Women who are 38 weeks pregnant are considered to be 9 months pregnant. During this point in a pregnancy, the baby is around 20 inches in length and weighs around 7.5 pounds. From 38 weeks until the time the baby is born, the baby continues to gain weight.
At 38 weeks pregnant, the baby's development is completed. The main job of the baby and mother at this point in the pregnancy is for the baby to gain weight. The more weight the baby gains, the better the baby is likely be at regulating her own body temperature after she is born.