Address of Corresponding Author

Fetal Diagn Ther 2006;21:140-143 (DOI: 10.1159/000089064)

  Key Words

• Biochemical markers
• Chinese
• First trimester
• Screening
• Trisomy 21

  Abstract

Objective: To study the effect of ethnic Chinese on the medians of free -hCG and PAPP-A in the first trimester of pregnancy. Methods: The data of 943 women undergoing first trimester combined screening for fetal Down syndrome were analysed to derive the Chinese-specific medians. The calculated risk of Down syndrome based on these Chinese-specific medians was compared with that based on the original algorithm of the Fetal Medicine Foundation (FMF). Results: The maternal serum levels of multiples of median of free -hCG and PAPP-A were significantly higher among the Chinese than among the Caucasians. The weight-adjusted gestation-specific medians were developed. Without adjustment for ethnicity, the original FMF algorithm underestimated the risk of Down syndrome by a median of 1%. Adjustment by ethnicity increased the false-positive rate by 10% (from 5.3 to 5.9%). Conclusion: Ethnic Chinese have a significantly higher maternal serum level of free -hCG and PAPP-A in the first trimester, which could not be explained by differences in maternal weight. Adjustment for ethnicity may be necessary for these biochemical markers in a first trimester screening program.

Copyright © 2006 S. Karger AG, Basel

  Author Contacts

Dr. Tze Kin Lau
Department of Obstetrics and Gynaecology
Prince of Wales Hospital
Shatin (Hong Kong)
Tel. +852 2632 2810, Fax +852 2636 0008, E-Mail tzekinlau@cuhk.edu.hk

  Article Information

Received: October 15, 2004
Accepted after revision: January 26, 2005
Number of Print Pages : 4
Number of Figures : 0, Number of Tables : 1, Number of References : 13