-
Normal ranges of embryonic length, embryonic heart rate, gestational sac diameter and yolk sac diameter at 6-10 weeks.
Papaioannou GI, Syngelaki A, Poon LC, Ross JA, Nicolaides KH.
Fetal Diagn Ther 2010;28:207-19. -
Fetal head-to-trunk volume ratio in chromosomally abnormal fetuses at 11 + 0 to 13 + 6 weeks of gestation.
Falcon O, Cavoretto P, Peralta CF, Csapo B, Nicolaides KH.
Ultrasound Obstet Gynecol 2005;26:755-60. -
Gestational sac volume measured by three-dimensional ultrasound at 11 to 13 + 6 weeks of gestation: relation to chromosomal defects.
Falcon O, Wegrzyn P, Faro C, Peralta CF, Nicolaides KH.
Ultrasound Obstet Gynecol 2005;25:546-50.