Influence of prepregnant body mass and weight gain for gestation on spontaneous preterm delivery and duration of gestation during adolescent pregnancy Scholl, T.O.; Hediger, M.L.; Salmon, R.W.; Belsky, D.H.; Ances, I.G. American Journal of Human Biology the Official Journal of the Human Biology Council 1(6): 657-664 1989 1520-6300 10.1002/ajhb.1310010603 https://eurekamag.com/research/059/858/059858769.php