First-trimester aneuploidy screening using serum human chorionic gonadotropin (hCG), free ahCG, and progesterone.
Immunochemical serum assays for human chorionic gonadotropin (hCG), the free ahCG subunit, and progesterone (P) were considered separately and in combination for their ability to screen for chromosomally abnormal pregnancies in the first trimester. Maternal serum was collected from 141 women undergoing chorionic villus sampling at 9-12 menstrual weeks. Trisomy 21 pregnancies had significantly higher hCG levels, while trisomy 18 and 13 pregnancies had markedly lower hCG and progesterone levels than those of chromosomally normal pregnancies. However, the discrimination of normal from aneuploid pregnancies was poor with either hCG alone, progesterone alone, or free ahCG alone. Much improved discrimination was obtained by combining hCG, free ahCG, and P into an aneuploidy index [(P/hCG)(free ahCG/hCG)]. This index distinguished 9 out of 17 (53 per cent) of the trisomy 21 pregnancies, while only misidentifying 5 out of 112 (4.5 per cent) of the normal pregnancies. The aneuploidy index thus appears promising as a first-trimester biochemical screen for aneuploid pregnancies.
Kratzer
P G
PG
Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco 94143-0132.
Golbus
M S
MS
Monroe
S E
SE
Finkelstein
D E
DE
Taylor
R N
RN
D000782:Aneuploidy; D006063:Chorionic Gonadotropin / Q000097:blood*; D002869:Chromosome Aberrations / Q000175:diagnosis*; D025063:Chromosome Disorders; D002885:Chromosomes, Human, Pair 16; D002887:Chromosomes, Human, Pair 18; D002892:Chromosomes, Human, Pair 22; D002893:Chromosomes, Human, Pair 3; D004314:Down Syndrome / Q000175:diagnosis; D005260:Female; D015292:Glycoprotein Hormones, alpha Subunit / Q000097:blood*; D006801:Humans; D011247:Pregnancy / Q000097:blood*; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011374:Progesterone / Q000097:blood; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D012189:Retrospective Studies
D006063:Chorionic Gonadotropin; D015292:Glycoprotein Hormones, alpha Subunit; D011374:Progesterone