Authors: Spencer, K Tul, N Nicolaides, KH

Citation: K. Spencer et al., Maternal serum free beta-hCG and PAPP-A in fetal sex chromosome defects inthe first trimester, PRENAT DIAG, 20(5), 2000, pp. 390-394

Authors: Spencer, K Souter, V Tul, N Snijders, R Nicolaides, KH

Citation: K. Spencer et al., 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, ULTRASOUN O, 13(4), 1999, pp. 231-237

Authors: Tul, N Spencer, K Noble, P Chan, C Nicolaides, K

Citation: N. Tul et al., Screening for trisomy 18 by fetal nuchal translucency and maternal serum free beta-hCG and PAPP-A at 10-14 weeks of gestation, PRENAT DIAG, 19(11), 1999, pp. 1035-1042