18.3 Delay in labour

Labour is seldom any problem if it goes at its proper pace. Most trouble starts when it is delayed. If you are going to manage delay, you must know as early as possible that it has occurred. To know this you will need an effective method of monitoring labour—the partogram (or in WHO’s terminology, the ’partograph’) which Primary Mother Care describes in detail (M 18.2). The most important part of this is the ’cervicograph’ which plots the dilation of the cervix in centimetres, and the descent of the head in fifths above the brim, against the duration of labour in hours.

Figure 18.2: The partogram is a very useful tool for managing labour, but it will not help you to identify risk factors that may have been present before labour started. The vertical scale on the left measures the dilatation of the cervix in centimetres and the descent of the head in fifths above the brim.

The purpose of the partogram is: (1) To prevent obstructed labour and ruptured uterus (which cause 70% of maternal deaths in some areas) by enabling peripheral health workers to monitor labour, so as to detect deviations from the normal more effectively, and thus to refer mothers at the optimum moment—before it is too late. This is the purpose of the ’alert line’. Ideally, the partogram should only be used to monitor those labours which are expected to be normal; mothers with ’risk factors’ should have already been referred. (2) To monitor all labours in hospital, so that you know when to intervene. This is the purpose of the ’action line’. If the ’progress line’ of a mother’s cervical dilatation moves to the right of the alert line, be extra vigilant. If she reaches the action line you must do something, if you have not already done it (see below).

The partogram depends on the principles that: (1) The latent phase of labour should not last longer than 8 hours, hence the thick vertical line at this point. (2) The latent phase ends and the active phase starts when her cervix is 3 cm dilated (4 cm is sometimes used). (3) During the active phase her cervix should dilate at not less than 1 cm per hour. (4) A lag time of 4 hours is usually acceptable between the slowing of labour and the need to intervene; this is the distance between the alert and the action lines. The WHO partogram uses fixed alert and action lines and transfers her to the alert line as soon as she reaches 3 cm, as has been done for Mother C, in Fig. 18-2a.

Dilatation of the cervix and its relation to the action line is only one of the factors measuring the progress of labour, and the necessity to intervene. It and the descent of the baby’s head are the only two factors plotted on the cervicograph. Although they are the most useful and the most easily plotted ones, there are others which determine what you should do and when you should do it, they include: his presentation, his moulding score, his condition (fetal distress), his mother’s condition, and the strength and frequency of her contractions. Consider all these factors, and don’t be guided only by the dilatation of her cervix in relation to the action line and by the descent of his head, critical though these are.

Figure 18.3: The partogram is a very useful tool for managing labour, but it will not help you to identify risk factors that may have been present before labour started. The vertical scale on the left measures the dilatation of the cervix in centimetres and the descent of the head in fifths above the brim.

The position of the action line is to some extent arbitrary, and some obstetricians like the alert and action lines closer together. Intervention needs to be earlier in a multip than in a primip, so some partograms have two action lines, one at 3 hours for multips and one at 4 hours for primips. Some hospital partograms leave out the action line altogether and take the alert line as the action line. The important point is that the further the progress line is from the alert line, the greater should be your vigilance, and usually the greater your need to intervene. When, later, we say “If she approaches the action line, do ” what we really mean is that she has already crossed the alert line and is getting progressively nearer the action line (if your partogram has one). When is happening, assess all the factors listed above (and others) and decide what to do next, using the guidelines below and in Section 18.4.

Figure 18.4: In a peripheral unit, if a mother´s progress line reaches this area, she should be referred. In hospital, it is the area in which you should consider intervening; the darker the shading the more important this is. Don´t let her cross the action line!

Some hospitals consider that 1 cm per hour is ’too active’, and leads to an unnecessarily high Caesarean section rate, which is not suitable for populations with an average of perhaps 8 children, and when Caesarean section has to be done under less than ideal circumstances in small hospitals, so they give the alert line a flatter slope.

Partograms have proved so useful in reducing both maternal and perinatal mortality, that not to introduce them might almost be considered criminal neglect. If you don’t already use them, you must! There is full–size copy on an endpaper, and also an interim version of the the other side. A further version of this will be included in Primary Mother Care.