Prepared participatory childbirth

In this approach the parents undertake childbirth training, learning about the processes of childbirth and how to accept the pains of uterine contractions (see pp. 49–50). Labour is managed by trained staff, and the principles mentioned earlier are observed by both staff and patients. The birth takes place in a quiet environment and the baby is given to the mother at once so that she may offer suckling and celebrate the birth.

Women can have a prepared participatory childbirth in a normal hospital delivery room, but for some it is more satisfactory if there is a birthing centre.

Actively managed childbirth

The development of the partogram and the appreciation that most women have delivered within 12 hours of admission to hospital has led to another approach: actively managed labour.

On admission to the delivery unit, the diagnosis of labour is either confirmed or rejected. If the woman is in labour, the time of admission is designated as the start of labour. A partogram is started and the progress of labour is marked on it (Fig. 8.1). Vaginal examinations are made every 2–4 hours and the cervical dilatation is recorded on the partogram. Action lines, printed on transparent plastic, are superimposed on the partogram (Fig. 8.2). In the active stage of labour the slowest acceptable rate of cervical dilatation is 1 cm/h. If the cervical dilatation lies to the right of the appropriate action line the membranes are ruptured and an incremental dilute oxytocin infusion is established in nulliparous women (and some multiparous women), provided that a single fetus presents as a vertex and there are no signs of fetal distress.

Fig. 8.1 A partogram.

Fig. 8.2 Action lines for the partogram (Studd stencil). The lines show the slowest acceptable rate of cervical dilatation, commencing with the degree of dilatation on admission to the delivery unit.

Progress in the second stage of labour is judged by the descent of the fetal head and its rotation. One hour is allowed for the fetal head to reach the pelvic floor (the first or passive phase) and a further hour for the birth to be completed (the second or active phase). If there is delay in the passive phase then oxytocic augmentation is instituted. Delay in the active phase dictates close fetal monitoring and, where indicated, an operative vaginal delivery. Proponents of actively managed labour claim that the incidence of a labour lasting more than 12 hours is less than 3%; the caesarean section rate is 7–12% and the forceps rate is 8%. Opponents point out that only three randomized studies have been carried out, and that in these studies there was no reduction in the caesarean section or forceps rate.

Elective caesarean section

A small but increasing number of women, particularly those over the age of 35, inform their obstetrician during pregnancy that they wish to be delivered by caesarean section. The obstetrician should listen to the woman and discern the underlying reasons for her request. For some it may be a fear of the pain of labour, for others to avoid any risk of pelvic floor damage during delivery, or a perception that abdominal delivery removes all risks for the baby. It is particularly important that the risks of caesarean versus vaginal delivery are carefully explained (Box 8.3). If the woman confirms that she wishes to be delivered by caesarean section, the obstetrician should either agree to her wish or arrange for a consultation with another colleague.

Home birth

Women choosing this type of delivery must receive good prenatal care; must be screened for any medical or obstetric abnormality; must accept transferral to a hospital if an abnormality arises during pregnancy or childbirth; and must have an experienced midwife. Even then home birth is less safe than giving birth in a midwife-controlled birthing centre.

False labour

As term approaches many women complain of painful uterine contractions, which may seem to indicate the onset of labour. However, despite the contractions, progressive dilatation of the cervix fails to occur – this condition is termed false labour.

In it, the triple descending gradient of uterine activity fails to become established. A reverse gradient of uterine activity is present, the lower part of the uterus contracting nearly as strongly as the upper part. Because of this, cervical dilatation fails to occur and the pain of the uterine contractions is often felt as low backache.

Clinically, the painful contractions occur more often at night, but their frequency and intensity do not increase as time passes. A woman who complains of this pattern of uterine activity needs an explanation and, if the pains are distressing, requires treatment with analgesics, and perhaps a hypnotic so that she can enjoy a good night’s sleep.

Often the pains of false labour recur on a number of days and, in some cases, the reverse gradient of activity changes and true labour starts.

Onset of true labour

True labour may start and progress rapidly, or the start may be slow, with contractions only occurring at long intervals – the so-called sluggish uterus, or, in a more modern idiom, prolongation of the quiet (latent) phase of labour.

If the woman is becoming distressed that labour is not progressing, a more effective pattern of uterine activity can be obtained by performing an amniotomy and by starting an intravenous infusion of oxytocin. This regimen should only be instituted if there is no cephalopelvic disproportion and if the cervix is partly or wholly effaced, 2 cm dilated and soft.

The onset of labour is difficult to time with any degree of accuracy, and may be heralded by the following signs:

The transition into labour is gradual, but labour may be said to have begun when the cervix is at least 2 cm dilated and contractions become painful and regular, with diminishing intervals between each one.

Because of the difficulty in establishing the time of onset of labour with any degree of accuracy, many obstetricians mark its onset from the time the woman is admitted to hospital. This has advantages if the graphic method of recording the progress of labour (the partogram) is adopted.

Duration of labour

The duration of labour is not easy to determine precisely as its onset is often indefinite and subjective (Box 8.4). In studies of informed women whose labour started spontaneously there was a wide variation in the duration of labour, as can be seen in Table 8.1.

Table 8.1 Duration (and range) of labour (in hours)

Labour is usually shorter when the patient knows something of the physiology of normal labour, is in good physical and mental health at the onset of labour, and has confidence in her attendants. Delivery within 16 hours may be expected in 90% of nulliparous women (para 0), and the same proportion of multiparous women (para 1+) will deliver within 12 hours.

Admission

On admission the woman’s antenatal records are obtained and scrutinized for any past medical or obstetric problems, to check the history of the current pregnancy, and to make sure that the appropriate laboratory tests have been made. A history of the present labour is obtained, the frequency and strength of the uterine contractions are noted, and information is obtained about a ‘show’ of blood or mucus and whether or not the membranes have broken.

A general examination is made by a midwife or a doctor, the blood pressure, pulse and temperature being recorded. The abdomen is palpated to determine the presentation of the fetus and the position of the presenting part in relation to the pelvic brim (see Fig. 6.17). A vaginal examination may be carried out, with aseptic precautions, to determine the effacement and dilatation of the cervix and the position and station of the presenting part. The station of the presenting part is the level of the lowest fetal bony part (head or breech) in relation to an imaginary line joining the mother’s ischial spines. It is measured in centimetres above or below the ischial spines (Fig. 8.3). If the amniotic sac (the membranes) has ruptured this is noted. Evidence does not support the common practice of performing a routine 20-minute cardiotocogram (CTG) on admission in low-risk women. The ‘admission CTG’ is associated with higher intervention rates, i.e. augmentation of labour, epidural analgesia and operative delivery, without a clear improvement in neonatal outcome. The woman is transferred from the admission room to a bed in a delivery room (if she has not already been admitted to it) and a partogram is started which shows the progress of labour at a glance.

Fig. 8.3 Station of the head.

First stage of labour