I think to a large extent, it's how your particular care provider approaches things. There's someone on my f'list (and she can out herself when or if she feels like it) who falls into the category of "advanced maternal age" plus has thyroid issues plus asthma who delivered in a birthing center with a midwife. Its not a guarantee that your health care provider will shuttle you into "high risk" and for me, it's mostly an annoyance. PCOS raises the risk of miscarriage and gestational diabetes, thyroid issues can also relate to miscarriage and intrauterine growth restriction, so Dr P wants to get them to do the extra monitoring because they're more familiar with what to look for earlier on, so that he feels better. At least that's what he tells me. He basically said that he doesn't anticipate any serious problems, but if there are any, he'd rather have me already known over there than suddenly showing up on their radar at 28 weeks going into labor or something like that.