I'm 35 and am pg for the first time (almost 8 wks). I also regularly teach a section on prenatal development to my dev psych class, and we discuss the latest research on the relationship between age and pregnancy risks.
The main thing that happens differently at 35, as km suggested, is the recommendation to do an amniocentesis to check for genetic problems (esp Down's syndrome). There are risks associated with the actual procedure itself (I'll spare you my class lecture notes
- there is quite a bit of info on the procedure available online), but at age 35, researchers have found that the risks of genetic problems are 'equivalent' to the risks associated with the procedure itself. In other words, the risks of not doing the procedure are roughly equal to the risks of doing the procedure. And after 35 the benefits of the amnio begin to outweigh the risks.
Hopefully that helps clarify and not confuse!!