At what age should a woman stop having kids?

Canada
@lisa0502 (1734)
October 21, 2008 10:42am CST
I have known women well into their 40's having kids. I hear that as soon as you turn 40 it can become a high risk pregnancy. So at what age should a woman stop? I am 33 and have 3 kids and 5 step kids. I think that I am done now. I could not picture having a child at 40. I commend all the women that do have kids at an older age. I just find it stressfull at 33. What do you think?