the way that female phisiology is optimised for child bearing centers on blood flow to the placenta (and a whole new human), and then the very sudden removal of

the way that female phisiology is optimised for child bearing centers on blood flow to the placenta (and a whole new human), and then the very sudden removal of that WHOLE system in a survivable way is focused on two things, one is that the internal structure of the womb, literaly acts as a mechanical shear to sever the placenta, and two, instant powerfull but highly controlled, clotting, which as we all know can sometimes over or under react. that such a complex system can continue to function at all in zero gravity is a testement to how conservative natural design and engineering is,and "solving" the problem faced by female astronauts is going to require a much deeper understanding than throwing a hormone at it. Nature has solved problems like this many times, by the simple expedient of throwing more males at it untill the problem goes away. or as I like to answer sometimes as to how I am going to solve a problem I say "I will use anger and stupidity, wish me luck"