Abdominal Ultrasound on Embryo Development: Fifth, Sixth, Seventh and Eight Week

The gestational sac can be observed with the following characteristics :

• Oval or rounded shape with limpid bound arise
• Homogenous , trophoblastic rim greater than 5 mm
• No internal contour irregualates
• Progressive growth (1 mm per day)

The abdominal 3D gestational sac vision at this age is not easy to see, and there is no improvement when compared only twith 2D. At the present the transvaginal route is useful.

The sacs shape is round between the fifth and sixth week and becomes oval later on. Irregular forms such as enlarged. Comma-like shape, should not be considered abnormal unless accompanied by other anomalies , such as :

• -Irregular growth: no growth,too slow , too rapid
• -Decidual refringency changes
• -Contour irregular
• -Embryo not visible (vanishing).etc

Abnormal sac forms in normal evaluation pregnancies are common in cases myomas, ovarian cyst and distended baldder of sigmoid etc

The gestational sac wall thickness decrease as gestation progress, due to the progressive atrophy of the deciduas capsularis and parietalis e.tc

The measument to visualization embryo, the crown-up length should be measurement. This should be made from the chepalic pole to the rump, taking care to measure embryonic curvature. The crown-up length should ne measured across the dorsall curvature.

On Sixth week pregnancy, the most important finding is embryonic visualization, It appear as an acho-refrigent, round structure located in the inferior pole because of its specific gravity being greater that that the amniotic fluid. Its length is approximately mm.

The gestational sac grow approximately 1,15 mm per day, so that at the end of the sixth week it measures 20 mm, up from 10 mm at the beginning of that week. The embryonic growth is 1 mm per day, reaching 17-17mm at the end of the sixth week.

Seventh Week pregnancy along with increasing size f the embryo and sac, the most important feature is the visualization of cardiac activity. The embryo remains round

Eight week , the limb buds appear in an embryo that is still rounded in shape. So called jerky embryonic movement are detectable. Because the embryo in fact moves up and down repeatedly within sac. The yolk sac can be observed in allocation near gestational sac.