Use of ethnic-specific medians for Hispanic patients reduces ethnic disparities in multiple marker screening.
OBJECTIVE
To estimate whether midtrimester maternal serum analyte concentrations differ between Caucasian and Hispanic women and whether using ethnic-specific medians affects quad screen performance.


METHODS
Caucasian and Hispanic patients with singletons who underwent maternal serum screening in our laboratory were identified. Alfa-fetoprotein (AFP), estriol, human chorionic gonadotrophin (hCG), and inhibin-A medians were derived separately for Caucasians, Hispanics, and for the composite group. Using composite medians, intergroup mean multiples of the medians (MoMs) for each analyte were compared. Using ethnic-specific medians, new MoMs were calculated and utilized in a risk estimation algorithm.


RESULTS
A total of 5478 Caucasian and 2246 Hispanic pregnancies were evaluated. Intergroup MoMs were significantly different for all analytes. AFP, hCG, and inhibin-A were lower in Hispanics, while estriol was higher (P < 0.0001). Using composite medians, the screen-positive rate (SPR) for trisomy 21 was 5.39% in Caucasians and 3.29% in Hispanics. Ethnic-specific medians reduced this disparity: 4.76% in Caucasians and 4.05% in Hispanics. The SPR for neural tube defects with composite medians was 1.44% for Caucasians and 0.89% for Hispanics; with ethnic-specific medians, the SPR was 1.42% for Caucasians and 1.07% for Hispanics.


CONCLUSIONS
Serum analyte concentrations differ between Caucasian and Hispanic gravidas. Use of ethnic-specific medians reduces the disparity in SPR for trisomy 21 and neural tube defects.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL 35249, USA. Luisa.Wetta@obgyn.uab.edu
Luisa
L
Wetta
Joseph
J
Biggio
John
J
Owen
D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood*; D006063:Chorionic Gonadotropin / Q000032:analysis / Q000097:blood; D004964:Estriol / Q000032:analysis / Q000097:blood; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D054625:Healthcare Disparities / Q000208:ethnology* / Q000706:statistics & numerical data; D006801:Humans; D007265:Inhibins / Q000032:analysis / Q000097:blood; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood; D011262:Pregnancy Trimester, Second / Q000097:blood; D011296:Prenatal Diagnosis / Q000379:methods / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D055815:Young Adult; D000509:alpha-Fetoproteins / Q000032:analysis
D015415:Biomarkers; D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; C422362:inhibin A; D007265:Inhibins; D004964:Estriol