4World Health Organization. Global registry and database on craniofacial anomalies. [ 2009 -06 - 13 ]. http://whqlibdoc. who. int/publications/2003/9241591102. pdf.
5李竹,钱宇平.出生缺陷监测.第1版.北京:人民卫生出版社,1994:1.
6Solomon LB, Rtlhli FJ, Lee YC, et al. Secular trend in the opening of the sacral canal: an Australian study. Spine ,2009,34 (3) :244.
7Hosain GM, Chatterjee N, Begun A, et al. Factors associated with low birth weight in rural Bangladesh. J Trop Pediatr, 2006,52 ( 2 ) 87 - 91.
8Ricketts SA, Murray EK, Schwalberg R, et al. Reducing low birth weight by resolving risks:Results from Colorado~ Prenatal Plus Program, Am J Public Health, 2005,95 ( 11 ) : 1952 - 1957.
10Wilson RD, Davies G, Desilets V, et al. The use of folic acid for the prevention of neural tube defects and other congenital anomalies. J Obstet Gynaecol Can ,2003,25 ( 1 ) :959.