Found in the spellings of Atkinson, Aitchison, Acheson, Aicheson, and Aitcheson, it is as a patronymic form of the medieval male given name Atkin or Adkin, itself a double diminutive of the Hebrew name 'Adam', meaning 'red earth'.
But for natural conception, age rarely keeps women from getting pregnant until they are over 40. Even in their early 40s, though, most women are still able to get pregnant, especially if they use ovulation prediction.
It is laughingly said that pregnancy is the best antidote to pregnancy; that you cannot get pregnant while you are pregnant. This is true in all but the rarest of rare cases. There are many reasons that a woman cannot get pregnant when she is already pregnant. For one a woman will stop ovulating once a pregnancy has occurred; also a mucous plug forms at mouth of the cervix, sealing off the uterus for all practical purposes. However there are freak occurrences in nature which make it possible for a woman to fall pregnant even while she is pregnant.