Justin Voight had a twin sister who was stillborn.
This episode has the similar ending to CSI episode Gentle, Gentle. Where it was discovered the younger sibling was responsible for an infants death. Fortunately, the baby in this episode survived.
Tana didn't want the baby, but claims her family's religious beliefs prevented her from getting an abortion. So it's a little understandable as to why she wanted to get rid of the baby.