Read Oxford Handbook of Midwifery Online
Authors: Janet Medforth,Sue Battersby,Maggie Evans,Beverley Marsh,Angela Walker
PRINCIPLES OF CARE IN THE SECOND STAGE OF LABOUR
275
Directed sustained versus spontaneous physiological pushing
Breath holding, closed glottis, and fixed diaphragm—commonly known as the Valsalva’s manoeuvre—is no longer recommended due to its negative effects (b see Breathing awareness, p. 246)
1,2
. At the peak of a contrac- tion the utero-placental blood flow ceases—a physiological factor that the fetus can cope with for short periods.
This technique is said to reduce the length of the second stage, however, a technique for pushing infers that something needs to be done in place of the body’s own efforts, which undermines the mother’s ability and instincts.
1,2,3
Spontaneous physiological pushing
This allows the woman’s body to tell her what to do. If she is left to push spontaneously, she will do so three to five times within a contraction, to coincide with extra surges. The length of pushing may be significantly reduced, but it is more intense and productive if the woman tunes into this natural pattern.
4
Disadvantages
Advantages
Midwives
8
(4), 168–9.
CHAPTER 14
Normal labour: second stage
276
Care of the perineum
Care of the perineum is an important part of the birthing process, both for the midwife and the mother. Perineal trauma can have far-reaching effects, influencing the woman’s physical, emotional, and sexual relation- ships for the rest of her life. Perineal trauma is associated with:
Much of the routine care of the perineum is based on custom and practice; however, recent studies have shown how changes in management can help to enhance perineal integrity and minimize trauma.
Management
There has been much debate about whether applying pressure on the fetal head to maintain flexion, and the Ritgen manoeuvre to assist extension, are of value. Review of the key physiological principles would suggest that intervention using these techniques interferes with normal birthing mechanisms, by increasing the diameter of the fetal skull, thus
inevitably leading to potential perineal trauma rather than preventing it.
This is best highlighted diagrammatically: see Fig. 14.2.
CARE OF THE PERINEUM
277
Flexion technique
Fig. 14.2a
The smallest diameter of the fetal head is maintained by an attitude of flexion. Further flexion applied by the birth attendant changes the position of the head to a larger diameter. This puts unnecessary pressure on the perineum, instead of its important role as a pivotal mechanism. Flexibility of the neck ensures the smallest diameter is maintained throughout the whole of the birth process.
Fig. 14.2b
The presenting part is halfway through the 90% curve of the birth canal. Partial extension occurs to maintain the smallest diameter (suboccipito-bregmatic). Extension of the head already occurs before it is visible therefore flexion at this point only maintains a larger diameter. As the birth canal is not straight there is no rationale for this technique.
CHAPTER 14
Normal labour: second stage
278
Ritgen manoeuvre
Fig. 14.2c
The Ritgen manoeuvre. As the fetal head emerges from the introitus, if over-extension is applied this results in the occipito-frontal diameter presenting – a considerably larger diameter. In an unassisted mechanism the head increasingly extends through the 90% angle so that it is able to utilize the resistance and pivotal force of the perineum and the pubic bone. This maintains the smallest diameter at the vaginal orifice.
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CHAPTER 14
Normal labour: second stage
280
Performing an episiotomy
In 1996 the World Health Organization (WHO) recommended an episi- otomy rate of less than 10% for normal deliveries. The only real indication for an episiotomy should be if the fetus is compromised in the second stage of labour and birth needs to be facilitated quickly. In rare cases a rigid perineum that is unquestionably obstructing the process of delivery may require episiotomy. Evidence suggests that:
1
Awareness of anatomical structures is important, especially the location of the external sphincter muscle, which extends 2.5cm around the anus (see Fig. 14.3). A medio-lateral incision is used, as opposed to the midline inci- sion, which is associated with increased incidence of third-degree tears.
Performing an episiotomy