Stretch marks may be hereditary, meaning that if an expectant mother's sisters or mother got stretch marks, that mom may get them as well. There are several other factors that may result in a woman getting stretch marks.
Some women get stretch marks and others do not. Some of the factors that play a role in whether or not a woman will get stretch marks during her pregnancy include the age at the time of pregnancy. Younger mothers are more likely to get stretch marks than older mothers. Whether or not a woman gains too much weight during the course of the pregnancy can affect stretch mark development as well. Moms who are carrying multiple babies, or very large babies, are also more susceptible to stretch marks.