While some of these figures might actually be due to faulty data or divergent definitions in other nations, there is another factor that neither you nor your friend seem to be acknowledging - how the high cost of health care in this country is impacting the way women seek care during, before, and after childbirth.

Giving birth in this country is extremely expensive (https://www.theguardian.com/us-news/2018/jan/16/why-does-it-...) and we have a ton of people who are uninsured, underinsured, have high deductible plans, or simply aren't in stable enough financial situations to risk going to the doctor for prenatal/postnatal care when the $40 copayment or $300+ tests the doctor runs could delay their rent check that month.

When you talk about people coming into the hospital with comorbitieis, it's an easy next step to say "eh not our fault, that's on the patient, not on the medical system," but it kind of is on the medical system (or the insurance system, if you choose to differentiate the two) if the inability to afford healthcare is causing so many people to die of secondary causes when something serious enough to warrant it (in this case, pregnancy) forces them to go to a hospital.