In the first fire, a woman in her 80s died in her third floor apartment on Valentine Avenue.
The fire broke out in the six story building just after 2:45 a.m.
After firefighters put out the blaze, they wheeled a pregnant woman away from the fire building on a stretcher.
The woman, apparently a neighbor of the victim, went into labor during the fire. She was taken to the hospital.
In the second fire, another woman in her 80s died in a fire on North Street in the University Heights section of the Bronx.
The second fire also broke out on the third floor.
The victim was pronounced dead at the scene.
Both fires are under investigation.