Taiwanese Journal of Obstetrics and Gynecology
Volume 46, Issue 3 , Pages 230-235, September 2007

Total hCG Versus Free β-hCG Combined with Alpha-fetoprotein for Down Syndrome Screening in Taiwan

  • Tsang-Tang Hsieh

      Affiliations

    • Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Taipei, Taiwan
    • ,
  • Jenn-Jeih Hsu

      Affiliations

    • Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Taipei, Taiwan
    • Corresponding Author InformationCorrespondence to: Dr Jenn-Jeih Hsu, Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Chang Gung University, 199, Tung-Hwa North Road, Taipei, Taiwan
    • ,
  • Po-Jen Cheng

      Affiliations

    • Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Linkou, Taiwan
    • ,
  • Chien-Nan Lee

      Affiliations

    • Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan
    • ,
  • Hei-Jen Jou

      Affiliations

    • Department of Obstetrics and Gynecology, Taiwan Adventist Hospital, Taipei, Taiwan
    • ,
  • Chih-Ping Chen

      Affiliations

    • Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan

Accepted 26 September 2006.

Article Outline

Summary 

Objective

The purpose of this study was to compare the effectiveness between total human chorionic gonadotropin (hCG) and free β-hCG in two-marker Down syndrome screening programs during the second trimester in a Taiwanese population.

Materials and Methods

From a multicenter collaborative study, we investigated the second-trimester maternal serum levels of total hCG from 67 data, free β-hCG from 72 and alpha-fetoprotein (AFP) from 96 obtained from Taiwanese pregnant women carrying fetuses with Down syndrome.

Results

High total hCG and free β-hCG, as well as low AFP levels, were found with median values of 2.06, 2.49 and 0.77 multiples of the median (MoM), respectively. At a 5% false-positive rate, total hCG and free β-hCG could detect 31% and 43% of Down syndrome pregnancies, respectively, whilst AFP alone could detect only 15% of affected cases. When combined with maternal age-specific risk, total hCG could achieve a 52% detection rate, free β-hCG a 54% and AFP a 39%. Combined total hCG and AFP achieved a detection rate of 55%, and combined free β-hCG and AFP achieved a rate of 60%.

Conclusion

The measurement of free β-hCG is more beneficial than total hCG in serum screening for Down syndrome during the second trimester of pregnancy.

Key Words:  AFP , Asians , Down syndrome screening , free β-hCG , total hCG

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PII: S1028-4559(08)60025-X

doi:10.1016/S1028-4559(08)60025-X

Taiwanese Journal of Obstetrics and Gynecology
Volume 46, Issue 3 , Pages 230-235, September 2007

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