Pregnancy detection: day 31

Pregnancy Detection

The following is a scan of a day 31 pregnancy. The embryo is in the middle of the vesicle with the regressing yolk sac located above and the developing allantois below. A diagram also appears at the bottom of the page. Look for the heartbeat in the center of the embryo mass. At this point you can clearly observe the embryo hanging down from the yolk sac. The point at which the embryo is attached to the yolk sac will become the umbilical chord (umbilicus).

Mare: Lady 4/1/06, c. checura - Day 31

Characteristics of the embryo:

Allantois easily seen and makes up majority of fluid surrounding the fetus.
Yolk sac is regressing but still visible.
Fetal heart beat is present in a viable pregnancy.
While limb buds are present they can not be seen on ultrasound images.
Brain is substantially developed.
Internal organs such as liver, and parts of intestine are present in the embryo.