A teenager from Flintshire assaulted his pregnant partner and she blacked out.
It was one of a number of incidents where she had been assaulted, a court was told.
Sean Lloyd, 18, admitted a series of assaults against her which had gone on over many months and some had not been reported.
Police had been called on occasions but the partner refused to make a statement.
The couple had lost a baby previously, Flintshire Magistrates Court was told.
But on January 24 after he was released from custody, he grabbed her, headbutted her, punched her to the face and produced a knife. He threatened to kill her and said he would stab her
Lloyd was said to have run at her with the knife, she curled up against a wall to protect herself and ducked as he brought his arm down.
Then last Sunday, the Mold court was told, he pushed her to the floor, she was screaming and tried to run off. He followed her and grabbed her around the throat.
She believed she had blacked out and the next thing she remembered was Lloyd being there and she felt a hard bang to the head.
He grabbed her stomach and put pressure on her knowing that she was pregnant, said prosecutor Jim Neary.
The victim was hysterical and crying and the police were contacted and she was taken for a scan.
Lloyd admitted a series of six assaults upon her and making a threat to kill.
Mr Neary said Lloyd had told police he was sorry for what he had done and had threatened to kill himself.
Defence solicitor Fiona Larkin applied for bail and said he could live at an address in Bryn Mawr Road, Holywell, where he could be curfewed overnight.
He could access the help he needed, she said, but magistrates remanded him in custody to appear for sentence at Mold Crown Court next month.
Miss Larkin said Lloyd had fully co-operated with the police, admitted what he had done and pleaded guilty at the first opportunity and had shown genuine remorse.
He had mental health issues and appreciated that the relationship was not good for either of them and had to end.
They had lost a baby previously and there was now one on the way, she explained.