The fetus spends more than half of its time in sleep, with no less than 12 hours of sleep per day. However, the fetus sleeps for a relatively short period of time, mostly within half an hour, but it wakes up more frequently, and every time the fetus wakes up, it plays in the uterine cavity for a while and then goes back to sleep, repeating this state every day, without distinguishing between day and night. If the fetus does not move, it will continue to do so for 20 minutes, mainly to consider whether the fetus is sleeping or not. If the fetus has little fetal movement and little stimulation, you can gently push the abdomen to give him some sound stimulation and then do the relevant examination on it. The fetus will absorb nutrients more effectively during sleep, develop as soon as possible, and gain weight by accumulating fat under the skin in the second trimester.