Medians for second-trimester maternal serum α-fetoprotein, human chorionic gonadotropin, and unconjugated estriol; differences between races or ethnic groups

Abstract

Second-trimester maternal serum α-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) are routinely measured in screening fetuses at high risk for Down syndrome or open neural tube defects (ONTD). For test interpretation, individual patient values of these three analytes are related to population-derived median values. We evaluated data from >21 000 pregnancies to determine the extent of race-specific differences in median concentrations. For samples at most gestational ages, median AFP, hCG, and uE3 values for white, black, Hispanic, and other patients were all significantly different. Differences remained significant even when data were corrected for patient weights. For each analyte, the extent of the variation was not the same at different gestational ages. Differences in median values across race/ethnicity groups appear to have only a small impact in Down syndrome screening but it may be appropriate to use alternative sets of AFP medians or adjustment factors to AFP medians for some Asian populations receiving ONTD screening.

Second‐trimester double or triple screening for Down syndrome: A comparison of Chinese and Caucasian populations

“…It has been reported that serum levels of AFP, hCG, and uE3 were higher in Oriental than in Caucasian women [16–18]. In the present study, the medians of serum marker levels calculated at relevant GAs for the unaffected group were compared with published values for Caucasian women with unaffected pregnancies [12].…”

Different median levels of serum triple markers in the second trimester of pregnancy in a Thai Ethnic Group

“…The medians of AFP, free b-hCG and uE3 for each gestational weeks (from [14][15][16][17][18][19][20] were calculated, and regression modeling was performed to obtain the best fitted equation for predicted medians as a function of gestational age. Maternal weight adjustment was performed as previously described, 16,17 either log-linear or reciprocal-linear correction depending on the highest correlation coefficients.…”

“…The uE3 concentrations have been reported to be similar in samples of European and African descent, but have not been reported for Asians. 8 Benn et al 19 postulated that the marked differences observed in the various studies may probably be attributable to the inconsistent use of maternal weight correction, maternal age differences, heterogeneity in the gestational ages of the screened populations, and regional differences in the subpopulations of women included in each group. For the effective use of triple screens, all of these factors needed to be controlled.…”

Prediction and prevention of pre‐eclampsia in Asian subpopulation

“…There is a significant ethnic variation in serum levels of the placental‐derived analytes. Therefore, the development of multimarker screening requires an establishment of population‐specific MoM and regression algorithm . The racial‐associated variations may be from genetic, dietary or lifestyle differences .…”