5Ziade SM. Maternal and perinatal outcome in nulliparous women aged 35 and older [J]. Gynecol Obstet Invest, 2002;54(1):6- 10.
6Heffner LJ, Elkin E, Fretts RC.Impact of labor induction, gestational age, and maternal age on cesarean delivery rates [J]. Obstet Gynecol, 2003, 102(2) :287 - 293.
7Kozinszky Z, Orvos H, Zoboki T, et al. Risk factors for cesarean section of primiparous women aged over 35 years [J]. Acta Obstet Gynecol Scand, 2002, 81 (4) : 313- 316.
