Most of the time, the hoes don't even know who the father is. Ol girl who got killed in Maryland tested 3 other nikkas previously.
So every nikka who she thinks is the father has to get a vasectomy or fail jail, or are we going to keep doing DNA test to find the true culprit? How exactly would your plan work?
Once the baby is born, a dna test is administered and if the male is the father he can choose to voluntarily support the child or decline to support the child and choose between vasectomy or jail time. If the male isn't the father, he's not liable for the responsibility of the child. Simple.