[Measurement of topographic values during extraperitoneal cesarean section]

Topographic values were measured during extraperitoneal cesarean section in 23 cases. The results were as follows: (1) The average height from the upper edge of symphysis pubis to the bladder apex was 5.9 cm. The height of bladder apex increased with the prolongation of labor and dilation of the cervix. (2) Filling-up of the bladder was not necessary in primipara when the duration of the first stage of labor was longer than 4 hours and dilatation of cervix was more than 2 cm. (3) Before the onset of labor, the bladder should be filled up during operation, particularly in patients with floating fetal heads or abnormal presentations, e.g. breech or transverse. (4) The ratio of the distance between anterior peritoneal reflection and bladder apex to the distance between posterior peritoneal reflection and bladder apex was 1:3.