When we first met Leah, Kailyn, Chelsea and Jenelle on "16 and Pregnant," they were still expecting and had no idea of the hardships that young motherhood would present them with. Needless to say, they went through a lot on "Teen Mom 2": Leah experienced some major relationship highs and lows, Kailyn found herself in an ugly custody battle with her ex-boyfriend Jo, Chelsea finally let go of the hope that she and Adam could make things work and Jenelle not only gave up custody of her son, Jace, but wound up in a load of trouble with the law.
+ None of their lives have been easy, but think about all four girls' personal achievements and pitfalls, then take the poll and tell us whose story had the biggest impact on you.