It can be more than a little disconcerting to hear yourself described as "elderly" or "of advanced maternal age" when you only recently celebrated your 40th birthday, but, in the eyes of the obstetrical profession, that's exactly what you are. Obstetricians don't care how young you look and feel, or whether you can still fit into the same size of jeans that you wore 20 years ago: they're concerned about the age of the eggs that are nestled away in your ovaries.