Fertitility Fallacy

de bene esse: literally, of well-being, morally acceptable but subject to future validation or exception 

It Is widely believed TO BE harder for women in their thirties to get pregnant.

Take this often-cited statistic: one out of three women over the age of 35 will not have conceived after a year of trying.

Except… the data on which that statistic is based is from 1700s France. http://bbc.in/18auRMU