Read a paper long time ago, something to do with increase of sulfur in the brain

USA, what my wife’s OB told her. 20 years ago.

Oh I was hoping for a written down reference from an organisation responsible for giving medical advice rather than an single doctor.

Well here’s one:

https://health.clevelandclinic.org/pregnancy-safe-medication...

While they do list some medicines, note that they also say check with your doctor first.

The OB will give you a list of what you can and can’t take. Tylenol is the only pain reliever you can take.

I’d say that qualifies as physician advice.