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A reassessment of biochemical marker distributions in trisomy 21-affected and unaffected twin pregnancies in the first trimester.
Madsen HN, Ball S, Wright D, Tørring N, Petersen OB, Nicolaides KH, Spencer K.
Ultrasound Obstet Gynecol 2011;37:38-47. -
Screening for trisomy 21 in twin pregnancies in the first trimester: an update of the impact of chorionicity on maternal serum markers.
Spencer K, Kagan KO, Nicolaides KH.
Prenat Diagn 2008;28:49-52. -
Screening for trisomy 21 in twins using first trimester ultrasound and maternal serum biochemistry in a one-stop clinic: a review of three years experience.
Spencer K, Nicolaides KH.
BJOG 2003;110:276-80. -
First trimester prenatal diagnosis of trisomy 21 in discordant twins using fetal nuchal translucency thickness and maternal serum free beta-hCG and PAPP-A.
Spencer K, Nicolaides KH.
Prenat Diagn 2000;20:683-4.