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Maternal serum placental growth hormone at 11-13 weeks' gestation in pregnancies delivering small for gestational age neonates.
Sifakis S, Akolekar R, Kappou D, Mantas N, Nicolaides KH.
J Matern Fetal Neonatal Med 2012;25:1796-9. -
First-trimester maternal serum activin A in pre-eclampsia and fetal growth restriction.
Ong CY, Liao AW, Munim S, Spencer K, Nicolaides KH.
J Matern Fetal Neonatal Med 2004;15:176-80.