Pregnancy

Pregnancy is the period of gestation before birth occurs. In human women, that period normally lasts for approximately 40 weeks (280 days). Women of childbearing age are encouraged to have pap smears, vaccinations, basic lab work, and pelvic examinations before becoming pregnant to identify potential problems or preexisting conditions. It is recommended that women who are trying to get pregnant begin taking vitamins containing folic acid to reduce risks of birth defects.

As a woman's body prepares for pregnancy, multiple changes occur and hormone levels fluctuate wildly.

The first sign of pregnancy is usually a missed menstrual period, and at-home pregnancy testing kits are now available that can detect pregnancies even earlier. Early prenatal care is essential. Toward the end of the pregnancy, examinations may be weekly, or even more frequently in the case of at-risk pregnancies.

During the 1920s following the food shortages of World War I, dieting became a common practice in industrialized countries. From then until the 1970s, most physicians limited weight gain during pregnancy [Page 1412]to 15 to 20 pounds. Smoking was touted as a way of gaining weight, and manuals for mothers-to-be insisted that smoking no more than a pack a day of cigarettes was perfectly safe. In 1971, the chairman of the board of Phillip Morris appeared on national television to advise women that smoking would result in smaller babies and make birthing easier.

By the 1980s, weight restrictions were relaxed for women who were not overweight at the onset of pregnancy. Normal pregnancy-related weight gains now vary from 25 to 35 pounds. Pregnant women are instructed to eat balanced diets, take vitamins, folic acid, and avoid tobacco and caffeine. Drinking alcohol or taking drugs or herbs not approved by medical providers may result in damage to the fetus.