It is understood the Maternity Unit at the Lagan Valley Hospital in Lisburn will close within a year to 18 months.
It is understood the Lagan Valley maternity unit will be closed
It is thought that an announcement could be made after a meeting of the South Eastern Trust later.
More than 1,200 babies are born each year at the midwife-led unit which serves more than 125,000 people.
The MP for the area, Jeffrey Donaldson of the DUP, said he was totally against the closure. "The unit has been very successful," Mr Donaldson said.
"My message this morning to the trust board will be absolutely clear - we will fight this all the way."
Last year the hospital's maternity unit was highly recommended for significantly reducing the number of caesarians sections.