1De Leon J, Sifuentes G, Hopkins C, et al. Maternal serum flee beta- HCG levels in uncomplicated pregnancies at the 10th-15th week of gestation and the development of cbstetrlc complications [J]. J Reprod Med, 2004, 49 (2): 89-92.
2Brajenovic-Milic B, Trislaric D, Zuvic-Butorac M, et al. Elevated Second-Trimeste-r Free β-HCG as an Isolated Finding and Pregnancy Outcomes [J]. Fetal Diagn Ther, 2004, 19 (6) : 483 - 487.
3Yuval Yaron. Second-trlmester maternal serum marker screening: Matem screening: Maternal serum α-fetoprotein, β-human chorionic gonadotropin, estriol, and their various combinations as predictors of pregnancy outcome [J]. Am J Obstet Gynecol, 1999, 181 (4): 968 - 974.
4L. S . Onderoglu, A Kabukeu. Elevated second trimester human ehorionic gonadotropin level associated with adverse pregancy outcome [J]. International journal of Gynecology Obstetrics, 1997, 56:245 - 249.
5R Gonen. The Association Between Unexplained Second-Trimester Maternal Serum hCG Elevation and Pregnancy Complications [ J ]. Obstetric and Gynecology, 1992, 80 (1): 83-85.
6Lepage N, Chitayat D, Kingdom J, etal. Association between secondtrimester isolated high maternal serum maternal serum human chorionic gonadotropin levels and cbstetric complications in singleton and twin pregnancies [J]. Am J Obstet Gynecol, 2003, 188 (5): 1354 - 1359.
7Chandra S, Scott H, Dodds L, et al. Unexplained elevated matenal serum alpha-fetroprtein and/or human chofionic gonadotropin and the risk of adverse outcomes [ J]. Am J Obstet Gynecol, 2003, 189 (3) : 775-781.
8Annaleena H, Nonna M. Elevater raatemal serum hCG in the second trimester increases prematurity rote and need for neonatal intensive care primip -arous preeclamptic pregnancies [ J ]. Hypertension in Pregnancy, 2001, 20 (1): 99-106.
9peter A, Jonathan M. Elevated Second-Trimester Maternal Serum hCG Alone or in Combination With Elevated Alpha-Fetopr otein [ J ]. February, 1996, 87 (2): 217-222.
10Lieppman RE, Williams M. A. An association between debated levels of human chorionic gonadotropin in the midtrimester and adverse pregnancy outcome [ J ]. Am J Obstet Gynecol, 1993, 168 (6) : 1852- 1857.
