If you can't lose weight after three months of pregnancy, then in the first three months of pregnancy, because the embryo is in the development stage, especially the connection between the placenta and the maternal uterine wall is not tight, it is likely that the uterus will be shaken due to improper movements, so that the placenta will fall off and cause abortion. Expectant mothers should try to choose slower movements, such as jumping, twisting or fast spinning.