Contraception in the cosmos: the combined oral contraceptive pill in space.

On 12 April 1961, Yuri Gagarin became the first human to travel into space. His 2-hour voyage aboard the Vostok 3KA-2 definitively demonstrated that humans could survive in space. In the 55 years since Gagarin’s historic flight, hundreds of astronauts and cosmonauts have travelled into space, mankind has visited the moon and it is now realistic to believe that a manned mission to Mars will commence in the foreseeable future. Space is a uniquely harsh environment. The lack of oxygen and presence of microgravity and space radiation predispose astronauts to a wide range of health problems. The microgravity, busy mission schedules and lack of medical equipment make treating acute health problems during spaceflight extremely difficult. Prevention of disease is therefore of the utmost importance and by ensuring astronauts remain healthy, aerospace medicine physicians make a vital contribution to the success of missions into space. The combined oral contraceptive pill (COC) is one medication that could be used to prevent health problems in space. Whilst there is no official requirement for them to do so, the vast majority of the National Aeronautics and Space Administration’s (NASA) female astronauts choose to use the COC whilst in space (P Stepaniak, NASA Flight Surgeon, personal communication, 23 October 2006). Whilst much is known about the physiological effects of the COC on Earth, there has been no discussion of the potential benefits and disadvantages of its use in space. Such a discussion must take into account the effects of spaceflight on human physiology and the fact that modern female astronauts are a highly selected, motivated and, in general, healthy group of individuals. This article aims to review the potential benefits and disadvantages of using the COC during long-duration stays in space. It begins with a discussion of the gynaecological effects of the COC. It then examines how the COC might influence the effects of spaceflight on the human musculoskeletal system. Finally, it explores ways in which the COC could affect other systems of the body in ways that are relevant to spaceflight.