Avtor/Urednik		Spencer, K; Souter, V; Tul, N; Snijders, R; Nicolaides, KH
Naslov		A screening program for trisomy 21 at 10-14 weeks using fetal nuchal translucency, maternal serum free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A
Tip		članek
Vir		Ultrasound Obstet Gynecol
Vol. in št.		Letnik 13
Leto izdaje		1999
Obseg		str. 231-7
Jezik		eng
Abstrakt		Objective. To examine the potential impact of combing maternal age with fetal nuchal translucency thickness and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in screening for trisomy 21 at 10-14 weeks of gestation. Methods. Maternal serum free beta-hCG and PAPP-A were measured by Jryptor, a random access immunoassay analyzer using time-resolved amplified cryptate emission, in 210 singleton pregnancies with trisomoy 21 and 946 chromosomally normal control, matched for maternal age, gestation and sample storage time. In all cases the fetal crown-rump lebgth and nuchal translucency thickness had been measured by ultrasonography at 10-14 weeks of gestation and maternal blood had been obtained at the time of the scan. The distributions (in multiples of the median; MoM) of free beta-hCG and PAPP-A (corrected for maternal weight) and fetal nuchal translucency (NT) were determined in the trisomy 21 group and the controls. Likelihood ratios for the trisomy 21 group and the controls. Likelihood ratios for the various marker combinations were calculated and these were used together with the age-related risk for trisomy 21 in the first trimester to calculate the expected detection rate of affected pregnancies, at a fixed false-positive rate, in a population with the maternal age distribution of pregnancies in England and Wales. Results. In a population with the maternal age distribution of pregnancies in England and Wales, it was estimated that, using the combination of maternal age, fetal nuchal translucency thickness and maternal serum free beta-hCG and PAPP-A, the detection of trisomy 21 pregnancies would be 89% at a fixed false-positive rate 5%. Alternatively, at a fixed detection rate of 70%, the false-positive rate would be 1%. The inclusion of biomechanical parameters added an additional 16% to the detection rate obtained using NT and maternal age alone. (Abstract truncated at 2000 characters).
Deskriptorji		DOWN SYNDROME PRENATAL DIAGNOSIS CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN FETAL DISEASES PREGNANCY-ASSOCIATED ALPHA-PLASMA PROTEIN PREGNANCY GESTATIONAL AGE LINEAR MODELS MASS SCREENING NECK PREGNANCY TRIMESTER, FIRST FALSE POSITIVE REACTIONS REFERENCE VALUES SENSITIVITY AND SPECIFICITY GREAT BRITAIN