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6.1 Experimental evaluation of a new device and estimation of forces applied to the impacted head at CS
  1. GSJ Tydeman1,
  2. A Briley2,
  3. A Sheenan2,
  4. P Seed3
  1. 1NHS Fife, Kirkcaldy, UK
  2. 2GSST, London, UK
  3. 3KCL, London, UK


When the fetal head becomes impacted at caesarean section, delivery may be aided by elevation of the head with an assistant’s fingers transvaginally. Serious fetal complications have been described. We developed a novel device (Tydeman Tube: TT) to elevate the fetal head and tested it on a simulator (Desperate Debra: DD).

Using identical positions of the fetal head over 4 different difficulty settings, 5 attempts at elevation were made digitally and by TT. A measured force was then applied to the simulator to achieve the same elevation. The area applied to the fetal head was calculated for the TT. To determine the area applied digitally, the fetal head within DD was covered in paper and the operators fingers covered in ink.

Greater elevation was achieved using the TT than digitally with a mean of +9.1mm (range 26–48 mm p < 0.001). Greater force (0.42 Kgf p < 0.001) was applied to the head using the TT to achieve this greater elevation, on the most difficult setting the mean forces applied to the head were 8.25 Kgf, however, as the force was spread over a total area of 6.97 cm2 in comparison of 2.0 cm2 digitally, the mean pressure was lower with the TT by 2.3 Kg.cm2 (p < 0.001).

The force and pressure applied to a fetal head during disimpaction are estimated we believe for the first time. The use of the TT was associated with lower pressure and greater elevation and may be associated with greater success and fewer complications. We will now proceed to clinical trials.

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