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Different median levels of serum triple markers in the second trimester of pregnancy in a Thai Ethnic Group
Author(s) -
Wanapirak Chanane,
Sirichotiyakul Supatra,
Luewan Suchaya,
Yanase Yuri,
Traisrisilp Kuntharee,
Tongsong Theera
Publication year - 2012
Publication title -
journal of obstetrics and gynaecology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 50
eISSN - 1447-0756
pISSN - 1341-8076
DOI - 10.1111/j.1447-0756.2011.01769.x
Subject(s) - medicine , obstetrics , gestational age , estriol , gestation , reference range , pregnancy , second trimester , human chorionic gonadotropin , alpha fetoprotein , fetus , triple test , gynecology , hormone , biology , genetics , hepatocellular carcinoma
Aim: The aim of the present study was to establish Thai‐specific reference ranges of triple markers for fetal Down syndrome as a function of gestational age as well as weight correction models and to compare the false positive rates when using Thai‐specific model relative to Caucasian‐specific model. Material and Methods: A total of 993 normal Thai pregnant women were determined for mid‐trimester serum levels of alpha‐fetoprotein (AFP), free‐beta human chorionic gonadotropin (hCG), and unconjugated estriol (uE3), using DefiaXpress system (Perkin Elmer, Waltham, MA, USA). Results: The models of Thai‐specific medians for AFP, b‐hCG, and uE3, as well as the models for weight correction were derived and the normal reference ranges were constructed. The best fitted equation for AFP, b‐hCG and uE3 are as follows: predicted median = 2.675 × 10 (0.153 × GA in week) , r = 0.979; 10 (−0.717 + 57.487/GA in week) , r = 0.991; and 10 (5.678–69.346/GA in week) , r = 0.997, respectively. The models were properly applied to another group of 302 Thai women, signifying that they were reliable models. The weight‐adjusted gestation‐specific medians derived from Caucasian models were significantly higher than those based on Thai models and the false positive rate could be reduced from 10 to 7.1% when Thai models were applied. Conclusion: Thai reference ranges of triple screen markers as a function of gestational age as well as weight correction models have been established. The Caucasian reference range, even after weight correction, gives a positive rate that is much higher than that it should be, strongly suggesting the need for ethnicity‐specific medians.