title: Comparison of Down's syndrome screening strategies in Asians combining serum free beta-hCG and alpha-fetoprotein with maternal age.
abstract: High free beta human chorionic gonadotropin (beta-hCG) and low alpha-fetoprotein (AFP) levels were found in 47 Asian Down's syndrome pregnancies (median values 2.79 and 0.77 MOM, respectively). At a 5 per cent false-positive rate, free beta-hCG alone would identify 46.8 per cent of Down's syndrome pregnancies, age alone detected 34.5 per cent of affected cases, whilst AFP alone detected 17 per cent and free beta-hCG/AFP MOM ratios detected 48.9 per cent of Down's syndrome cases. When combined with maternal age-specific risk, free beta-hCG could achieve a 59.6 per cent detection rate, with AFP achieving 42.6 per cent, free beta-hCG/AFP MOM ratios 61.7 per cent, and combined free beta-hCG and AFP a detection rate of 63.8 per cent for a 5 per cent false-positive rate. Down's syndrome screening at an early gestational age (before 18 weeks) could achieve a 68 per cent detection rate with a 5 per cent false-positive rate, compared with a 59.1 per cent detection rate for a 5.2 per cent false-positive rate when screening at a late gestational age. The use of free beta-hCG in Down's syndrome screening programmes can yield an improved efficacy in the detection of Down's syndrome in an Asian population.
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taiwan, Republic of China.
authors.forename: J J
authors.initials: JJ
authors.lastname: Hsu
authors.forename: T T
authors.initials: TT
authors.lastname: Hsieh
authors.forename: Y K
authors.initials: YK
authors.lastname: Soong
authors.forename: K
authors.initials: K
authors.lastname: Spencer
mesh_terms: D000293:Adolescent; D000328:Adult; D002681:China / Q000208:ethnology; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008423:Maternal Age; D011114:Polynesia / Q000208:ethnology; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011296:Prenatal Diagnosis / Q000379:methods*; D013624:Taiwan; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D000509:alpha-Fetoproteins