Maternal weight and ethnic adjustment within a first-trimester Down syndrome and trisomy 18 screening program.

Autor: Krantz, David A., Hallahan, Terrence W., Macri, V. James, Macri, James N.
Zdroj: Prenatal Diagnosis; Aug2005, Vol. 25 Issue 8, p635-640, 6p
Abstrakt: Objective(s) To estimate weight and ethnic group correction factors for first-trimester screening markers. Methods Ethnic-specific median MoM free beta hCG and pregnancy associated plasma protein A (PAPP-A) and delta nuchal translucency values were calculated for cohorts of maternal weight (20 lb each) using data from 51 206 patients undergoing first-trimester screening. False-positive rates for Down syndrome and trisomy 18 were evaluated both prior to and after weight and ethnicity adjustment. Results Free beta hCG and PAPP-A significantly decreased with increasing maternal weight while nuchal translucency increased by a clinically insignificant amount. For free beta hCG the regression formula indicated that after accounting for maternal weight MoM values were 16% higher for African Americans, 6% higher for Asians and 9% lower for Hispanics compared to Caucasians ( p < 0.001, p = 0.001, p < 0.001, respectively) but there was no significant difference for Asian Indians. For PAPP-A, MoM values were 35% higher for African Americans ( p < 0.001) but were not significantly different for the other ethnic groups compared to Caucasians. Down syndrome false-positive rates did not vary with maternal weight prior to ( p = 0.291) or after weight adjustment of biochemistry ( p = 0.054). Trisomy 18 false-positive rates varied significantly with weight both before (OR = 1.455 per 20-pound increase, p < 0.001) and after (OR = 1.066 per 20-pound increase, p = 0.01) weight adjustment of biochemistry; however, the odds ratio was greatly reduced after weight adjustment. Conclusion(s) The first-trimester screening markers, free beta hCG, PAPP-A and nuchal translucency vary with maternal weight and ethnicity. Adjustment of free beta hCG and PAPP-A is indicated but adjustment of nuchal translucency results may not be necessary. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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