Dlugosz L, Belanger K, Hellenbrand K, et al. Maternal caffeine consumption and spontaneous abortion: A prospective cohort study. Epidemiology 1996; 7(3):250-55.
Noehr B, Jensen A, Frederiksen K, et al. Loop electrosurgical excision of the cervix and subsequent risk for spontaneous preterm delivery: a population-based study of singleton deliveries during a 9-year period. Am J Obstet Gynecol 2009. E-pub ahead of print.
Li D, Liu L, Odouli R. Presence of depressive symptoms during early pregnancy and the risk of preterm delivery: a prospective cohort study. Hum Reprod. 2009;24(1)146-53.
