Pregnancy is a physiological condition and a major event in the life of every woman and her family. It is formed by implanting a fertilized egg in the endometrial uterus. A normal pregnancy lasts ten lunar months or nine calendar months, or 40 weeks or 280 days. During pregnancy, a pregnant woman goes through a series of physiological, anatomical, organic and psychological changes that ensure the body's adaptation to the "other state", ie pregnancy, fetal growth and development, preparation for childbirth, the birth itself and breastfeeding. Pregnancy and exercise require numerous changes and adjustments to the body functions of the pregnant woman discount breathing, heart rate, circulation and energy use. Skeletal muscles adapt to endurance exercises primarily through a minimal increase in the transverse average of slowly contracting fibers due to the fact that low to moderate intensity of aerobic activity of the primary affects these muscle fibers. Skeletal muscles consequently develop more strength due to load-bearing exercises due to muscle hypertrophy and activation of increased number of muscle fibers. When exercising at low intensity (30 - 50% of maximum aerobic capacity) the response of the respiratory system increases overall ventilation to meet metabolic needs or oxygen supply to the muscles. At moderate to high intensity exercise, the ventilation volume continues to increase in part to meet the muscle's need for oxygen. While designing an exercising program for pregnant women, the physiotherapist should keep in mind the impact of changes in physical activity on the fetus and fetal responses to exercise during pregnancy (changes in heart rate, variability of acceleration and deceleration, changes in fetal activities and movements, changes in oxygen concentration and carbon and carbon status. dioxide, thermoregulation and changes in uteroplacental flow).