What is the Ruling if a Woman has a Miscarriage?

Question :

Some pregnant women face a problem with miscarriage of pregnancy, some of them when the foetus is fully formed and some when it is not yet fully formed. I request clarification on the matter of prayer in both situations.

Answer:

If a woman miscarries what appears, due to the presence of head, hands and feet etc., to be a fully formed human being, then she is considered to be in a postdelivery state, and the ruling for her is that of postpartum bleeding. She does not pray, nor fast, and it is not permissible for her husband to have sexual intercourse with her, until she becomes clean, or completes forty days. If she becomes clean in less than forty days, she must perform Ghusl, pray and fast in Ramadhan, and it becomes permissible for her husband to have sex with her.

There is no minimum number of days specified for postnatal bleeding, so if ten days, or more or less have passed since the birth, she must make Ghusl and she must act in the manner of the purified women, as we have said. If she sees any blood after forty days, then it is the blood of illness and she should fast and pray with it, and it is allowed for her husband to have sex with her. She must perform Wudhu' for every prayer, like a woman with continuous vaginal bleeding, according to the Hadith of the Prophet, who said to Fatimah bint Abi Hubaish, may Allah be pleased with her, when she was suffering from continuous vaginal bleeding:
"... so make Wudu' for every prayer.

And when the blood of the menstrual period follows after forty days, she falls under the ruling of menstruation, and she is not allowed to pray or fast until she becomes clean, and she may not have sex with her husband.

However, if it is not clear that the foetus which is expelled from the woman is of a human form, being like a lump of flesh, without shape, or it is only blood, she will in this case fall under the ruling of one with vaginal bleeding, not of post- natal bleeding, nor of menstruation. She must pray and fast in Ramadhan and it is permissible for her husband to have sexual intercourse with her. But she must make Wudhu' for every prayer, protecting herself from the blood with cotton or some such thing, like one with continual vaginal bleeding, until she becomes clean. And it is permitted for her to join the Zuhr and Asr prayers and the Maghrib and 'Isha' prayers, and it is lawful for her to make Ghusl for the combined prayers and for the Fajr prayer, based upon the authentic Hadith of Hamnah bint Jahsh, may Allah be pleased with her, regarding this, because she falls under the ruling of continuous vaginal bleeding, according to the scholars. And Allah is the Granter of success.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 2 Page 118-119-120