Sleeping position in late pregnancy advocates the left side lying position, but not necessarily, do not lie flat can. The main reason for advocating the left lateral position is that most of the uterus is in right rotation. The uterus rotates to the right, if you take the left side lying position, you can restore the normal anatomical position of the uterus to a certain extent, improve the blood flow of the uterus and placenta, increase the blood flow of the fetus and the placenta, which is beneficial to the fetus to a certain extent. But it is not necessarily only the left lateral position, some pregnant women left lateral position for a long time, there may be a variety of discomforts, if these symptoms appear, you can change the position into the right lateral position, but it is best not to lie down, will cause postural hypotension. The above health knowledge is for reference only, the specific circumstances need to be examined in a regular hospital, by a professional physician to make judgments.