Is it permissible for a tired pregnant woman to combine the Maghrib and Isha prayers, and is it authentically reported that the Messenger of Allah (peace be upon him) combined them without an excuse?

The Prophet, peace and blessings be upon him, combined the Dhuhr and Asr prayers, and the Maghrib and Isha prayers in Medina, without fear or rain, to alleviate hardship for the Muslims. Scholars have differed regarding this combining of prayers. Some interpreted it as a "pictorial" (or apparent) combining, which means performing Dhuhr at the very end of its time and Asr at the very beginning of its time.

It is permissible for a sick person who finds it difficult to perform each prayer at its designated time to combine two prayers. This also includes pregnant women who experience hardship in differentiating between the prayers.