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Prediction of spontaneous preterm delivery from maternal factors, obstetric history and placental perfusion and function at 11-13 weeks.
Beta J, Akolekar R, Ventura W, Syngelaki A, Nicolaides KH.
Prenat Diagn 2011;31:75-83. -
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.