Advertisement

Reply

Published:September 15, 2017DOI:https://doi.org/10.1016/j.ajog.2017.09.007
      We thank Dr Suzuki for the comment about our article that showed that transperineal ultrasound measurement of the distance between the leading part of the fetal skull and the perineum was a useful supplementary tool to predict difficult operative vaginal delivery.
      • Kasbaoui S.
      • Severac F.
      • Aissi G.
      • et al.
      Predicting the difficulty of operative vaginal delivery by ultrasound measurement of fetal head station.
      We agree that it might be even more interesting to assess the station of the largest circumference of the fetal head, rather than the station of the leading part of the fetal skull, but do we actually have such a tool? To our knowledge, there is no study that has evaluated this kind of assessment thanks to a transabdominal ultrasound scan, and we believe it might be a pretty challenging measurement. For a technique to be useful and usable, it must be simple and reproducible, which is the case with the perineum-to-skull ultrasound distance (PSUD).
      The reliability of transvaginal assessment of fetal head station as defined by the American College of Obstetricians and Gynecologists classification is poor.
      • Dupuis O.
      • Gaucherand P.
      • Cucherat M.
      • et al.
      Birth simulator: reliability of transvaginal assessment of fetal head station as defined by the American College of Obstetricians and Gynecologists classification.
      We believe that PSUD measurement offers a more objective and reliable assessment of fetal head station, even though it does not replace digital examination. We agree that the molding of the fetal head may lead to an incorrect assessment of fetal head station using our ultrasound technique, but the issue may be the same with the digital examination. However, the issue related to the clinical assessment in the case of caput succedaneum is overcome by ultrasound technique, since we measure the distance from the perineum to the fetal skull, not the fetal skin.
      Finally, even though transperineal ultrasound scanning is not a perfect tool (but are there any?), PSUD measurement is simple and reliable, and we believe it is a useful supplementary tool to the usual clinical findings.

      References

        • Kasbaoui S.
        • Severac F.
        • Aissi G.
        • et al.
        Predicting the difficulty of operative vaginal delivery by ultrasound measurement of fetal head station.
        Am J Obstet Gynecol. 2017; 216: 507.e1-507.e9
        • Dupuis O.
        • Gaucherand P.
        • Cucherat M.
        • et al.
        Birth simulator: reliability of transvaginal assessment of fetal head station as defined by the American College of Obstetricians and Gynecologists classification.
        Am J Obstet Gynecol. 2005; 192: 868-874

      Linked Article

      • Comment on: Predicting the difficulty of operative vaginal delivery by ultrasound measurements of the fetal head station
        American Journal of Obstetrics & GynecologyVol. 218Issue 1
        • Preview
          I read with interest the study by Kasbaoui et al,1 who investigated the clinical usefulness of measuring the perineum-to-skull ultrasound distance to predict the difficulty of operative vaginal delivery. However, I cannot agree with the conclusion reached. To perform operative vaginal delivery, I believe that the position of the largest circumference of the fetal head is more important than that of the lowest part of the fetal head. We sometimes have encountered cases in which the position of the largest circumference was higher than the pelvic inlet, whereas the lowest part was descending because of molding of the fetal head, particularly in cases of occiput-posterior presentation.
        • Full-Text
        • PDF