Re: A question of angle of view

Abstract

The 120° cut-off in our study was never meant to be an all or none threshold, but one cannot ignore the fact that 90% of Kalache's patients and all of ours had vaginal deliveries once this threshold was exceeded. Our technique involves applying the transducer to the perineum below the symphysis in a direction that enables the operator to obtain an angled view that includes both the entire cartilaginous length of the median pubic raphae and the fetal head. After reading the letter from Palteiri and Nizard, we tried elevating the probe to 6 cm above the plane of the bed and found little difference in the TPU angle in the same patient. However, over the years we have noted that at low stations there can be up to a 30° difference in the TPU angle of progression as the head advances and regresses during and after a contraction. Paltieri and Nizard obtained their TPU angles 64 s apart, which could explain their finding. We are curious as to whether they found this to be a consistent finding. Finally, as Duckelmann et al. point out in their response to Paltieri and Nizard's letter in the September issue of the Journal5, the digital assessment of fetal station has been demonstrated to be flawed, and we feel we have shown in one of our papers2 that the TPU estimation of station is far more precise than is the notoriously subjective and inaccurate digital exam. As all authors, including ourselves, agree, the TPU angle of progression has great potential in the laboring patient. However, further prospective investigation is needed for this potential to be fulfilled. A. F. Barbera*, J. C. Hobbins , * Department of Obstetrics and Gynecology, Denver Health Medical Center, Mail Code 0660, 777 Bannock, Denver, CO 80204, USA, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, USA