Pseudo contractions are irregular, short in duration, with long intervals, sometimes strong and sometimes weak, without shortening of the cervical canal and dilatation of the uterine opening, and can usually be relieved after rest.
True contractions are regular and gradually increasing in intensity, lasting 30 seconds or more, with intervals of 5-6 minutes, accompanied by progressive loss of the cervical canal, dilatation of the uterine orifice and descent of the fetal previa (the part of the foetus that first enters the pelvic inlet), most of which cannot be relieved after rest.