"A death is considered preventable if the committee determines that there was at least some chance of the death being averted by one or more reasonable changes to patient, community, provider, facility, and/or systems factors."
They said that the deaths are preventable, not the conditions themselves.
Deaths by suicide and drug abuse are indeed preventable. Are you misconstruing the word preventable to mean 100% preventable?
Do they consider treatments that couldn't possibly be performed on every pregnancy that it might help? (due to finite medical resources, cost that insurance companies won't pay, etc.)
I'd much rather see a focus on the basics that other countries do that are consistently missed. Especially when it comes to over-using C-sections and how race plays into treatment.
While it's unwise to try and simply reduce all mental health conditions to 'circumstances' or 'chemical imbalance', there are lots of things you can do to keep a person in balance to the point that any latent conditions they have aren't enough of a problem to interfere with their daily lives. Motherhood is already very difficult so it is worthwhile to try and keep as many challenges out of a new mother's life as we can.
By that definition, cancer is preventable. Actually, nearly every possible cause of death is preventable if you're definition is "doing something might reduce risk factors".
That's not the normal usage of "preventable death".