At week 16, the fetus's nervous systems and skeletal systems begin to coordinate movement, according to Similac. At this stage in the pregnancy, the fetus is about 4-5 inches long and has developed facial muscles and eyelashes. With the help of a steady supply of calcium, the baby can build and strengthen his bones. The fetus's head is also now more erect than ever, and his scalp pattern is beginning to develop.
At week 16, the fetus's eyes can now move side to side and also perceive light. According to BabyCentre, the fetus's head is now visible, and her circulatory system and urinary tract are fully working. The fetus is unable to inhale and exhale amniotic fluids through his lungs. At week 16, the fetus's circulatory system are now fully working, and the fetus can pump about 25 quarts of blood daily, according to Babycenter.com.
According to Baby2see.com, the fetus is now also able to hear voices and sleep and dream. The baby weighs significantly more and can now grasp with his hands and kick. At week 16, the women's pregnancy is now more conspicuous than in the previous weeks. In addition, the woman starts to feel slight pain as she moves.