Normative Values of Second-Trimester Maternal Serum Markers Using an Automated Assay Platform for Down Syndrome Screening

Kusol Russameecharoen; Katika Nawapun; Buraya Phattanachindakun; Vitaya Titapant; Tuangsit Wataganara; Nisarat Phithakwatchara

doi:10.33192/Smj.2019.04

Normative Values of Second-Trimester Maternal Serum Markers Using an Automated Assay Platform for Down Syndrome Screening

Authors

Kusol Russameecharoen Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Katika Nawapun Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Buraya Phattanachindakun Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Vitaya Titapant Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Tuangsit Wataganara Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Nisarat Phithakwatchara Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.

DOI:

https://doi.org/10.33192/Smj.2019.04

Keywords:

Automated immunoassay; Down syndrome; maternal serum screening; quadruple test; reference values; second trimester

Abstract

Objective: Automated chemiluminescent immunoassay has several advantages over manual ELISA with comparable
test performance. Few studies have reported the reference values of the second-trimester serum markers maternal
serum alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3), and inhibin
A (Inh A) by automated immunoassay in Asian population. Accordingly, this study aimed to determine the
median values of second trimester serum markers as a function of gestational age (GA) in Thai population using
an automated immunoassay.
Methods: This prospective cross-sectional study of serum markers in healthy singleton second trimester (14-22
weeks) pregnant women was conducted at Siriraj Hospital from September 2012 to April 2015. Maternal serum
AFP, hCG, uE3, and Inh A were analyzed by automated immunoassay. Predicted median values as a function of
GA were calculated from best-fit regression equations.
Results: A total of 1,526 women were included. Median values serum markers were constructed from the following
optimal models: AFP (ng/mL) = 99.082 - 14.195 GA + 0.662 GA2, r2=0.995; hCG (mIU/mL) = 390168.106 - 35
968.397GA + 876.708GA2, r2=0.972; uE3 (ng/mL) = -3.388 + 0.274 GA, r2=0.997; and, Inh-A (pg/mL) = 1206.875 -
114.171 GA + 3.174 GA2, r2=0.882. Using the same platform analysis and maternal weight adjustment, the reference
values in Thai population were shown to be different from those of other ethnicities.
Conclusion: Median values of second-trimester serum markers for Thai population were determined. Maternal
weight and the use of population-specific normal values have to be taken into account for Down syndrome screening
in the second trimester.

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Published

15-02-2019

How to Cite

Russameecharoen, K., Nawapun, K., Phattanachindakun, B., Titapant, V., Wataganara, T., & Phithakwatchara, N. (2019). Normative Values of Second-Trimester Maternal Serum Markers Using an Automated Assay Platform for Down Syndrome Screening. Siriraj Medical Journal, 71(1), 21–24. https://doi.org/10.33192/Smj.2019.04

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Issue

Vol. 71 No. 1 (2019): January-February

Section

Original Article

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