Whether blood in the sputum of pregnant women will affect the fetus needs to be analyzed in relation to the specific etiology. However, regardless of the cause, it is recommended to seek medical treatment in a timely manner to avoid delaying the condition and causing adverse effects on the fetus. 1. chronic pharyngitis/upper respiratory tract infection: symptoms such as dry throat, itchy throat and cough will generally appear, and when the cough is intense, it may lead to local capillary rupture, resulting in blood in the sputum, which generally does not affect the fetus. If the infection is further aggravated and systemic symptoms such as high fever appear, it may affect the fetus, such as causing miscarriage; 2. Bronchiectasis: some pregnant women have a history of bronchiectasis, and the typical symptoms of bronchiectasis are repeated coughing, coughing up sputum and coughing up blood, which can easily be combined with infection. If the amount of coughing blood is relatively large, it may cause serious anemia in pregnant women. Anemia in pregnant women can cause a decrease in the oxygen-carrying capacity of blood, resulting in fetal hypoxia in the uterus; 3. Tuberculosis: tuberculosis itself is an infectious disease, and Mycobacterium tuberculosis can spread through the blood and enter the fetus through the placenta, causing congenital tuberculosis. In addition, the use of anti-tuberculosis drugs during pregnancy can have adverse effects on the fetus, such as the commonly used anti-tuberculosis drug isoniazid, which may pass through the placenta and lead to fetal malformation or cause fetal brain nerve damage, deafness, etc.; 4, lung tumors: If a pregnant woman has a malignant lung tumor, which is itself a consumptive disease, it will lead to a decline in the function of the pregnant woman’s body, and the pregnant woman herself may suffer from malnutrition and oxygen deficiency, which directly affects the supply to the fetus. It directly affects the supply to the fetus, leading to intrauterine growth retardation and intrauterine hypoxia of the fetus, etc.