2008 Volume 22 Issue 1 Pages 49-64
The objective of this study was to measure the pressure on the fingers and palms of persons who assisted normal supine labor by protection of the perineum from expulsion of the fetal head to trunk, aiming at development of a midwifery technique that minimizes stress on the perineum. Experienced and novice midwives were compared, and skilled protection of the perineum was explained from the viewpoint of the pressure applied.
Subjects and Methods
Subjects who met the study conditions were primiparae and multiparae with an expected date of delivery between November 2005 and late October 2006. Seventeen primiparae, 17 multiparae, 4 skilled and 11 novice midwives gave consent to and participated in the study. For measurements, a compact pressure transducer (PSM-1KAB, Kyowa Electric Instruments) and sensor interface board (PCD-300A, Kyowa Electric Instruments) were used. The midwives assisted the labor with their hands attached to ultra compact pressure transducers at 4 and 6 sites on their right and left hands, respectively, as identified in a preliminary study. Data were collected from the appearance of the fetus to expulsion of the fetal trunk. Basic parameters of the pressure load on each palmar site measured on each palm were calculated and compared statistically.
The experienced and novice midwives used the following regions differently: The right index finger pad (2), middle of the right index finger (3), medial side of the middle finger between the left first and second joints (6), and tip of the left little finger (9). [From 30 seconds before expulsion of the fetal head to its expulsion] The novice midwives loaded pressure on the right index finger pad (2) when protecting the perineum, and the maximum value (33 kPa) was twice that of the experienced midwives. The experienced midwives loaded pressure on the middle of the right index finger (3) to protect the perineum, and the maximum value (29 kPa) was 4 times higher than that of the novice midwives. The experienced midwives also loaded pressure on the left index finger (6), and the maximum value (18.8 kPa) was 3 times higher than that of the novice midwives. [From crowning to expulsion of the fetal head] The experienced midwives constantly loaded about 5 kPa on the tip of the little finger (9) to protect the perineum, but the novice midwives did not load any pressure on this site.
Pressure applied for protection of the perineum by midwives cannot be expressed and explained by words, but it could be measured mechanically for a further explanation. It was demonstrated that techniques of the experienced midwives could be presented as values by comparison with novice midwives.