This groove will eventually close up forming a tube in which the spinal cord and brain will develop. There is already a bulge in the center of the embryo where the heart will be formed and the beginnings of a rudimentary vascular system in place. During the sixth week, symptoms may hit in full force. Morning sickness may occur on a regular basis every morning or even stick around the entire day. In severe cases, vomiting may become a problem the doctor may want to address if it interferes with a woman s ability to keep any food down or she is losing a substantial amount of weight.
Fatigue sets in and stays while hormonal levels often cause moodiness and irritability.
It is important at this stage for the woman to listen to her body and rest as much as possible. The embryo at this time has developed the spinal tube and her brain is growing to fill the head. Dark areas can be seen on either side of the head. These are optic vesicles and will eventually give the baby its sight. The heart may start to beat this week and tiny limb buds emerge.