Table 1.
Number of embryos for each measurements.
Table 2.
Morphometric evaluation.
Figure 1.
Ultrasound images of fetal development from embryonic day 5.5 to 9.5.
Representative images of the implantation site at E5.5 showing the apposition of the blastocyst trophectoderm with the uterus (a). At E6.5, a small echolucent cavity containing the embryo is visualized inside the decidua (b). At E7.5, the amniotic and exocoelomic cavities and the ectoplacental cone region are discernable (c). At embryonic day 8.5, the heart, head and whole embryo are visualized (d). At E9.5, the amniotic membrane, yolk sac and cerebral ventricles are visible, while a Doppler spectral trace of ventricular inflow and outflow can be observed in the “U shaped” heart tube (e–h).
Figure 2.
Ultrasound images of fetal development from embryonic day 10.5 to 14.5.
At E10.5, it is possible to identify the umbilical cord, placenta and eyes (a, b); a sagittal view of a dead embryo is shown in (c). At embryonic day 13.5, crown-rump length (d), placental length and placental thickness (e) can be measured; the distinction between the fetal thorax and abdomen is defined (f); eyes with lens (g) and vertebral column (h) are visible. At E14.5, the occipital-snout length measurement can be reported (i).
Figure 3.
Ultrasound images of fetal development from embryonic day 14.5 to 16.5.
At E14.5, progressive ossification is observed in the skull (a) and ribs (c), and the interventricular septum is completed (b). At 15.5, the development of the vertebral elements and humerus is complete (d, e). At E16.5, the curl is clearly visible (f). Dorsal aorta and corresponding Doppler spectral trace at E16.5, which exhibits a rapid upstroke and return to zero velocity during diastole (g, h).
Table 3.
Spearman’s correlation coefficient and significance of each embryonic parameter.
Table 4.
Best-fit regression coefficients and standard error for the three groups of variables.