1Kliegman R M, Behrman R E, Jenson H B, et al. Nelson Textbook of Pediatrics[M]. 18th edition. Philadelphia: Saunders Elsevier, 2007 : 699-700.
2Blonde! B. Increase in twin maternities and consequences on health[J]. J Gynecol Obstet Biol Reprocl, 2009,38 : 7-17.
3Blondel B, Kaminski M. The increase in multiple births and its consequences on perinatal health[J]. J Gynecol Obstet Biol Reprod (Paris) ,2002 ,31: 725-740.
4曹泽毅.中华妇产科学[M].2版.北京:人民卫生出版社,2004:2163-2169.
5Sun H C, Young SP, Kye SS, et al. Recent trends in the incidence of multiple births and its consequences on perinatal problems in Korea[J]. J Korean Med Sci,2010, 25:1191-1196.
6Deshayne B F, Joseph K S. Temporal trends in the fre- quency of twins and higher-order multiple births in Cana- da and the United States[J]. BMC Pregnancy Childbirth, 2012, 27(12) :103-109.
7Gan J P, Wu Z H, Tu Z M, et al. The comparison of twinning rates between urban and rural areas in China [J]. Twin Res Hum Genet,2007,10(4) :633-637.
8Hack K E A, Derks J B, Elias S G, et al. Perinatal mor- tality and mode of delivery in monochorionic diamniotie twin pregnancies ≥32 weeks of gestation: a muhicentre retrospective cohort study[J]. BJOG: An International lournal of Obstetrics and Gynaeeology, 2011, 118 (9): 1090-1097.
9Jodie M D, Caroline A C, Ross R H,et al. Timing of birth for women with a twin pregnancy at term: a ran- domised controlled trial[J]. BMC Pregnancy Childbirth, 2010,10 : 68-73.
2Boyer A, Cameron L, Maldonado YM, et al. Clinical significance of am- niotic fluid sludge in twin pregnancies with a short cervical length[ J]. American Journal of Obstetrics and Gynecology, 2014,211 ( 5 ) : 506- 506.
3Geisler ME, Mahony A, Meaney S, et al. Obstetric and perinatal out- comes of twin pregnancies conceived following IVF/ICSI treatment compared with spontaneously conceived twin pregnancies [ J ]. Euro- pean Journal of Obstetrics & Gynecology and Reproductive Biology, 2014,181 (132) :78-83.