31. Principles of intrapartum skills
Pushing: directed or spontaneous214
Management of the perineum216
The umbilical cord216
Role and responsibilities of the midwife219
Having read this chapter the reader should be able to:
• discuss the evidence and opinions relating to recognition, duration, pushing, positions, nuchal cord and perineal management during the second stage of labour
• discuss the preparation for and conduct of a normal delivery
• describe how to infiltrate the perineum and incise an episiotomy
• discuss the role and responsibilities of the midwife throughout.
The second stage of labour lasts from the time the cervix is fully dilated until the birth of the baby, during which time the baby descends and rotates through the pelvis, the contractions change to become expulsive and the perineum stretches and thins out. This chapter will review the current evidence and clinical skills utilised during care in the second stage of labour and will encompass a discussion on the definition and duration of the second stage, the effects of directed and spontaneous pushing, different maternal positions and the management of a nuchal cord. The chapter concludes with a discussion on when and how to undertake an episiotomy.
The second stage of labour has traditionally been defined by a very clinical description: from full dilatation of the os uteri to the complete birth of the baby. It is now recognised that this stage of labour has both a passive and an active phase [National Institute for Health and Clinical Excellence (NICE) 2007].
The passive phase is the time from when the cervix is fully dilated but there is no urge to push. This has also been referred to as the ‘rest and descent’, ‘rest and be thankful’ or the ‘pause for rotation’ stage when the fetus descends passively (Brancato et al., 2008, Long, 2006 and Williams, 2007). Long (2006) suggests that this follows the transition phase, which occurs at the end of the first stage, and that it is a time when the woman may feel drowsy and relaxed; the presenting part may still be high. Yildirim & Beji (2008) argue that women cannot push effectively if the urge to push is absent and that pushing during the passive phase should be discouraged as this can lead to maternal exhaustion.
The active phase is recognised when the woman experiences expulsive contractions and has a strong urge to push, the cervix is fully dilated and the baby is visible (NICE 2007). The active phase will also commence when the woman begins to push once the cervix is fully dilated even in the absence of expulsive contractions, for example, with epidural anaesthesia (NICE 2007). The urge to push begins with the stimulation of the Ferguson’s reflex as the fetus descends onto the pelvic floor.
Delaying pushing until the woman is in the active phase of the second stage has many advantages for both the woman and the baby. These include: less maternal exhaustion, increased confidence in her own ability, less perineal trauma, reduced incidence of bladder and pelvic injury, reduced risk of instrumental delivery, reduced incidence of fetal heart abnormalities, higher Apgar scores at 1 and 5 minutes and higher umbilical cord arterial pH (Allbers and Borders, 2007, Brancato et al., 2008, Nicholl and Cattell, 2006, Roberts and Hanson, 2007, Roberts et al., 2004, Schaffer et al., 2005, Simpson and James, 2005 and Yildirim and Beji, 2008).
Recognition of the second stage has been classified by signs such as a change in contraction frequency and nature (expulsive), a heavy blood-stained show (as the operculum descends), pouting of the vulva and anus (as the fetal head descends onto the soft tissues), visible fetus at the introitus (always ensure this is not caput succedaneum) or use of vaginal examination which reveals the absence of a locatable cervix. However, skilled, intuitive, observant midwives will be very familiar with situations in which the urge to push is gradual or arises before full dilatation. Equally, the woman may become particularly vocal or particularly quiet and withdrawn, have a purple line that extends up the anal cleft (Hobbs 1998), display changes in abdominal shape (Burvill 2002) or sacral curve (rhombus of Michaelis; Sutton 2003) or feel that she can’t go on, is tired or – in contrast – is renewed with energy. Our researched understanding of these issues remains limited; nevertheless a truly ‘tuned in’ midwife will support the woman in her intuitive actions and sounds while maintaining good clinical observation and skill.
NICE (2007) suggests that the baby should be born within 3 hours (nulliparous women) or 2 hours (multiparous women) from the beginning of the active phase for most women although they suggest referral may be required an hour before the end of these time limits. Cheng et al (2007) found that a second stage lasting longer than 3 hours for multiparous women was associated with increased risk of operative delivery, increased maternal morbidity and lower Apgar scores. The length of the second stage will be affected by factors such as maternal position and epidural anaesthesia and the midwife should continue to observe for signs of normality and progress whilst recognising and managing any deviations from the norm.
Pushing: directed or spontaneous
Spontaneous pushing is likely to occur when the woman reaches the active phase of the second stage of labour due to the strong urge to push that accompanies this stage. Women may not begin to push until the contraction has built up and will often use short pushes lasting 5–7 seconds 3–5 times during a contraction (Di Franco et al., 2007 and Perez-Botella and Downe, 2006). The duration of the second stage is not significantly increased with the use of spontaneous pushing (Sampselle et al 2005), with some studies suggesting the time is reduced (Yildirim & Beji 2008).
