6Monig H, Hensen J, Lehnert H. Thyroid disorders and pregnancy[J]. Internist(Berl) ,2010,51(5) :620.
7Van Beynum IM,Kapusta L,Bakker MK,et al. Protective effect of periconceptional folic acid supplements on the risk of congenital heart de{ects:a registry-based case con- trol study in the northern Netherlands[J]. Eur Heart J, 2010,31,(4):464-471.
9van der Linde D,Konings EE,Slager MA,et al.Birth prevalence of congenital heart disease worldwide:a systematic review and meta-analysis[J].J Am Coll Cardiol,2011,58(21):2241-2247.
10Chadha SL,Singh N,Shukla DK.Epidemiological study of congenital heart disease[J].Indian J Pediatr,2001,68(6):507-510.