Because theres something about having a child and knowing that the child is a peice of you. Maybe their husband has always wanted children… and if she had one with him. Maybe she thinks he'll be more likely to stick around… seeing what all she had to go through to have the baby. And maybe she thinks he will see what a wonderful child they had together and see what a wonderful family they made.
Although truthfully if a man wants to leave, he will always have that desire. Even if after a child he decides to stick around… the women would always know in that back of her mind. He's not sticking around for the marriage. Really if a marriage is falling apart is best to decide what your going to do before getting pregnant. No need to get a baby mixed up in all the drama. Alot of times if you don't have a good marriage before a baby… your marriage will not improve with a baby. Because with a baby theres less time to focus on your marriage, and less one on one time.You have to really try harder to make husband and wife time. Thats why its always best to create a stable marriage before creating a baby.