8SEOUD M A, NASSAR A H, USTA I M, et al. Impact of advanced maternal age on pregnancy outcome[J]. Am J Perinatol,2002,19(1):1-8.
9JOLLY M, SEBIRE N, HARRIS J, et al. The risks associated with pregnancy in women aged 35 years or older[J]. Hum Reprod, 2000,15(11):2433-2437.
10SEOUD M A, NASSAR A H, USTA I M, et al. Increased risk of cesarean delivery with advancing maternal age: indications and associated factors in nulliparous women [J]. Am J Obstet Gynecol,2001,185(4):883-887.