Kot Ador Deng, 25, pleaded not guilty in the Magistrates Court to one charge of assault.

The court heard Deng arrived at the Griffith home about 10am one day in June last year after spending the night locked up for being intoxicated. He became upset when he found his pregnant partner leaving the property with his son and a social worker.

In evidence, the two women told the court they were reversing the car when the defendant opened the left rear passenger door and with his right foot kicked the mother of his three children in the left side of the abdomen.

Deng then became more aggressive and yelled death threats at his partner and banged the vehicle with his hand as it drove away.

The women made a complaint to the police later that day and Deng was arrested.

The unborn child was uninjured in the attack and the baby attended court with its mother on Monday.

But defence lawyer Kathryn-Magnolia Feeley argued the assault and the death threats did not occur.

Deng, from the witness box, admitted he was angry with his partner because she threatened to call the police. He said he was speaking to her when the social worker suddenly reversed, running over part of his foot.

Ms Feeley said the three-hour break, during which the victim went shopping before going to the police, was not the normal behaviour of a pregnant person who had been kicked in the stomach.

But the prosecution said it was Deng's evidence that was unreliable.

Magistrate David Mossop found Deng guilty of the assault.

Deng was denied bail and will be sentenced at a later date.

Ms Feeley said she would consider the verdict before deciding on an appeal.