Dimeric inhibin A as a fourth marker for Down's syndrome maternal serum screening in native Japanese women.
OBJECTIVE
This study was conducted to assess the usefulness of dimeric inhibin A as a fourth marker for Down's syndrome screening in addition to AFP, hCG and uE3 markers for native Japanese women.


METHODS
Serum specimens from 367 native Japanese women in the second trimester were assayed for dimeric inhibin A levels. Day specific dimeric inhibin A medians were established for gestational ages 15.0-21.9. Weekly median values for the native Japanese were compared with those of a U.S. population. Selected Japanese specimens from 15 diagnosed Down's syndrome and 3 trisomy 18 cases were also assayed for dimeric inhibin A.


RESULTS
Dimeric inhibin A levels did not vary greatly over the gestational age range as expected. Median value comparison showed that native Japanese dimeric inhibin A medians are higher than the U.S. population medians by an average of 7.95%. Native Japanese dimeric inhibin A median values in this study are 1.77 times higher in Down's syndrome cases than in unaffected pregnancies. Trisomy 18 dimeric inhibin A levels show no significant difference from the unaffected pregnancies.


CONCLUSIONS
This report shows for the first time that dimeric inhibin A can be informative as a fourth marker for Down's syndrome screening in native Japanese women. We expect the addition of dimeric inhibin A to a triple marker protocol will increase the accuracy of predicted risk for all pregnancies screened and increase the detection rate of Down's syndrome affected pregnancies.
Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo, Japan.
K
K
Yoshida
Y
Y
Kuwabara
T
T
Tanaka
T
T
Onda
R
R
Kudo
H
H
Yamamoto
A
A
Sato
K
K
Yanagida
T
T
Okai
M
M
Sakai
Y
Y
Takai
H
H
Uemura
K
K
Hoshi
Y
Y
Fukada
T
T
Aono
K
K
Maeda
S
S
Ogita
O
O
Ishiko
Y
Y
Murata
T
T
Kanzaki
F
F
Myrick
R E
RE
Grier
D015415:Biomarkers / Q000097:blood*; D006063:Chorionic Gonadotropin / Q000097:blood; D002887:Chromosomes, Human, Pair 18; D019281:Dimerization; D004314:Down Syndrome / Q000097:blood* / Q000175:diagnosis*; D004964:Estriol / Q000097:blood; D005260:Female; D005865:Gestational Age; D006801:Humans; D007265:Inhibins / Q000097:blood*; D007564:Japan; D008423:Maternal Age; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011296:Prenatal Diagnosis; D014314:Trisomy; D000509:alpha-Fetoproteins / Q000032:analysis
D015415:Biomarkers; D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D007265:Inhibins; D004964:Estriol