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[md]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.

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[md]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.

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.

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.

''Obstetrics Handbook', Faculty of Medicine, University of Natal, 1984.[-3] Philpott RH, ''Obstetric Problems in the Developing World', Clinics in Obstetrics and Gynaecology 1982;9:3.[-3] ''The Partograph'. Section One, ''The Principle and Strategy'. Section Two, ''A user's manual'. 1988 Maternal and Child Health Unit, Division of Family Health. WHO Geneva. ARE YOU AND YOUR CLINICS USING PARTOGRAMS? Fig. 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. Fig. 18-2a SOME PARTOGRAMS. If you don't have enough partograms for every mother, put a clean sheet of X-ray film over one of them, write on this with a marker pencil, and then wash the film clean for the next patient.

Mother A, was admitted at 3 p.m. 4 cm dilated in the active phase of labour; her progress line remained to the left of the alert line and she delivered normally.

Mother B, was admitted at 9 a.m. 1 cm dilated; her latent phase lasted 8 hours and her active phase 3 hours.

Mother C, was admitted at 1 p.m. 1 cm dilated with her baby's head head 5/5 above the pelvic brim. At the next vaginal examination (5 p.m.) his head was 4/5 above the brim and she was 5 cm dilated. She was therefor transferred to the ''alert line''; her cervix continued to dilate, his head descended, and she delivered normally.

Mother D, was admitted to a health centre with her baby's head 4/5 above the brim and her cervix 3 cm dilated, so she was put on the alert line. At 12 midday she was only 6 cm dilated and had moved to the right of the alert line, so she was transferred to hospital. When she arrived at 4 p.m. she was still only 7 cm dilated and had reached the action line. His head was 3/5 above the brim, with a moulding score of 3; it was not posible to put a finger between his head and her pelvic wall, so, following the indications in Section 18.4, she was sectioned. Fig. 18-2b THE CRITICAL AREA IN A PARTOGRAM. 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!

THE GENERAL METHOD [s8]FOR DELAY IN LABOUR Here is the general method for delay in labour. If the presenting part has not only failed to descend, but there have also been these signs, labour is not only delayed, it is also obstructed: severe moulding and caput, fetal distress, a stretched lower segment, bloody urine, etc. If so, see Section 18.3.

DELAY [s7]IN THE LATENT PHASE (primips and multips) The latent phase is prolonged, if a patient who was ''admitted in labour' has not reached the active phase after 8 hours. First distinguish ''false labour' and a truly prolonged latent phase.

False labour: her membranes are still intact, a nullip's cervix remains long and closed (or just admits a finger tip), a multip's cervix is not effaced (even though it may be 1 or 2 cm dilated). Explain that she is not in labour, and send her home if she wishes. If she insists that she feels painful contractions give her pethidine 100 mg, let her sleep, and then discharge or review her.

Truly prolonged latent phase: Her cervix is completely effaced, but remains stationary at about 2 cm. Or it effaces and dilates very slowly. Either, (1) Sedate her with pethidine 100 mg, repeated if necessary, and wait. Or, (2) let her walk about. Or, (3) rupture her membranes and give her an oxytocin drip.

DELAY IN THE ACTIVE PHASE [s7]primips If a primip's progress line approaches the action line, she may have primary uterine inertia, or there may be some mechanical reason for it. Section her if: (1) She has gross CPD (head 4/5 above the brim and marked moulding). (2) A malpresentation (breech, transverse lie, face, or brow, etc.). (3) Fetal distress (M 20.4, M 21.3). If she has none of these things, manage her actively to decide if she has doubtful CPD, or no CPD. Manage her like this.

(1) Correct her dehydration and ketosis. Give her a drip of 5% dextrose.

(2) Provide adequate analgesia (A 2.9, M 18.15). Either give her a lumbar epidural block (A 7.2), or give her pethidine 100 mg and promethazine 25 mg, both intramuscularly.

(3) If you are sure she is in labour (that is her cervix is dilated 3 cm or more) and her membranes are not already ruptured, rupture them.

(4) Stimulate her uterus with oxytocin. Add 5 units of oxytocin to 500 ml of 5% dextrose, and start at 10 drops a minute. Increase the rate of the drip by 10 drops a minute at half-hourly intervals, until she is having contractions lasting 45 to 60 seconds at a frequency of 3 to 4 in 10 minutes. Make the first increment to 20 drops a minute, and half an hour later to 30 drops a minute. As soon as she has good contractions, don't increase the speed of the drip any more.

(5) Monitor her progress and her baby's condition carefully. Monitor his heart and watch for signs of fetal distress, especially slowing of the fetal heart (meconium staining of the liquor is common, and is an unreliable sign, M 20.5).

Decide how you are going to deliver her within 6 hours of starting the the oxytocin drip. Section her if any of these things happen, they are probably all signs of severe CPD: (1) There is fetal distress. (2) At the end of 6 hours she is still dilating less than 1 cm per hour, and the head is not descending. (3) It remains high, with moulding.

DELAY IN THE ACTIVE PHASE [s7]multips If a multip's progress line approaches the action line, this is serious, and you will need to assess her carefully. Don't try to stimulate her uterus with oxytocin, unless you are absolutely sure there is no CPD (see Section 18.4a). This is difficult to be sure about, and if you are wrong, and there is CPD, her uterus may rupture. One contributor advises no oxytocin for multips!

If she is in definite labour (her cervix is 3 cm or more) and her membranes have not already ruptured, rupture them.

If you are in doubt, observe her for 2 more hours with adequate analgesia, and then reassess her. Feel her contractions yourself. She may progress to full dilation even when there is major CPD. You can only detect this by finding severe moulding and caput, with failure of the head to descend, and delay (more than 20 minutes in the second stage).

CAUTION ! Some mothers have 6 or 8 normal labours, and then need section for CPD with their next pregnancy.

DIFFICULTIES [s7]WITH DELAY IN LABOUR If a patient is referred because of DELAY IN THE LATENT STAGE (M 20.7), look carefully for hidden CPD. If there is no CPD, rupture her membranes, and give her an oxytocin drip. Clinics should refer these cases, because CPD is not easy to recognize. Provided there is a vertex presentation, it is always worth rupturing the membranes and waiting a little to see what happens. CPD is almost impossible to diagnose when the membranes are intact.

If there is FETAL DISTRESS: if the is having an oxytocin drip, stop it; turn her onto her left side, do a vaginal examination to exclude prolapse of the cord, make sure she is she is adequately hydrated and give her oxygen.