8[5]Ong CY,Liao AW,Spencer K,et al.First trimester maternal serum free beta human chorionic gonadotrophin and pregnancy associated plasma protein A as predictors of pregnancy complications[J].BJOG,2000,107(10):1265-1267.
9[6]Merviel P,Muller F,Guibourdenche J,et al.Correlations between serum assays of human chorionic gonadotrophin(hCG) and human placental lactogen(hPL) and pre-eclampsia or intrauterine growth restriction(IUGR) among nulliparas younger than 38 years[J].Eur J Obstet Gynecol Reprod Biol,2001,95(1):59-61.
10[7]Lepage N,Chitayat D,Kingdom J,et al.Association between second-trimester isolated high maternal serum maternal serum human chorionic gonadotrophin levels and obstetic complications in singleton and twin pregnancies[J].Am J Obstet Gynecol,2003,188(5):1354-1356.
