Plenty of people have children in their thirties and even into their forties and no one looks askance at such mothers. The average age for a first-time mother is fast approaching 30 as more women start their careers before starting their families. So I had to do some research into what exactly this whole “advanced maternal age” thing really meant and why my chart at the hospital was suddenly graced with the tag “high risk.”

Apparently, the determination of advanced maternal age comes when the mother-to-be is age 35 or older. This doesn’t mean as much as it seems to, though. Most of the risks associated with pregnancy and the health of the fetus rise slowly over time. This happens because of female biology. A woman is born with all of the egg cells she will ever have and over time those eggs get older as she does. Older eggs increase the risk of some genetic problems, such as Down’s syndrome, or of miscarriage and an older body increases the risk that the woman herself might develop some pregnancy issues such as gestational diabetes or preeclampsia.

At age 25, a baby’s risk of Down’s syndrome, trisomy 21, is 1 in 2500. When she reaches 35, the risk has risen to 1 in 400. The risk of miscarriage rises from 10 to 20 percent as a woman goes from her 20s to her thirties. Women over 35 have double the chance of developing gestational diabetes, high blood sugar. We advanced maternal age preggos are also more prone to preeclampsia, the condition of high blood pressure in late pregnancy.

While these can be scary statistics for women who become pregnant over the age of 35, most of these risks are still quite low. The most important things for those of us in the advanced maternal age category is to keep up on our doctors appointments, take prenatal vitamins with folic acid and be aware of our general health care. As for myself, I’m watching what I eat, following my doctor’s instructions and celebrating the idea that being an older mom has given me more life experience and made me more prepared for raising my child-to-be.