In the early 80's I worked for a laboratory that was doing DNA test to prove paternity. The problem that some of these "Moms" had even back then, was knowing who the real father was. You won't believe the low life bums some of these women dragged in claiming they were the "Dad". We had a couple of them that we had to do several rounds of DNA testing before they managed to name the "father". After having the "honor" of taking a blood sample from some of these creeps you wanted to go take a shower with the bleach to make sure that they didn't give you anything.
IMHO if a women is sleeping around on her husband and conceives a child, she is automaticly declared an unfit mother. The child can then stay with the father that has raised them as his or they can be placed in a home looking to adopt. That way these "mothers" will learn one of two life lessons. To either not sleep around or to keep their mouth shut if they do.
I had the Maury Povich Show running in the background the other day while I was on the computer,and he was doing one of his paternity shows. One girl on there was 17 years old,and had already ran 9 males (I won't say men)through DNA testing without finding "my baby's daddy",and said she had 3 more possibilites,and was looking forward to returning to the show to prove one of them was the father.
BTW,one of these young males (probably about 20) already had 6 babies by other women. No job,but kept saying "I support my babies,I support my babies". This probably means he buys them a pack of M&M's sometimes.