Briefly explain the main changes in the mother and fetus during each trimester of pregnancy.

First trimester-the mother experiences more frequent urination, may experience morning sickness, swollen breasts, and undue fatigue. The embryo develops various organ systems and at the end of the third month is called a fetus, indicating all systems are in place.

Second trimester-physical changes in the mother become more apparent and her breasts swell and waistline thickens. The placenta becomes well established.

Third trimester-it is the period of greatest fetal growth and weight gain. During the third trimester, the fetus must get large amounts of calcium, iron, and nitrogen from the foods the mother eats. During the eighth month, the respiratory and digestive organs develop.