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Intrapartum Care: Monitoring the condition of the fetus during the first stage of labour

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Intrapartum Care was developed for doctors and advanced midwives who care for women who deliver in district hospitals. It contains theory chapters and skills workshops adapted from the labour chapters …

Intrapartum Care was developed for doctors and advanced midwives who care for women who deliver in district hospitals. It contains theory chapters and skills workshops adapted from the labour chapters of Maternal Care. Monitoring the mother, fetus, and progress of labour, the second and third stages of labour, managing pain, the puerperium and family planning

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  • 1. 2 Monitoring the condition of the fetus during the first stage of labourBefore you begin this unit, please take the MONITORING THE FETUScorresponding test at the end of the book toassess your knowledge of the subject matter. Youshould redo the test after you’ve worked through 2-1 Why should you monitorthe unit, to evaluate what you have learned the fetus during labour? It is essential to monitor the fetus during Objectives labour in order to assess the response to the stresses of labour. The stress of a normal labour usually has no effect on a healthy fetus. When you have completed this unit you should be able to: 2-2 What may stress the • Monitor the condition of the fetus fetus during labour? during labour. 1. Compression of the fetal head during • Record the findings on the partogram. contractions. • Understand the significance of the 2. A decrease in the supply of oxygen to the findings. fetus. • Understand the causes and signs of fetal 2-3 How does head compression distress. stress the fetus? • Interpret the significance of different fetal heart rate patterns and meconium- Uterine contractions may compress the fetal head and cause slowing of the fetal heart rate. stained liquor. Head compression usually does not harm the • Manage any abnormalities which are fetus. detected. NOTE Slowing of the fetal heart is due to vagal stimulation. With a long labour due to cephalopelvic disproportion, compression
  • 2. MONITORING THE CONDITION OF THE FETUS DURING THE FIRST STAGE OF LABOUR 25 of the fetal head can be severe and 2-6 When do uterine contractions reduce repeated. This may result in fetal distress. the supply of oxygen to the fetus? Usually uterine contractions do not reduce2-4 What may reduce the supply the supply of oxygen to the fetus, as there is anof oxygen to the fetus? adequate store of oxygen in the placental blood1. Uterine contractions: Uterine contractions to meet the fetal needs during the contraction. are the commonest cause of a decrease Normal contractions in labour do not affect in the oxygen supply to the fetus during the healthy fetus with a normally functioning labour. placenta, and, therefore, are not dangerous.2. Abnormal uterine blood vessels: The However, contractions may reduce the oxygen placenta may fail to provide the fetus with supply to the fetus when: enough oxygen and nutrition due to a decrease in the blood flow through the 1. There is placental insufficiency. uterine blood vessels to the placenta, i.e. 2. The contractions are prolonged or very placental insufficiency. Women with pre- frequent. eclampsia have poorly formed, narrow 3. There is compression of the umbilical cord. spiral arteries that provide inadequate amounts of maternal blood to the 2-7 How does the fetus respond placenta. Maternal smoking can also cause to a lack of oxygen? narrowing of the uterine blood vessels. A reduction in the normal supply of oxygen to3. Abruptio placentae: Part or all of the the fetus causes fetal hypoxia. This is a lack of placenta stops functioning because it oxygen in the cells of the fetus. If the hypoxia is separated from the uterine wall by a is mild the fetus will be able to compensate retroplacental haemorrhage. There is also and, therefore, show no response. However, spasm of the uterus which reduces the severe fetal hypoxia will result in fetal distress. amount of maternal blood reaching the Severe, prolonged hypoxia will eventually placenta. As a result the fetus does not result in fetal death. receive enough oxygen.4. Cord prolapse or compression: This stops the fetal blood flow and transport of 2-8 How is fetal distress oxygen from the placenta to the fetus. recognised during labour? Fetal distress caused by a lack of oxygen results Uterine contractions are the commonest cause in a decrease in the fetal heart rate. The fetus responds to hypoxia with a bradycardia to of a decreased oxygen supply to the fetus conserve oxygen. during labour. 2-9 How do you assess the condition2-5 How do contractions reduce the of the fetus during labour?supply of oxygen to the fetus? Two observations are used:Uterine contractions may: 1. The fetal heart rate pattern.1. Reduce the maternal blood flow to the 2. The presence or absence of meconium in placenta due to the increase in intra- the liquor. uterine pressure.2. Compress the umbilical cord.
