Trainees and students in midwifery and obstetrics can practice correctly assessing the progress of the birth by palpating, using the 3B Scientific Birth stages trainer. By practicing on the birth stages trainer, the standard of clinical practice in midwifery and obstetrics can be considerably improved. The trainer consists of a set of 6 inserts that show the level of cervical dilation and effacing. The inserts can be used both as stand-alone trainers and as an extension module for birth simulator P90. The inserts look the same from the outside, but indicate, using a number code on the back, the condition of the cervix on the inside.