They have found some women who repeatedly lose their babies early in pregnancy, do so because they are too good at letting imperfect embryos implant in the uterus.
Professor Nick Macklon, a consultant in obstetrics and gynaecology at the Princess Anne Hospital in Southampton, said many women who suffered repeated miscarriage “feel guilty that they are simply rejecting their pregnancy”.
He continued: “But we have discovered it may not be because they cannot carry; it is because they may simply be super-fertile, as they allow embryos which would normally not survive to implant.\”
The point being that the majority of conceptions are miscarried because the womb rejects them as being flawed (I assume for genetic reasons). These flaws are usually detected early and rejected early. Some women don\’t reject them early and thus appear to have a series of miscarriages. When, much more likely, they\’re having exactly the same number as anyone else, they\’re just having them later.
And which brings us back to the rising foetal abnormality rate in older mothers. That is, of those that do implant and would, if left alone, survive to term. The standards by which rejection is judged seem to decline in older women and the fairly decent grounds that for the young there\’ll be another opportunity of have a healthier baby in a moment, the older one is the fewer such chances (no, not on the bonking grounds, but on the number of eggs left/womb being able to carry basis) and thus why the hell not accept lower quality in this last hurrah?
Very minor pedantry point: it’s not that you’re running out of eggs: women are born with (?) millions and release just one every month (give or take incidence of fraternal twins etc).
It is that the menopause is looming – it is lack of time, not materials.
PG: http://goaskalice.columbia.edu/women-and-their-eggs-how-many-and-how-long