  • 3. 26 INTRAPAR TUM CAREFETAL HEART RATE 2-12 How often should you monitor the fetal heart rate?PATTERNS Low risk patients who have had normal observations on admission:2-10 What devices can be used to 1. Two hourly during the latent phase ofmonitor the fetal heart rate? labour.Any one of the following three pieces of 2. Half hourly during the active phase ofequipment: labour.1. A fetal stethoscope. Women with a high risk of fetal distress should2. A ‘doptone’ (Doppler ultrasound fetal heart have their observations done more frequently. rate monitor). The following women would be regarded as at3. A cardiotocograph (CTG machine). higher risk:In most low risk labours the fetal heart rate is 1. Intermediate risk patients.determined using a fetal stethoscope. However, 2. High risk patients.a doptone is helpful if there is difficulty 3. Patients with abnormal observations onhearing the fetal heart, especially if distress or admission.intra-uterine death is suspected. If available, 4. Patients with meconium-stained liquor.a doptone is the preferred method in primary These women need more frequent recording ofcare clinics and hospitals. Cardiotocograph the fetal heart rate:is not needed in most labours but is animportant and accurate method of monitoring 1. Hourly during the latent phase of labour.the fetal heart in high risk pregnancies. 2. Half hourly during the active phase of labour. 3. At least every 15 minutes if fetal distress is A doptone is the preferred method of assessing suspected. the fetal heart rate in primary care clinics and hospitals. 2-13 What features of the fetal heart rate pattern should you2-11 How should you monitor always assess during labour?the fetal heart rate? There are two features that should always beBecause uterine contractions may decrease assessed:the maternal blood flow to the placenta, and 1. The baseline fetal heart rate: This is thethereby cause a reduced supply of oxygen to heart rate between contractions.the fetus, it is essential that the fetal heart rate 2. The presence or absence of decelerations: Ifshould be monitored during a contraction. In present, the relation of the deceleration topractice, this means that the fetal heart pattern the contraction must be determined:must be checked before, during and after the • Decelerations that occur only during acontraction. A comment on the fetal heart contraction (i.e. early decelerations).rate, without knowing what happens during • Decelerations that occur duringand after a contraction, is almost valueless. and after a deceleration (i.e. late decelerations) The fetal heart rate must be assessed before, • Decelerations that have no fixed relation to contractions (i.e. variable during, and after a contraction. decelerations).
  • 4. MONITORING THE CONDITION OF THE FETUS DURING THE FIRST STAGE OF LABOUR 27 NOTE In addition, the variability of the fetal heart 2-16 What are early decelerations? rate can also be evaluated if a cardiotocograph is available. Good variability gives a spiky trace Early decelerations are characterised by a while poor variability gives a flat trace. slowing of the fetal heart rate starting at the beginning of the contraction, and returning2-14 What fetal heart rate patterns to normal by the end of the contraction. Earlycan be recognised with a fetal decelerations are usually due to compressionstethoscope or doptone? of the fetal head which causes the heart rate to slow during the contraction.1. Normal.2. Early deceleration. 2-17 What is the significance3. Late deceleration. of early decelerations?4. Variable deceleration.5. Baseline tachycardia. Early decelerations do not indicate the6. Baseline bradycardia. presence of fetal distress. However, these fetuses must be carefully monitored as they areThese fetal heart rate patterns (with the at an increased risk of fetal distress.exception of variable decelerations) canbe easily recognised with a stethoscope NOTE When early decelerations are seen on aor doptone. However, cardiotocograph CTG trace, normal variability of the fetal heartrecordings (figures 2-1, 2-2 and 2-3) are rate is reassuring that the fetus is not hypoxic.useful in learning to recognise the differencesbetween the three types of deceleration. 2-18 What are late decelerations?It is common to get a combination of A late deceleration is a slowing of the fetalpatterns, e.g. a baseline bradycardia with late heart rate during a contraction, with the ratedecelerations. It is also common to get one only returning to the baseline 30 seconds orpattern changing to another pattern with more after the contraction has ended.time, e.g. early decelerations becoming latedecelerations. With a late deceleration the fetal heart rate only NOTE The variation in fetal heart rate normally returns to the baseline 30 seconds or more after exceeds five beats or more per minute, giving the contraction has ended. the baseline a spiky appearance on a CTG trace. A loss or reduction in beat-to-beat variation to below five beats per minute gives NOTE When using a cardiotocograph, a late a flat baseline (a ‘flat trace’) which suggests deceleration is diagnosed when the lowest fetal distress. However a flat baseline may also point of the deceleration occurs 30 seconds occur if the fetus is asleep or as the result of or more after the peak of the contraction. the administration of analgesics (pethidine, morphine) or sedatives (phenobarbitone). 2-19 What is the significance of late decelerations?2-15 What is a normal fetal Late decelerations are a sign of fetal distressheart rate pattern? and are caused by fetal hypoxia. The degree to1. No decelerations during or after which the heart rate slows is not important. It is contractions. the timing of the deceleration that is important.2. A baseline rate of 100 – 160 beats per minute. Late decelerations indicate fetal distress.
