A NASA study has uncovered that women are more susceptible to physiological, psychological and behavioural changes that occur during spaceflight.
The report stated that women have greater loss of blood plasma volume than men during spaceflight and women's stress response characteristically includes a heart rate increase while men respond with an increase in vascular resistance (resistance to flow that must be overcome to push blood through the circulatory system).
The study, titled "Impact of Sex and Gender on Adaptation to Space" also found that urinary tract infections in space are more common in women, although they can be successfully treated with antibiotics.
The researchers, however, observed that the disparity in spaceflight data available for men and women, who have flown to space - 477 men versus 57 women as of June 2013 - makes it difficult to derive concrete conclusions based on sex and gender alone.
"But this is the first major integrated examination of the issues of sex and gender in relationship to space exploration," said Mark Shelhamer, chief scientist for NASA's Human Research Programme at the Johnson Space Center in the US.
According to him, there are, in many cases, "sex-based differences in the response to the stressors of space flight".
Radiation also presents a major hazard for space travel.
It has been reported that female subjects are more susceptible to radiation-induced cancer than their male counterparts.
"Radiation permissible exposure levels are lower for women than men astronauts," the report added.
The US space agency, in partnership with the National Space Biomedical Research Institute (NSBRI), is researching risk-reducing counter-measures and developing technology to advance human health and ensure operational performance in deep space.
"The International Space Station (ISS) provides us with years of biological data on male and female astronauts, and many of them continue to participate in ground-based studies to evaluate the lasting effects of spaceflight," said Marshall Porterfield, director of space life and physical sciences research at the NASA headquarters in Washington, DC.
