It is undoubtedly very important for every pregnant woman to have a safe and smooth perinatal period. However, what many people do not know is that almost all pregnant women are at risk of heart failure, even those who do not have any heart disease on their pre-pregnancy physical exam. Why is this? In fact, the risk of heart failure is determined by the unique physiological characteristics of maternity. This is because the blood volume of a pregnant woman begins to increase gradually from 6-8 weeks of gestation, reaching a peak at 32-34 weeks of gestation and remaining at this level until after delivery. The increase in blood volume during pregnancy can reach 40-45% of the pre-pregnancy blood volume. The continuous contractions during labor cause a large amount of fluid in the uterus to be squeezed into the circulation, which further leads to an increase in systemic blood volume. With the delivery of the fetus, the intra-abdominal pressure drops sharply, and a large amount of blood is pumped from the body circulation to the internal organs, resulting in a dramatic change in the hemodynamics of the mother’s body. In the early puerperium, contractions remain, aiming to return the still enlarged uterus to its pre-pregnancy level after delivery, while the side effects of contractions continue to bring blood from the uterus into the body circulation, and in addition the fluid retained between the tissues of the maternal body during pregnancy begins to gradually return to the body circulation. All of these maternal physiological characteristics lead to a large increase in blood volume, causing an increase in cardiac output and a faster heart rate, resulting in an increased cardiac workload. Therefore, maternal heart failure is most likely to occur at 32-34 weeks of gestation, during labor and delivery, and in the early puerperium. Maternal heart failure is very dangerous and can lead to increased maternal and fetal mortality. So, how do you recognize early heart failure? The occurrence of the following 3 conditions can indicate early heart failure: 1 chest tightness, palpitations and shortness of breath after light activity; 2 heart rate exceeding 110 beats per minute at rest and breathing exceeding 20 breaths per minute; 3 sitting up to breathe at night due to chest tightness or going to the window for fresh air. The above 3 conditions can indicate early maternal heart failure. If these conditions occur, we hope that the mother will consult a specialist at the hospital as soon as possible so that she can receive timely treatment.