Objective To study prospectively the use of maternal serum alpha fetoprotein (AFP) and total β human chorionic gonadotropin (hCG) concentrations for screening of Down syndrome in Hong Kong.Methods AFP and total ...Objective To study prospectively the use of maternal serum alpha fetoprotein (AFP) and total β human chorionic gonadotropin (hCG) concentrations for screening of Down syndrome in Hong Kong.Methods AFP and total β hCG were measured in serum samples from 1638 singleton Chinese pregnancies at 14-22 weeks of gestation, recruited over a twelve month period. Gestational ages were determined by ultrasonographic parameters measured at the same visit as the test for all cases. The gestational age specific and weight adjusted medians for serum AFP and total β hCG were calculated. Risk for fetal Down syndrome (FDS) was derived by mathematical modeling of the medians together with maternal age. Amniocenteses were offered to women with a calculated FDS risk of 1∶270 or greater.Results The gestational age specific and weight adjusted medians for maternal serum AFP were similar to previous studies while that of total β hCG were higher. A total of 101 patients (6.1%) were classified as being high risk for FDS, including 3.4% (48/1394) of those younger than 35 years of age and 21.7% (53/244) of those who were 35 or above. There were 4 cases of Down syndrome, 1 case of Turner syndrome and 1 of Edward syndrome. Three out of the four cases of Down syndrome were screened positive, corresponding to a detection rate of FDS of 75%. A case of Turner syndrome was also screened positive. A case of trisomy 18 was found to have very low levels of AFP [0.262 multiple of median (MoM)] and total β hCG (0.115 MoM).Conclusions Maternal serum screening using double biochemical markers (AFP and total β hCG) in combination with gestational dating by ultrasonography is effective in the detection of fetal Down syndrome and possibly other chromosomal disorders in Chinese pregnant women.展开更多
文摘Objective To study prospectively the use of maternal serum alpha fetoprotein (AFP) and total β human chorionic gonadotropin (hCG) concentrations for screening of Down syndrome in Hong Kong.Methods AFP and total β hCG were measured in serum samples from 1638 singleton Chinese pregnancies at 14-22 weeks of gestation, recruited over a twelve month period. Gestational ages were determined by ultrasonographic parameters measured at the same visit as the test for all cases. The gestational age specific and weight adjusted medians for serum AFP and total β hCG were calculated. Risk for fetal Down syndrome (FDS) was derived by mathematical modeling of the medians together with maternal age. Amniocenteses were offered to women with a calculated FDS risk of 1∶270 or greater.Results The gestational age specific and weight adjusted medians for maternal serum AFP were similar to previous studies while that of total β hCG were higher. A total of 101 patients (6.1%) were classified as being high risk for FDS, including 3.4% (48/1394) of those younger than 35 years of age and 21.7% (53/244) of those who were 35 or above. There were 4 cases of Down syndrome, 1 case of Turner syndrome and 1 of Edward syndrome. Three out of the four cases of Down syndrome were screened positive, corresponding to a detection rate of FDS of 75%. A case of Turner syndrome was also screened positive. A case of trisomy 18 was found to have very low levels of AFP [0.262 multiple of median (MoM)] and total β hCG (0.115 MoM).Conclusions Maternal serum screening using double biochemical markers (AFP and total β hCG) in combination with gestational dating by ultrasonography is effective in the detection of fetal Down syndrome and possibly other chromosomal disorders in Chinese pregnant women.
