-
Dose dependency between cigarette consumption and reduced maternal serum PAPP-A levels at 11-13(+6) weeks of gestation.
Kagan KO, Frisova V, Nicolaides KH, Spencer K.
Prenat Diagn 2007;27:849-53. -
Screening for trisomy 18 by fetal nuchal translucency and maternal serum free beta -hCG and PAPP-A at 10-14 weeks of gestation.
Tul N, Spencer K, Noble P, Chan C, Nicolaides K.
Prenat Diagn 1999;19:1035-42. -
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.
Spencer K, Souter V, Tul N, Snijders R, Nicolaides KH.
Ultrasound Obstet Gynecol 1999;13:231-7.