Original says 유산입니다 before going into the symptoms of pregnancy dialogue
유산 - miscarriage
입니다 - formal speech to essentially confirm the verb, or declaration
We use 입니다 more or less as a present tense formal speech padding for a declarative statement. The correct translation is “It is a miscarriage”. If the doctor was unsure it would probably be stated as 유산아마도 which would be translated as “It’s probably a miscarriage”. We use 아마도 as “probably” when you’re pretty sure something is but not 100% certain it is. So more weight than the english “maybe” but still not fully certain.
So no, it’s not a mistranslation. The only part in the original that mentions the miscarriage is that panel. The rest goes on about pregnancy symptoms since they didn’t know he was pregnant. I say wait for more information this Thursday when there is hopefully more information about it (assuming the characters have a talk about it, whether it’s between the two or amongst the family unit or however the author decides to address it). But if you’re banking on it being a mistranslation, that is not the case, unfortunately.
According to Facebook (trying to check) there was a mistranslation and the good one is tanto is there a danger of miscarriage, not miscarriage. Plese someone confirm