What is the ruling on blood coming from a pregnant woman? Can acts of worship be performed during this time?

The bleeding experienced by a pregnant woman is not considered menstruation, but rather istihada (irregular bleeding). Istihada blood is treated like blood flowing from any other part of the body. Its occurrence only invalidates ablution (wudu), and does not require a ritual bath (ghusl). (Mevsılî, el-İhtiyâr, 1/29-30)

If the bleeding during pregnancy is continuous, the rulings regarding chronic excuses (uzur) apply. In this case, the pregnant woman should perform a new ablution at the beginning of each prayer time; unless it is invalidated for another reason, this ablution remains valid until the end of that prayer time. (Mevsılî, el-İhtiyâr, 1/29)

According to the Maliki school, however, the ablution of someone with a chronic excuse is not invalidated by the entrance or exit of prayer times, but only if something else that breaks ablution occurs. (Ibn Rushd, Bidāyat al-mujtahid, 1/40-41; Desūqī, Hāshiya, 1/116) Therefore, if the chronic condition causes significant hardship and makes performing ablution very difficult, it is permissible to follow this Maliki opinion.

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu