Physician expected to attend Agent 99 when she is to give birth.
It is unclear precisely what sort of doctor Baker is. His expectation at the birth implies obstetrician but Max's later description of him as "baby doctor" suggests pediatrician. It is possible that he is both.
Several months after the birth of the twins 99 is still seeing him, telling Max that she is late because Dr. Baker had an emergency tonsillectomy - his own.