Actually, that's one of the few parts of his weird ranting that has some basis in reality. It comes down to simple biology - women have periods and can get pregnant, and those add all kinds of hygiene and medical complications into the mix. Reliance on drugs to control menstruation is a problem (what if their shelf life isn't long enough, or they get lost or damaged, what about the extra weight required to carry them, the possible interactions with other medical interventions, the effects on physiology, and so on), and anything other than eliminating them completely adds more complication to the already pretty tricky hygiene arrangements and yet more weight needed for supplies. And while you might hope the chance of anyone getting pregnant would be very low, expecting people not to be people on multi-year expeditions would be somewhat optimistic. And no matter how you try to prevent it, the consequences are so huge that even a tiny risk could be unacceptable. Of course, that issue could be prevented just as easily by an all-female expedition, so it's more an argument in favour of single gender rather than men specifically.