Efficacy of maternal serum screening in the prenatal detection of fetal chromosome abnormalities in Japanese women.
OBJECTIVE
This prospective study assesses the efficacy of maternal serum screening for use in prenatal diagnosis of fetal anomaly and chromosome imbalance in Japanese women.


METHODS
Maternal serum alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol were measured in 1,055 singleton pregnant women between 14 and 20 weeks of gestation. A calculated risk for trisomy 21 of >/=1/299 or alpha-fetoprotein >/=2.5 multiples of the median was adopted as positive.


RESULTS
Three hundred and seventy-eight of the 1, 055 women screened (35.8%) were identified as positive. Sensitivity, false-positive rate, and positive predictive value in women aged <35 years were 60.0, 10.6, and 6.8%, respectively, and these values were 87.5, 49.3, and 4.2%, respectively, in women aged >/=35 years. The false-positive rate in women aged <35 years was significantly lower than that for women aged >/=35 years (p < 0.001). Chromosomal abnormalities were identified in 21 cases, including 10 with trisomy 21, 5 with trisomy 18, 2 with trisomy 13, and 4 with other chromosomal disorders. Seventeen of the 21 cases (81.0%) showed screen-positive results, and among these all 10 cases with trisomy 21 were detectable. Two cases with trisomy 18, 1 with trisomy 13 and 1 with isochromosome X showed extremely low human chorionic gonadotropin levels (0.4 +/- 0.1 multiples of the median, mean +/- SE), although they were screen negative. Of the 264 women who did not undergo amniocentesis, none had any clinical findings consistent with aneuploidy after birth.


CONCLUSIONS
Our results suggest that the evaluation of each serum marker, as well as of the calculated risk, was significantly important in the prenatal detection of fetal aneuploidy.
Kishida
T
T
Department of Obstetrics and Gynecology, Hokkaido University School of Medicine, Sapporo, Japan. tatsuro@med.hokudai.ac.jp
Hoshi
N
N
Hattori
R
R
Negishi
H
H
Yamada
H
H
Okuyama
K
K
Hanatani
K
K
Takagi
T
T
Sagawa
T
T
Fujimoto
S
S
D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood*; D002869:Chromosome Aberrations; D002882:Chromosomes, Human, Pair 13; D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000175:diagnosis; D004964:Estriol / Q000097:blood*; D005189:False Positive Reactions; D005260:Female; D005865:Gestational Age; D006801:Humans; D007564:Japan; D008423:Maternal Age; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014314:Trisomy; D000509:alpha-Fetoproteins / Q000032:analysis*
D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D004964:Estriol