I agree with Camme Lot. I think many women are just using scans to see their baby. I knew one girl who kept making up reasons to have an ultrasound just so they could confirm (over and over) that she was having a girl.
I knew a woman who had a sonographer friend so went for ultrasounds weekly for "fun", bub was born at 27 weeks. Due to number 1's early arrival she "had" to have weekly ultrasounds with number 2 who arrived at 32 weeks. Who can say if the excessive ultrasounds contributed to bubs premature arrival, I don't know but I have read that excessive ultrasounds can indeed lead to premature labour.