Fetal Changes during 3rd, 4th, 5th 6th Week
The fetus consists of cells (blastocyst) that is the size of a pin and ranges from 0.078 inches to 3/4th inch long.
Part of the blastocyst forms the placenta and releases the human chorionic gonadotropin (hCG).
The heart, spinal cord, brain, skin, circulatory system, gastrointestinal tract, lungs, thyroid, pancreas, eyes, ears, skeleton, and the gastrointestinal tract begin to develop at this stage.
Heart beats steadily
Development of brain
Webbed hands and legs
Lungs, nose, jaw bones form