Clinical application of the perineal scan: prepartum screening for cord presentation

Real-time linear-array ultrasonographic scanning was performed from the perineum on 12 primiparous term women with the fetus in breech or foot presentation. Scanning was done with the patient initially in lithotomy position and then in semi-Trendelenburg position if a better view was required. The technique appears to be excellent for visualization of the forelaying umbilical cord even when the cervix is closed and is not affected by the acoustic shadow of the public arch. The information obtained by the scanning may be of value in avoiding or improving perinatal mobility of breech/footling fetuses and in providing better perinatal management.