Antrim Hospital is run by the Northern Health Trust
Five babies are among 11 deaths being probed at the Northern Health Trust.
It is not clear at this stage whether the deaths were unavoidable.
Cases being investigated involve patients who were seen in the emergency, obstetrics, gynaecology or X ray departments.
Health Minister Edwin Poots has told the Assembly he is aware of 20 cases where the trust's response was said to be below standard.
Poots said the cases said he sent a "turnaround team" to the trust and that the cases date from 2008 until the present.
He said: "I wasn't happy with the Northern Trust, I wasn't happy with the way things were being done there and that's why I put a turnaround team in."
"We do need to offset that with the fact that the Northern Trust was dealing with tens of thousands of cases.
"The Northern Trust is in a considerably better place than when I inherited it in 2011."
Nine patients have also been recalled.