title: Urine free beta-hCG and total estriol for Down syndrome screening during the second trimester in an Asian population.
abstract: OBJECTIVE
  To evaluate second-trimester free beta-hCG and total estriol (E3) in the maternal urine as markers for Down syndrome screening in an Asian population.
  
  
  METHODS
  Free beta-hCG and total E3 were measured in the urine samples of 28 Taiwanese Down syndrome pregnancies and 268 unaffected singleton pregnancies at 14-25 weeks. Results were normalized to urine creatinine concentrations and converted to multiples of the median (MoM) levels. Gestational ages were estimated by ultrasound measurements.
  
  
  RESULTS
  Median values of free beta-hCG, total E3, free beta-hCG to total E3 ratio, and the free beta-hCG to total E3 MoM ratio in Down syndrome pregnancies were 4.75 MoM, 0.66 MoM, 8.99 MoM, and 9.51, respectively. At a 5% false-positive rate, the observed detection rates were 36% (ten of 28) with total E3, 71% (20 of 28) with free beta-hCG, 68% (19 of 28) with free beta-hCG/total E3, and 71% (20 of 28) with free beta-hCG/total E3 MoM. When combined with maternal age, the expected detection rates were 65% with total E3, 71% with free beta-hCG, 76% with free beta-hCG/total E3, 80% with free beta-hCG/total E3 MoM, and 89% when combining free beta-hCG, total E3, and maternal age.
  
  
  CONCLUSIONS
  Urine free beta-hCG and total E3 are useful markers for Down syndrome screening during the second trimester in Taiwanese women.
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taiwan. jjhsu@ms6.hinet.net
authors.forename: J J
authors.initials: JJ
authors.lastname: Hsu
authors.forename: T Y
authors.initials: TY
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: F J
authors.initials: FJ
authors.lastname: Hsieh
authors.forename: K
authors.initials: K
authors.lastname: Spencer
mesh_terms: D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000652:urine*; D004314:Down Syndrome / Q000175:diagnosis*; D004964:Estriol / Q000652:urine*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis / Q000379:methods*; D013624:Taiwan
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D004964:Estriol