Pregnancy and Birth

A full-term pregnancy lasts approximately forty weeks, or nine calendar months, and is divided into three phases, called trimesters, of three months each. During each trimester, the pregnant woman experiences various physical and psychological changes.

As the baby grows, the uterus enlarges, which produces an obvious change in the shape and appearance of the woman's body. Uterine enlargement is responsible for some of the physical and psychological changes that develop during the woman's pregnancy. High levels of two hormones that are present during pregnancy—estrogen and progesterone—trigger other physical and psychological changes.

During the first trimester, the woman may have morning sickness, which refers to persistent nausea or vomiting during the morning hours. Sometimes, though, the nausea can occur throughout the day or only in the evening. Other common changes during the first trimester are tender breasts and nipples, fatigue, and a desire for more sleep than usual, as well as frequent urination. Headaches and sensitivity to odors also may occur. In addition, the woman may notice that the skin surrounding her nipples has become darker and that a thin line of darker skin has appeared on her abdomen. During the second trimester, many of the physical changes disappear. Toward the end of the fifth month of pregnancy, the woman first feels the fetus move, an event that is called quickening. During the third trimester, the woman may have frequent backaches and may feel clumsy or awkward due to the change in her posture caused by the enlarging uterus. Other third-trimester physical changes include shortness of breath, heartburn or indigestion, more frequent urination, hemorrhoids, leg cramps, swollen ankles, and varicose veins. Shortness of breath is, however, frequently relieved about two to three weeks before birth, when lightening occurs, that is, when the uterus moves downward from the abdominal cavity into the pelvic cavity.

Psychological changes and associated behaviors are triggered not only by uterine enlargement and hormone levels, but also by the woman's culture. Studies of Western women indicate that during the first trimester, common feelings include excitement about the pregnancy or anger that an unplanned pregnancy has occurred. Feelings of ambivalence about a planned pregnancy are also common. On the one hand, the woman feels that she has achieved a much-desired goal, whereas on the other hand, she feels overwhelmed by the thought of caring for another human being. The woman also may feel worried or anxious about how she will cope with the birth and the care of a baby. The second trimester is frequently characterized as a time of psychological well-being. As the pregnancy progresses, the woman may have both positive and negative feelings about the changes in the size and shape of her body. The psychological changes of the third trimester may include a return of anxiety about the birth; concerns about changes in relationships with a partner, family, and friends; and financial worries. At the same time, the woman may feel excited about the forthcoming birth of her baby and the start of a new phase in her life.

Throughout pregnancy, dietary practices frequently are influenced by culture and folk beliefs. Foods and herbs may be used in rituals to ward off evil spirits. Pregnant women may be encouraged to eat certain foods, foods of a certain temperature, or foods of certain colors, and may be discouraged from eating other foods. Some foods are thought to be shocking to the woman's body or to cause a rash or other problem in the infant. Other foods are thought to influence the position in which the baby is born. In some cultures, the amount of food eaten is prescribed in the belief that less food will produce a smaller infant and, therefore, an easier birth. Food cravings may occur, especially during the second trimester, and then continue throughout the pregnancy.