Pretty much the usual if someone looks closely at a commonly held belief about a medical issue. The usual dramatic belief that fertility drops off sharply at 35 is based on French birth records from 1670 to 1830. Human fertility is very hard to study. Women who are trying to have their first child at age forty may be less fertile than average. And so on.
What’s actually known about women’s biological clocks?
Pretty much the usual if someone looks closely at a commonly held belief about a medical issue. The usual dramatic belief that fertility drops off sharply at 35 is based on French birth records from 1670 to 1830. Human fertility is very hard to study. Women who are trying to have their first child at age forty may be less fertile than average. And so on.