2Blickstein I,Keith LG.Outcome of triplets and high-order multiple pregnancies.Curr Opin Obstet Gynecol,2003,15:1
二级参考文献4
1曹泽毅.中华妇产科学（第1版）[M].北京:人民卫生出版社,1999.35-37.
2Wilcox LS, Kiely JL, Melvin CL, et al. Assisted reproductive technologies: estimates of their contribution to multiple births and newborn hospital days in the United States. Fertil Steril, 1996,65:361-366.
3Daniel Y, Ochshorn Y, Fait G, et al. Analysis of 104 twin pregnancies conceived with assisted reproductive technologies and 193 spontaneously conceived twin pregnancies. Fertil Steril, 2000,74:683-689.
