Silvia Azaña, an embryologist at inviTRA, tells us in this video when maternal age is considered advanced:
A woman is biologically classified as having advanced maternal age from 35 to 40 years. This is because her body may no longer be as well prepared to handle and go through a pregnancy. The passage of time has a significant and noticeable impact on a woman's ovarian reserve, that is, the number of eggs remaining in her ovaries. Moreover, the quality of the eggs is impacted as well. Older women tend to have eggs of poorer quality because they present an increased rate of chromosomeal alterations. The biggest consequence of this is that it raises the chances of having a miscarriage or having embryos that are chromosomally altered, which would complicate the implantation process in the uterus.
