However, we do know, he never called 911 for help, never pressed the panic button, never screamed for his neighbors to help, never had a loud enough fight with her to get anyone's attention.
And we do know that strangling an adult takes several precious minutes of time. And it said that she was 'actively strangling' the child. So the child was still potentially able to be revived. So if just those few facts are correct, he didn't place the priority on his child's revival but placed it on revenge against his pregnant wife.
Even if they add in more facts, the few that we do know are pretty damning. The child was still potentially able to be revived, and he did not call for medical help to make that happen. There is no way that he did call for help and it didn't make it into the confession.
And there is no way that he could 'know' the child was beyond help, if his wife was still actively strangling the child. A baby can look deceased and still be able to be revived in cases like this.