Swollen calves in the second trimester. Because in the second trimester, the increasing uterus compresses the venous blood vessels, so that the venous blood returning to the heart, is obstructed to varying degrees, which leads to the symptoms of swollen legs. Therefore, pregnant women should pay attention to standing for a long time, to sit down properly to rest. After sitting for a long time, you should also change your posture and move your legs. Secondly, pay attention to the diet regulation. After pregnancy, the body’s ability to regulate salt and water decreases, so pregnant women should control the intake of salt in their daily lives. Generally, the daily intake of salt should not exceed 6 grams. For pickled foods with high salt content, mothers-to-be should eat as little or as little as possible. For most pregnant women, leg swelling is a common physiological phenomenon that has little impact on the growth and development of the fetus and the health of the mother. The obstruction of blood flow to the lower extremities and the compression of the inferior vena cava by the enlarged uterus in the second trimester cause an increase in venous pressure, resulting in swelling. It is important to note that pregnant women with lower limb edema need to monitor blood pressure closely in order to detect hypertensive disorders in pregnancy in a timely manner.