  • 5. 28 INTRAPAR TUM CAREFigure 2-1: An early deceleration Figure 2-2: A late deceleration2-20 What are variable decelerations? 2-22 What are the causes of aVariable decelerations have no fixed baseline tachycardia?relationship to uterine contractions. Therefore, 1. Maternal pyrexia.the pattern of decelerations changes from one 2. Maternal exhaustion.contraction to another. Variable decelerations 3. Hexoprenaline (Ipradol) administration.are usually caused by compression of the 4. Chorioamnionitis (infection of theumbilical cord and do not indicate the placenta and membranes).presence of fetal distress. However, these 5. Fetal haemorrhage or anaemia.fetuses must be carefully monitored as they areat an increased risk of fetal distress. There is an increased risk of fetal distress if a fetal tachycardia is present.Variable decelerations are not easy torecognise with a fetal stethoscope or doptone. 2-23 What is a baseline bradycardia?They are best detected with a cardiotocograph. A baseline fetal heart rate of less than 100 NOTE Variable decelerations accompanied by beats per minute. loss of variability of the fetal heart rate may indicate fetal distress. Variable decelerations 2-24 What is the cause of a with good variability is reassuring. baseline bradycardia?2-21 What is a baseline tachycardia? A baseline bradycardia of less than 100 beats per minute usually indicates fetal distressA baseline fetal heart rate of more than 160 which is caused by severe fetal hypoxia. Ifbeats per minute. decelerations are also present, a baseline bradycardia indicates that the fetus is at great risk of dying.
  • 6. MONITORING THE CONDITION OF THE FETUS DURING THE FIRST STAGE OF LABOUR 29 These fetal heart rate patterns do not indicate fetal distress but warn that the fetal heart rate must be closely observed as fetal distress may develop. If electronic monitoring (a cardiotocograph) is available, the fetal heart rate pattern must be monitored. 2-28 What fetal heart rate patterns indicate fetal distress during labour? 1. Late decelerations. 2. A baseline bradycardia. NOTE On cardiotocography loss of variability of the fetal heart rate lasting more than 60 minutes also suggests fetal distress. 2-29 How should the fetal heart rate pattern be observed during labour?Figure 2-3: Variable decelerations The fetal heart rate must be observed before, during and after a contraction. The following questions must be answered and recorded on2-25 How should you assess the the partogram:condition of the fetus on the basisof the fetal heart rate pattern? 1. What is the baseline fetal heart rate? 2. Are there any decelerations?1. The fetal condition is normal if a normal 3. If decelerations are observed, what is their fetal heart rate pattern is present. relation to the uterine contractions?2. The fetal condition is uncertain if the fetal 4. If the fetal heart rate pattern is abnormal, heart rate pattern indicates that there is an how must the patient be managed? increased risk of fetal distress.3. The fetal condition is abnormal if the fetal 2-30 Which fetal heart rate pattern heart rate pattern indicates fetal distress. indicates that the fetal condition is good?2-26 What is a normal fetal heart 1. The baseline fetal heart rate is normal.rate pattern during labour? 2. There are no decelerations.A normal baseline fetal heart rate without anydecelerations.2-27 Which fetal heart rate patternsindicate an increased risk of fetaldistress during labour?1. Early decelerations.2. Variable decelerations.3. A baseline tachycardia.
