Premenstrual voice syndrome?

If I had a death wish I'd speculate about the exact mechanism, but:

PMVS describes a condition seen in a small number of women. It stands for premenstrual voice syndrome. During certain times of the month, the vocal chords of some woman undego apparently hormonal driven changes. There was a loss in suppleness of the vocal chords, resulting in "less vocal stability and an inability to sing high notes."

Yeah, I'm ripping off Richard Gayle again. It's almost like blogging.