Directed pushing occurs when the woman is told how to push – usually this involves breath holding, taking breaths quickly between pushes and 3–4 sustained pushes from when the contraction begins to when it ends. Breath holding increases intrathoracic pressure which can decrease the venous return to the heart, thereby reducing cardiac output and blood pressure. This in turn can reduce uterine blood flow and placental perfusion, and the amount of oxygen available to the fetus, increasing the likelihood of fetal heart rate abnormalities occurring (Perez-Botella & Downes 2006, Roberts & Hanson 2007). Hanson (2009) advises that women should be encouraged to push spontaneously or breathe through a contraction where fetal heart rate abnormalities occur until the fetus recovers. Additionally there is more strain placed on the urinary, pelvic and perineal structures increasing their risk of damage (Roberts and Hanson, 2007 and Schaffer et al., 2005). Breath holding can make women feel dizzy, causing them to gasp; a sudden surge of blood back to the heart may occur, resulting in rebound hypertension (Perez-Botella & Downes 2006).
Women should be encouraged to follow what their bodies are telling them to do and push when they have the urge (NICE 2007). In some situations the woman may not experience the urge to push (e.g. epidural anaesthesia). In this situation women may need some instruction on when and how to push (Young 2005); the principles of spontaneous pushing should be followed, for example, no breath holding, short bursts allowing the contraction to build up first.
De Jonge et al (2007a) propose that the routine use of the supine position should be considered an intervention in normal labour as when given the choice women opt to use a variety of positions during the second stage of labour. They highlight the importance of midwives facilitating choice for women rather than encouraging a semi-recumbent position which is more comfortable for the midwife. Lewis et al (2002) agree suggesting that women who are able to move around have an increased sense of control and require less analgesia. NICE (2007) also recommend women should be encouraged to adopt the position of their choice whilst being discouraged from lying supine or semi-supine.
Gupta et al (2004) found the use of an upright position (standing, squatting, kneeling, all fours, birthing chair or stool, sitting upright) reduced the length of the second stage, the incidence of assisted deliveries, the incidence of abnormal fetal heart rates and reporting of less severe pain. There was also an increased risk of second-degree tears and blood loss greater than 500 mL. However, Allbers & Borders (2007) found that fewer perineal tears and less pain were associated with upright and lateral delivery positions. De Jonge et al (2007b) found the increased blood loss associated with upright positions originated from perineal damage, those women with an intact perineum did not have an increased blood loss when semi-sitting or sitting. Di Franco et al (2007) consider upright positions make use of gravity and allow the pelvic diameters to increase although they acknowledge they are more tiring than semi-recumbent positions. To combat this, they recommend the use of a supported squat where the woman is supported under her arms allowing her to put less weight on her legs and feet, and her trunk to become longer, which can provide greater space for the fetus to move through the pelvis. Soong & Barnes (2005) found a significant increase in perineal trauma in women adopting the semi-recumbent position compared with the all fours position. These effects were more noticeable with women undergoing their first vaginal birth and where the birth weight was in excess of 3500 g. The use of the all fours position may be more comfortable for women who are labouring with the fetus in an occipito-posterior position.
Ragnar et al (2006) compared the use of kneeling and sitting upright and conclude that they do not differ significantly in their outcomes, although kneeling was associated with more favourable maternal experiences and reduced pain. It was considered that kneeling allowed women the freedom to modify their position more easily, thus allowing women to feel more in control.
Sutton (2003) suggests that pelvic diameters are increased when the woman adopts a lateral position. Soong & Barnes (2005) found that women with epidural anaesthesia were more likely to require suturing when they were in a semi-recumbent rather than a lateral position. Nicholl & Cattell (2006) support the use of a lateral position when delivery is undertaken on the bed as this helps to increase the number of intact perineums and reduce the incidence of fourth-degree tears.
Women should avoid excessive and prolonged knee holding (more likely in supine and semi-recumbent positions or prolonged squatting) as this can cause compressive peroneal neuropathy (functional and/or pathological changes to the peroneal nerve which supplies the calf and foot) which can present as knee tenderness, foot drop, decreased sensation over the dorsum of the foot (Sahai-Srivastava & Amezcua 2007).
Midwives can therefore:
• encourage and support women to adopt the positions of their choice in which they are most comfortable, while remembering the advantages of an upright position (or lateral where an epidural anaesthesia is present)
• teach women and their birthing partners how to utilise upright positions together
• have confidence in their own ability to facilitate safe deliveries in different positions.
It is important that delivery is an aseptic procedure for both the woman and the baby to reduce the incidence of postnatal infection. The midwife will use a sterile delivery pack, establishing a sterile field both on the working surface and in the area of the woman’s perineum. Adaptations are necessary according to the environment and the position that the woman has adopted. The midwife must attend to scrupulous hand hygiene and the use of all personal protective equipment including aprons, gowns, sterile gloves and eye protection (eye protection is sometimes interpreted as damaging the relationship with the woman but for certain delivery positions it should be considered). Once the sterile gloves have been applied for delivery they should be kept sterile or changed as needed. An anal pad may be used to cover or remove any faeces that may escape from the anus.
Management of the perineum
The HOOP Trial (McCandlish et al 1998) provides the means of giving women the choice as to how their perineum is managed. The hands-on approach – controlling the speed of delivery of the baby’s head, guarding of the perineum (placing the hand next to the perineum to support it) and applying traction to deliver the shoulders – demonstrated less perineal pain for women at 10 days after the birth. All other outcomes (e.g. perineal trauma) were similar, thus allowing women to make an informed choice. It is possible to achieve control of the speed of delivery with verbal guidance, but equally the woman may wish to deliver the baby herself onto her abdomen; both of these methods are modifications of the hands-on technique. NICE (2007) advises either technique can be used. Research into this aspect of care is ongoing and the reader needs to be aware of this.