My RE quoted it to me, and I believe him. Of course, this is an average; some women have lower peaks, some women higher peaks.
Here's a few sources I found online:
http://www.asrm.org/Patients/FactSheets/reproaging.pdf
http://unisci.com/stories/20022/0430021.htm
http://www.nlm.nih.gov/medlineplus/ency/article/001191.htm
http://archives.cnn.com/2002/HEALTH/04/30/fertility/index.html
http://www.pbs.org/wgbh/nova/baby/fert_text.html
http://www.guardian.co.uk/print/0,3858,4404085-110418,00.html
Thanks, I will look at those articles. I don't doubt the honesty of anyone using the number, but I do wonder how the information was "discovered."
Interesting. I see they didn't control for lifestyle factors, such as STD history, so the practical utility of the number is low. However, I can at least see how they got the number.