I only weighed 90lbs when I got pregnant, I had a nine pound baby & I only have one small strech mark. I used lotion on my belly everynight & dont scratch no matter what -thats what causes them. You know how people say it looks like freddie crugar got a hold of them cause of the big long streaks, it because you scratch while your skin is stretched & it damages the skin, you should use lotion everywhere & dont scratch anything. I got a little spot on my belly when I was pregnant & scratched over it a couple times & then thought oh crap, I put he lotion on but to late thats the only one i got. I gained 29lbs. I weighed 119 when I delivered my 9lb 1 oz boy. I weigh more then that now-lol. Comgratulation on the good news, prepare to be drove crazy. I had 2 kids, thats why I switched dogs