The vicious attack happened in the Burren Meadow area of Newcastle this morning, Sunday, 8 April.
At approximately 5:35 am it was reported to police that a male forced his way into an address and assaulted the pregnant female occupant.
She sustained non-life threatening injuries after she was punched and had a bottle smashed on her head.
The females young daughter was also present.
The female was left distressed by her ordeal.
A 35 year old male was arrested a short time later in the area of Westland Avenue in Newcastle and is currently in custody assisting police with their enquiries.
Detective Sergeant Bell is appealing to anyone who noticed any suspicious activity in the Burren Meadow or Westland Avenue area of Newcastle or anyone who has information that would assist with police enquiries to contact Detectives at Ardmore on the non-emergency number 101, quoting reference 407 08/04/2018.
Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111, which is 100% anonymous and gives people the power to speak up and stop crime.