  • 7. 30 INTRAPAR TUM CAREFigure 2-4: Recording fetal observations on the partogramMANAGING A WOMAN and stop the oxytocin infusion to prevent uterine overstimulation.WITH AN ABNORMAL 2. If the fetal bradycardia persists, intra-FETAL HEART uterine resuscitation of the fetus must be given and the fetus delivered as quick asRATE PATTERN possible. 2-33 How is fetal resuscitation given?2-31 What must be done ifdecelerations are observed? 1. Turn the woman onto her side. 2. Give her 40% oxygen through a face mask.First the relation of the decelerations to the 3. Start an intravenous infusion of Ringer’suterine contractions must be observed to lactate and give 250 μg (0.5 ml) salbutamoldetermine the type of deceleration. Then (Ventolin) slowly intravenously, aftermanage the patient as follows: ensuring that there is no contraindication1. If the decelerations are early or variable, to its use. (Contraindications to salbutamol the fetal heart rate pattern warns that are heart valve disease, a shocked patient there is an increased risk of fetal distress or patient with tachycardia). The 0.5 ml and, therefore, the fetal heart rate must be salbutamol is diluted with 9.5 ml sterile checked every 15 minutes. water and given slowly intravenously over2. If late decelerations are present, the five minutes. management will be the same as the 4. Deliver the infant by the quickest possible management of fetal bradycardia. route. If the woman’s cervix is 9 cm or more dilated and the head is on the pelvicThe observations of the fetal heart rate must floor, proceed with an assisted deliverybe recorded on the partogram as shown in (forceps or vacuum). Otherwise, perform afigure 2-4. A note of what management is Caesarean section.decided upon must also be made under the 5. If the patient cannot be deliveredheading ‘Management’ at the bottom of the immediately (i.e. there is another patientpartogram. in theatre) the dose of salbutamol can be repeated if contractions start again, but not2-32 What must be done if a fetal within 30 minutes of the first dose or if thebradycardia is observed? maternal pulse is 120 or more beats perFetal distress due to severe hypoxia is present! minutes.Therefore, you should immediately do the It is important that you know how to give fetalfollowing: resuscitation, as it is a life-saving procedure when fetal distress is present, both during the1. Exclude other possible causes of antepartum period and in labour. bradycardia, e.g. turn the woman onto her side to correct supine hypotension,
  • 8. MONITORING THE CONDITION OF THE FETUS DURING THE FIRST STAGE OF LABOUR 31Always prepare to resuscitate the infant after distress may be present. If not, the fetus isbirth if fetal distress is diagnosed during labour. at high risk of distress. 2. There is a danger of meconium aspiration NOTE Salbutamol (a beta2 stimulant) can also at delivery. be given from an inhaler but this method is less effective than the parenteral administration. Give four puffs from a salbutamol inhale. This Meconium-stained liquor warns that either fetal can be repeated every 10 minutes until the distress is present or that there is a high risk of uterine contractions are reduced in frequency fetal distress. and duration, or the maternal pulse reaches 120 beats per minute. Uterine contractions can also be suppressed with nifedipine (Adalat). Nifedipine 2-37 How should you monitor the 30 mg is given by mouth (one capsule = 10 mg). fetus during the first stage of labour The three capsules must be swallowed and not if the liquor is meconium stained? used sublingually. This method is slower than using intravenous salbutamol and the uterine 1. Observe carefully for late decelerations. contractions will only be reduced after 20 minutes. If present, then fetal distress must be diagnosed. 2. If late decelerations are absent, thenTHE LIQUOR observe the fetal heart rate pattern carefully during labour as about a third of fetuses with meconium-stained liquor will2-34 Is the liquor commonly develop fetal distress.meconium-stained? 3. If electronic monitoring (CTG) is available,Yes, in 10–20% of patients the liquor is yellow the fetal heart rate pattern must beor green due to meconium staining. The carefully monitored.incidence of meconium-stained liquor isincreased in the group of women that go into 2-38 How must the delivery be managedlabour after 42 weeks gestation. if there is meconium in the liquor? 1. The infant’s mouth and pharynx must2-35 Is it important to distinguish be thoroughly suctioned after deliverybetween thick and thin, or yellow of the head but before the shouldersand green meconium? and chest are delivered, i.e. before theAlthough fetal and neonatal complications infant breathes. This must be doneare more common which thick meconium, irrespective of whether a vaginal deliveryall cases of meconium-stained liquor should or Caesarean section is done.be managed the same during the first stage 2. Anticipate that the infant may need to beof labour. The presence of meconium is resuscitated at delivery. If the infant criesimportant and the management does not or breathes well no further suctioning isdepend on the consistency of the meconium. needed. However if the infant does not cry well, suction the infant again before starting mask ventilation. If intubation is2-36 What is the importance of needed, suction via the endotracheal tubemeconium in the liquor? before starting ventilation.1. Meconium-stained liquor usually indicates the presence of fetal hypoxia or an episode 2-39 How and when are the of fetal hypoxia in the past. Therefore, fetal liquor findings recorded? Three symbols are used to record the liquor findings on the partogram:
