What is the ruling on the prayer of a pregnant woman who suffers from excessive vaginal discharge of varying colors and consistency, and is she required to change her underwear for every prayer, and what should she do if the discharge continues throughout the day?

Normal discharges are pure and necessitate ablution (Wudu'). As for yellowish discharge, it is impure (najis) and necessitates istinja (definition)' (washing the private parts) and washing of clothes. When in doubt about the emission of discharge, the original state (i.e., its non-emission) is assumed. If you are certain of its emission, then ablution (Wudu') is obligatory; and if it is yellowish, then purification of the area is obligatory. If its emission is continuous without interruption, then the affected woman's ruling is the same as that of a person with incontinence (Sahib al-Sals): she performs ablution after the entry of the prayer time and prays with that ablution until the time expires. She should take precautions to prevent the spread of impurity, and it is not necessary to renew the sanitary pad for every prayer.