When is post-natal bleeding established?

If the fetus is expelled before the completion of four months, is the woman considered to be in a state of post-natal bleeding?

The scholars said: Post-natal bleeding is established when the creation of a human being is discernible in the fetus, and the creation of a human being is discernible from eighty days onward.because of the saying of Allah the Exalted: [al-Hajj:5] The clot begins from eighty days, so from eighty days onward it can be formed. So when it is formed and its legs, hands, neck, and head are distinguished, the blood becomes post-natal bleeding blood, and the blood before that is corrupt blood that does not prevent prayer, fasting, or a husband.