  • 9. 32 INTRAPAR TUM CAREI = Intact membranes (i.e. no liquor draining). late decelerations, labour may be allowed to continue. However, very careful observationC = Clear liquor draining. of the fetal heart rate pattern is essential,M = Meconium-stained liquor draining. especially if oxytocin is to be restarted. The fetal heart should be listened to every 15The findings are recorded in the appropriate minutes or fetal heart rate monitoring with aspace on the partogram as shown in figure 2-4. cardiotocograph should be started.The liquor findings should be recorded when:1. The membranes rupture.2. A vaginal examination is done. CASE STUDY 23. A change in the liquor findings is noticed, e.g. if the liquor becomes meconium A woman who is 38 weeks pregnant presents stained. with an antepartum haemorrhage in labour. On examination, her temperature is 36.8 °C, her pulse rate 116 beats per minute, herCASE STUDY 1 blood pressure 120/80 mm Hg, and there is tenderness over the uterus. The baselineA primigravida with inadequate uterine fetal heart rate is 166 beats per minute. Thecontractions during labour is being treated fetal heart rate drops to 130 beats per minutewith an oxytocin infusion. She now has during contractions and then only returns tofrequent contractions, each lasting more than the baseline 35 seconds after the contraction40 seconds. With the woman in the lateral has ended.position, listening to the fetal heart rate revealslate decelerations. 1. Which of the maternal observations are abnormal and what is the probable1. What worries you most cause of these abnormal findings?about this woman? A maternal tachycardia is present and there isThe late decelerations indicate that fetal uterine tenderness. These findings suggest andistress is present. abruptio placentae.2. Should the fetus be 2. Which fetal observations are abnormal?delivered immediately? Both the baseline tachycardia and the lateNo. Correctable causes of poor oxygenation of decelerations.the fetus must first be ruled out, e.g. posturalhypotension and overstimulation of the uterus 3. How can you be certain thatwith oxytocin. The oxytocin infusion must these are late decelerations?be stopped and oxygen administered to thewoman. Then the fetal heart rate should be Because the deceleration continues forchecked again. more than 30 seconds after the end of the contraction. This observation indicates fetal distress. The number of beats by which the3. After stopping the oxytocin the fetal heart slows during a deceleration is notuterine contractions are less frequent. important.No further decelerations of the fetalheart rate are observed. What furthermanagement does this patient need?As overstimulation of the uterus withoxytocin was the most likely cause of the
  • 10. MONITORING THE CONDITION OF THE FETUS DURING THE FIRST STAGE OF LABOUR 334. Why should an abruptio 3. How would you decide whetherplacentae cause fetal distress? this fetus is distressed?Part of the placenta has been separated from By listening to the fetal heart rate. Latethe wall of the uterus by a retroplacental clot. decelerations or a baseline bradycardia willAs a result, the fetus has become hypoxic. indicate fetal distress. 4. How should the fetus be monitoredCASE STUDY 3 during the remainder of the labour? The fetal heart rate pattern must beDuring the first stage of labour a woman’s liquor determined carefully every 15 minutes in orderis noticed to have become stained with thin to diagnose fetal distress should this occur.green meconium. The fetal heart rate pattern isnormal and labour is progressing well. 5. What preparations should be made for the infant at delivery?1. What is the importance of thechange in the colour of the liquor? The infant’s mouth and pharynx must be well suctioned immediately after the head has beenMeconium in the liquor indicates an episode delivered. No further suctioning is neededof fetal hypoxia and suggests that there may be if the infant cries or breathes well. However,fetal distress or that the fetus is at high risk of if the infant does not breathe well directlyfetal distress. after delivery, suctioning should be repeated before mask ventilation is started. If the infant2. Can thin meconium be a is intubated, further suctioning of the largersign of fetal distress? airways via the endotracheal tube should beYes. All meconium in the liquor indicates either done before ventilation is started.fetal distress or that the fetus is at high risk offetal distress. The management does not dependon whether the meconium is thick or thin.

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