Pregnancy vomiting can occur at any time of the day or night, but it is usually more pronounced in the morning when you wake up. The timing of pregnancy vomiting varies according to the pregnant woman’s physical condition, mood and hormone secretion in her body. If pregnant women often have pregnancy vomiting at night, there are many possible reasons, mainly considering the following points: 1. endocrine factors: the vagus nerve is excited at night, and the vomiting center does not adapt to the increased neurohormones, resulting in pregnancy vomiting at night; 2. dietary factors: pregnant women eat too much greasy and indigestible food at dinner, and if they eat too much at dinner and go to sleep before digesting the food, it may increase the burden on the gastrointestinal tract, resulting in pregnancy vomiting. 3, mental factors: pregnant women’s nervousness, mental anxiety, poor sleep quality or irregular diet, fasting at night and other factors can also lead to pregnancy vomiting at night; 4, other factors: the pregnant woman’s personal physique, weather, environmental changes and other factors can also cause pregnancy vomiting at night to a certain extent. In short, long-term severe vomiting may lead to loss of appetite, malnutrition and other chain reactions, as well as adverse effects on the development of the fetus, which should be taken seriously and treated with rehydration if necessary.