According to WebMD's pregnancy guide, expectant mothers gain weight around week 12 and, depending on skin elasticity, develop stretch marks around the breasts, abdomen, hips or buttocks. By week 16, women should be visibly pregnant with leg veins becoming more apparent. Some acne is to be expected.
Once a pregnancy enters its 12th week, the chances of miscarriage drop significantly. WebMD states. The end of the first trimester marks the full development of the baby's limbs and extremities, with fingernails, teeth and toes just starting to form. Although the baby's reproductive organs are developing, at this stage the sex is difficult to determine.
Though not immediately necessary, the mother should acquire maternity bras and clothing, and she may find it more comfortable to wear looser clothing. By week 16, the baby's arms and legs are moving and the nervous system is functioning while the mother's uterus begins to grow upward in the abdomen. The mother can begin considering what kind of prenatal tests she wants performed. Because pregnancy relaxes the bowels, she may experience constipation that can be alleviated through diet and moderate exercise. WebMD advises sleeping on the left side in order to help improve circulation and investing in a pregnancy pillow for increased full-body support.