How does a woman menstruate in space?
April 12, 2007 12:53 PM   Subscribe

How does a woman menstruate in space?

This is the product of a terrible lunchtime discussion at work: how does a woman menstruate in space? We assume that on earth menstrual fluid leaves the womb and travels down the vagina and out the body because of gravity. So what happens when there's no gravity?

The best Google has turned up is a section on "Menstrual Efflux and Retrograde Menstruation" in this report from the American Physiological Society. All the report really says, though, is that "the role of gravity in menstruation should be investigated to determine whether retrograde menstruation is increased and how peritoneal fluid is distributed." Which is a question, not an answer.

So. Period in space. Put a tampon in. Is there anything on it or does everything just stay inside you? Move around? Why?
posted by anonymous to Science & Nature (13 answers total) 9 users marked this as a favorite
Well, the uterus contracts during mestruation to expel the blood, etc., so gravity isn't entirely responsible. The uterus still contracts in space I assume.
posted by robinpME at 1:03 PM on April 12, 2007

what robinpME said. the contractions squeeze everything out like toothpaste from a tube. uh, kind of. or, think about how people vomit while standing upright on earth.

except, god willing, not as... abruptly.
posted by white light at 1:10 PM on April 12, 2007 [4 favorites]

What the others said. Not to snark, but haven't you heard of menstrual cramps?
posted by different at 1:23 PM on April 12, 2007

Ob/gyns know plenty about how to chemically manipulate the strength or presence of contractions (think: labor and delivery). For one thing, rising prostaglandin levels -> uterine contractions -> flow and cramps. More prostaglandin = more forceful contractions.

The most obvious solution I can think of is to just take low dose birth control pills and skip the placebo week, thereby eliminating bleeding altogether. No woman is going to feel like hassling with constant tampon/pad changes with that big spacesuit in the way.
posted by nakedcodemonkey at 1:24 PM on April 12, 2007

Oh come now, he isn't being that dense. Gravity does indeed play a part in this. Have you not laid on your back all night during a period and have the experience of standing up and getting the "rush". I am going to go with nakedcodemonkey and say that I am sure at this point, they just delay the period until the astro. returns.
posted by stormygrey at 1:32 PM on April 12, 2007

I didn't read the question as being "What should an astronaut do if she's going to get her period while on a mission", but more as a theoretical "if there's no gravity, will you still get your period?" Hence my answer.
posted by different at 1:36 PM on April 12, 2007

With a tampon on, the fluid would wick out too.

I can't look at askmefi anymore without thinking of the April Fool's day page. Curse you, jessamyn!!!
posted by selfmedicating at 1:53 PM on April 12, 2007

Remember that the toilet equipment on the space shuttle and station have a vacuum effect. Wouldn't that just suck out whatever menses didn't wick out with a tampon?
posted by taumeson at 2:10 PM on April 12, 2007

NASA has a document on gender issues related to spaceflight. It says that most astronauts who are female choose oral contraceptives during spaceflight. I'd imagine that many keep taking then during the flight, so that they don't have period. However, the section on "Menstrual Efflux and Retrograde Menstruation" may be of interest:

Because of the effects of gravity, the blood products and cellular debris usually stay confined to the pelvis. The development of endometriosis is multifaceted, but exposure of the pelvic peritoneum to menstrual blood products is thought to be the primary cause of its development. Endometriosis is also primarily a pelvic problem in part because gravity keeps the menstrual products confined to the pelvis.

It continues with "Although medical debriefing data from shuttle flights have not supported concern that retrograde menstruation increases during spaceflight."

However, over at the Canadian Space Agency, we have an actual FAQ about periods in space. Canada suggests that microgravity and endometriosis are not likely linked.
posted by acoutu at 2:46 PM on April 12, 2007 [1 favorite]

Generally, NASA women astronauts use the pill to suppress menstruation when they're in space.
posted by Steven C. Den Beste at 2:47 PM on April 12, 2007

Vacuum effect? Good lord that sounds painful. I experience the morning "rush" as well but if I lay around in bed too long, eventually the uterine contractions seem to do their job, regardless of my horizontal position.

Also this from the Guardian:

Menstruation is not an issue in space travel. Gravity is not essential for menstruation to occur. Menstruation is a very complicated physiological process involving the internal factors of many different hormones, the woman's sexual organs, and the brain.

Very little blood is lost during menstruation. Thus, it is not considered a major "waste management" problem by space flight scientists. When menstruation occurs in a zero gravity environment it will have to be dealt with somewhat differently hygienically. But to do so is far less of a challenge for scientists than the far more important "waste management" problems posed by urination, defecation, infections, and a few other normal body processes and events that can be expected when humans travel in space.
posted by otherwordlyglow at 2:55 PM on April 12, 2007

Oops. Not The Guardian , The Register!
posted by otherwordlyglow at 2:58 PM on April 12, 2007

The morning rush involves fluid that was expelled from the uterus into the vagina overnight. It just sits there until either the vagina overflows on its own or you stand up and the vagina pours out everything it collected overnight.

A tampon works overnight because the fluid is expelled from the uterus into the vagina and then is wicked up by the tampon.
posted by kika at 5:19 PM on April 12, 2007

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