Star6: It is daft isn't it. I found the info on a US site about drinking the stuff thoughout pregnancy, one cup in the first trimester, two in second and 3 in 3rd. I think it was babyfit or the US babycenter site. The list of forbidden foods is different too.. just shows that no-one really knows for sure about these things..
It's supposed to strenghten/tone the uterus making labour faster.
I used it last time from 28 weeks without a problem. Had to be induced for pre-clampsia and it took 5 days so definately didn't bring on labour in me.
I was able to push the baby out very quickly though, my womb shrank down very fast, the MW who checked me a couple of days later was amazed at the progress and had little or no afterpains.