Abstract: Objective：To examine maternal serum concentrations of leptin，beta-human chorionic gonadotropin（β-hCG） and ADAM12 between second and third trimester of pregnancy， and investigate whether an appropriate combination of those markers may be an effective means of screening for preeclampsia（PE）. Methods：Samples from 189 pregnant women who presented to Fujian Maternity and Child Health Hospital for prenatal care from June 2007 to May 2008 were included in this prospective study，of which 25 were subsequently developed PE as case group and 164 were normal pregnant women as control group. The maternal serum was conducted between their second（between 20th to 24th week of pregnancy） and third（between 30th to 34th week of pregnancy） trimester of pregnancy. The cutoff point was determined using a receiver operating characteristic curve. Results：①The second trimester level of serum β-hCG and ADAM12 in case group were significantly higher than normal group（P＜0.001）. ②The third trimester level of serum leptin，β-hCG and ADAM12 in case group were significantly higher than normal group （P＜0.001）. ③ The third trimester level of serum leptin，β-hCG and ADAM12 in case group were significantly higher than their second trimester level（P＜0.05）. The third trimester level of serum leptin in normal group was significantly higher than their second trimester level （P＜0.001）. ④The cutoff concentration of β-hCG was 32 μg/L and ADAM12 was 818 μg/L in second trimester of pregnancies. Combining the values of β-hCG and ADAM12 to form a screening test would detect an estimated 82.61% of affected pregnancies. There was no statistically significant difference between combining β-hCG and ADAM12 AUC and single β-hCG or ADAM12 AUC（P＞0.05）.⑤The cutoff concentration of leptin was 23 μg/L， β-hCG was 37 μg/L and ADAM12 was 900 μg/L in the third trimester of pregnancies. Combining the values of leptin，β-hCG and ADAM12 to form a screening test would detect an estimated 92.31% of affected pregnancies. AUC of combined leptin，β-hCG and ADAM12 is greater than the single leptin or β-hCG leptin（P＜0.05）, but there was no statistically significant difference between combined leptin，β-hCG and ADAM12 and single ADAM12 （P＜0.05）.⑥Combining the second and third trimester levels of serum β-hCG to form a screening test would detect an estimated 81.25% of affected pregnancies. Combining the second and third trimester levels of maternal serum ADAM12 to form a screening test would detect an estimated 90.48% of affected pregnancies. Conclusions：This study shows that measuring levels of β-hCG and ADAM12 during the second and third trimester of pregnancy are useful in clinical practice to identify pregnant women who will develop preeclampsia.

Key words: Pre-eclampsia, Leptin, Chorionic gonadoｔｒｏｐｉｎ, ｂｅｔａ ｓｕｂｕｎｉｔ, ｈuman, Pregnancy trimesteｒ, Pregnancy trimesteｒ, ｔｈird