are really hoping that more American women become aware of this type of contraceptive, which is less popular in the United States than pills,” she said. “Women can go to the doctor and get their period and contraception under control for up to three years. It is very easy, with a low instance of side effects.”

Wotring jointly conducted this study with Dr. Varsha Jain, visiting researcher at the Center of Human and Aerospace Physiological Sciences at Kings College in London and National Institute for Health Research academic clinical fellow in obstetrics and gynecology.

Jain was funded through the Royal College of Obstetricians and Gynecologists/American Gynecological Club Travel fellowship 2015, Bart’s Health NHS Trust, UK and the National Institute for Health Research, UK. Jain received honorary academic support from King’s College London and Baylor College of Medicine’s Center for Space Medicine. Wotring’s research was funded by NASA’s Human Research Program and BCM Center for Space Medicine.