Urine free beta-hCG and total estriol for Down syndrome screening during the second trimester in an Asian population.
OBJECTIVE
To evaluate second-trimester free beta-hCG and total estriol (E3) in the maternal urine as markers for Down syndrome screening in an Asian population.


METHODS
Free beta-hCG and total E3 were measured in the urine samples of 28 Taiwanese Down syndrome pregnancies and 268 unaffected singleton pregnancies at 14-25 weeks. Results were normalized to urine creatinine concentrations and converted to multiples of the median (MoM) levels. Gestational ages were estimated by ultrasound measurements.


RESULTS
Median values of free beta-hCG, total E3, free beta-hCG to total E3 ratio, and the free beta-hCG to total E3 MoM ratio in Down syndrome pregnancies were 4.75 MoM, 0.66 MoM, 8.99 MoM, and 9.51, respectively. At a 5% false-positive rate, the observed detection rates were 36% (ten of 28) with total E3, 71% (20 of 28) with free beta-hCG, 68% (19 of 28) with free beta-hCG/total E3, and 71% (20 of 28) with free beta-hCG/total E3 MoM. When combined with maternal age, the expected detection rates were 65% with total E3, 71% with free beta-hCG, 76% with free beta-hCG/total E3, 80% with free beta-hCG/total E3 MoM, and 89% when combining free beta-hCG, total E3, and maternal age.


CONCLUSIONS
Urine free beta-hCG and total E3 are useful markers for Down syndrome screening during the second trimester in Taiwanese women.
Hsu
J J
JJ
Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taiwan. jjhsu@ms6.hinet.net
Hsu
T Y
TY
Hsieh
T T
TT
Soong
Y K
YK
Hsieh
F J
FJ
Spencer
K
K
D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000652:urine*; D004314:Down Syndrome / Q000175:diagnosis*; D004964:Estriol / Q000652:urine*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis / Q000379:methods*; D013624:Taiwan
D018997:Chorionic Gonadotropin, beta Subunit, Human; D004964:Estriol