There are many decisions on the way to a child being born, some of which are up to the man and some up to the woman, some up to both. All of them have to be made. A man could get a vasectomy and now he's made the unilateral decision regarding children by your reasoning.Regardless of why she has the option, the fact is that the system currently holds a man responsible for the unilateral decision of a woman.
The man consented to an activity that can result in children. He's already responsible for the outcomes of that consent.She opted not to get an abortion, thus a child was born and the man is responsible