Praise be to Allah.
If a woman fasts and has a baby in her womb and she is bleeding, then her fast is valid, because the bleeding that she experiences whilst pregnant does not affect anything and is not regarded as menses or nifaas, because the child is still in the uterus so it is not nifaas. And it is not menses, because in most cases pregnant women do not menstruate. According to the view of those who say that the pregnant woman may menstruate, they stipulate that the blood should come at the usual time of her previous cycle.
If the woman who asked this question found that it was not clear what this bleeding was and it looked different, in that the bleeding came and went and was different and was not like the old cycle that she had before she was pregnant, then this is all irregular bleeding and her fast is valid. She does not have to make up the fast, praise be to Allah, because the bleeding that appears in pregnancy is usually irregular bleeding that increases and decreases, comes later or earlier than her usual cycle, and varies, so no attention should be paid to it.
But if we assume that it was as it was before she was pregnant and did not change, rather it came according to her usual cycle, then some of the scholars say that this is menses and that she should stop praying and fasting. This was the view of a number of scholars.
Some other scholars are of the view that even if it came according to her regular cycle and as it usually did before, it does not matter and the pregnant woman does not menstruate. This is the well-known scholarly view. But in most cases, the bleeding that pregnant women experience changes and does not remain the same all the time, and according to all scholars this does not count as anything and no attention should be paid to it. Rather her fast is valid and her prayer is valid.
Based on this, in this case she should protect herself with a piece of cotton and the like and do wudoo' for each prayer. So when the time for each prayer begins, she should do wudoo' and pray with that wudoo’ even if the blood is still coming out of her, because she is faced with a problem exactly like the one who suffers urinary incontinence and like the woman who suffers istihaadah (non-menstrual vaginal bleeding) and is not pregnant. This blood is irregular bleeding and does not affect her.
But she should wash her private parts after the time for prayer begins and do wudoo' for prayer and pray according to her situation.
If she joins Zuhr and ‘Asr, and Maghrib and ‘Isha’, as the Prophet (blessings and peace of Allah be upon him) taught some of the female Sahaabah to do, and if she does one ghusl for Zuhr and ‘Asr and another for Maghrib and ‘Isha’, for the sake of cleanliness and energizing herself, this is good, because the Prophet (blessings and peace of Allah be upon him) advised one of the women who were suffering from istihaadah to do that. End quote.
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him).