Myometrial thickness has undergone sonographic evaluation during normal pregnancy, labor and postpartum and in certain situations such as twin pregnancy, polyhydramnios and preterm premature rupture of membranes.Some studies showed decrease in the myometrial thickness in the 2nd and 3rd trimesters compared with the 1st trimester and also in specific pregnancies which are associated with preterm labor such as twin pregnancy and polyhydramnios. Lower uterine wall lies close to the cervix and it is hypothesized that the changes that occurred in the cervix could possibly involve the adjacent lower uterine wall as well. The lower uterine wall can be measured precisely using transabdominal ultrasound which is readily available in almost all clinical settings. The normal value of lower uterine wall thickness and the correlation between the lower uterine wall thickness and cervical length is of great importance to find a surrogate marker of a short CL in order to overcome the obstacle mentioned above.