Wenstrom K D, Desai R, Owen J, DuBard M B, Boots L
Department of Obstetrics and Gynecology, University of Alabama at Birmingham 35233-7333, USA.
Am J Obstet Gynecol. 1995 Oct;173(4):1287-92. doi: 10.1016/0002-9378(95)91372-6.
Our purpose was to compare the multiple-marker screening test with elective amniocentesis for the detection of fetal Down syndrome and other aneuploidies in women aged > or = 35.
Our database included the multiple-marker screening test (maternal serum alpha-fetoprotein, human chorionic gonadotropin, unconjugated estriol, and maternal age) and genetic amniocentesis results from 1942 women aged > or = 35. A Down syndrome risk > or = 1:190 was considered screen positive. An algorithm to detect trisomy 18 was also used.
The multiple-marker screening test Down syndrome screen-positive rate was 26.1% (507/1942). The Down syndrome detection rate was 75% (33/44); the trisomy 18 detection rate was 75% (3/4). However, the multiple-marker screening test detection rate for all aneuploidies was only 61%. Missed aneuploidies included trisomy 21, sex chromosome abnormalities, trisomy 13, trisomy 22, and trisomy 18.
The multiple-marker screening test fails to detect approximately 39% of all fetal aneuploidies in women aged > or = 35. These data should be provided to women considering prenatal diagnosis so that they can make an informed decision regarding the multiple-marker screening test versus amniocentesis for advanced maternal age.
