Pregnancy by the Trimester
Ben Gans and Antwine Johnson
Trimester 1
Starting after conception, you will begin to feel physical changes such as sore breasts, fatigue, frequent urination, split personality, and increased size around abdomen. It is best to begin taking prenatal vitamins and an exercise routine, as well as avoid alcohol.
Baby:
He or she will develop from a zygote to the size of a grapefruit-sized infant. His or her circulatory system will begin to form and beat with blood. His or her arms and legs will develop with bones articulating joints. Other organ systems forming are the nervous system (dual-hemisphere brain), digestive system, and skeletal muscles. Nails, peach fuzz and finger prints form late in this stage.
Trimester 2
At this point in your pregnancy, the nausea and mood swings will slow down, and your appetite will increase. Your abdomen will continue to grow, causing a shift in your center of balance and lower back pain. Cramps in muscles may also result from the baby's weight. You should also consider child birth classes and options for baby names by this point in time.
Baby:
As your baby continues to develop, the bones will begin to harden and facial features will move into the correct position. In this stage, he or she grows from 3 inches to 14 inches. Sensory systems also develop with the brain tissue, evident by the baby's response to noise stimulus. Superficially, hair and baby fat begins to develop also.
Trimester 3
At 28 weeks you will gain 11 pounds. Also, you will begin to visit your doctor every 2 weeks. At 31 weeks you will begin to leak colostrum or pre-milk, have a hard time sleeping at night, and contractions. At 41 weeks, if your baby isn't born, it will be induced by 42 weeks.
Baby:
By this point, the baby will finish growing to be around 6 pounds, and 19 inches. At 28 weeks the baby's eyesight is developing. At 31 weeks, he or she can turn his or her head and baby fat has accumulated for warmth. By the end of this trimester, the baby has prepared for birth by losing membranes and hair used for protection in the womb.