You are reading this because you are 6 weeks pregnant now. In those cases where earlier confirmation of pregnancy is required, using ultrasound scan can be recommended but still detection of embryo in less than 8 weeks time is quite difficult. Therefore trans-vaginal ultrasound scan is offered. This is done by placing a probe into the vagina. This will only indicate the faint heart beat— detectable at six weeks of pregnancy— of the developing embryo.
At later stages baby’s size is the criteria of measurement. Size of the baby, from top to bottom, will determine the stage of pregnancy, which then can be used to safely predict the Estimated Date of Delivery (EDD). As fetus size varies at faster rate after 10 weeks of pregnancy, predictions based on such scans are more accurate if they are done at that time.
Development in 6th Week Pregnancy
Two-chambered heart (yet not complete but developing) will beat. But the most developed system at this stage is nervous system. Liver, out-pacing the development of rest of the digestive system, starts developing.
The baby, now floating in the bubble of fluid will acquire a distinct shape resembling a tiny seahorse. This is so because of the asymmetric development of the tissues. Tail grows faster than the front end. The bubble of fluid finally turns into the amniotic sac known as yolk sac. After this stage, until the formation of placenta, oxygen and nutrients are provided by this yolk sac.
Because, at initial stage of development brain and head develops more rapidly, head seems out of proportion to the rest of the body. Afterwards limb buds would appear and other facial features such eyes and ears would start developing.