Fearful he would damage the phone, containing photographs of their child, the victim blocked the doorway to prevent him leaving the room, he said.
"He tried to move the victim by grasping her upper arms, causing bruising. He threw the phone at the victim, causing her to duck and fall to the ground. While she was on the ground the defendant kicked her legs with at least one kick hitting her stomach ... she curled up into a ball to protect her baby."
When Judge Moss questioned Clarke about what triggered him to behave this way, he remarked "drinking".
The judge told him he needed to do whatever it took to get back on track so he could be a good role model for his children.
"It's alcohol that starts it. You have to do whatever it takes ... I mind about the violence around children. It does their brains [an] injury ... You can tell your kids what to do but it's what you do that matters, as they copy us.
"We need to protect the babies. There is a lot of work to be done for your babies to be safe."
Defence lawyer Frank Minehan said the extended family were helping the couple and they were going to relationship counselling as they wanted to work at their relationship.
"They want to maintain the family unit," he told the court.
Judge Moss remanded Clarke for a pre-sentence report, ordering he attend at the police station on set days to undertake an alcohol breath test before visiting the family.
He is due back in court on November 21 for sentencing.