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Maternal Care: Preterm labour and preterm rupture of the membranes
 

Maternal Care: Preterm labour and preterm rupture of the membranes

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Maternal Care addresses all the common and important problems that occur during pregnancy, labour, delivery and the puerperium. It covers: the antenatal and postnatal care of healthy women with normal ...

Maternal Care addresses all the common and important problems that occur during pregnancy, labour, delivery and the puerperium. It covers: the antenatal and postnatal care of healthy women with normal pregnancies, monitoring and managing the progress of labour, specific medical problems during pregnancy, labour and the puerperium, family planning, regionalised perinatal care

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    Maternal Care: Preterm labour and preterm rupture of the membranes Maternal Care: Preterm labour and preterm rupture of the membranes Document Transcript

    • 5 Preterm labour and preterm rupture of the membranesBefore you begin this unit, please take the PRETERM LABOUR ANDcorresponding test at the end of the book toassess your knowledge of the subject matter. You PRETERM RUPTURE OFshould redo the test after you’ve worked through THE MEMBRANESthe unit, to evaluate what you have learned. 5-1 What is preterm labour? Objectives Preterm labour is diagnosed when there are regular uterine contractions before 37 weeks of When you have completed this unit you pregnancy, together with either of the following: should be able to: 1. Cervical effacement and/or dilatation. • Define preterm labour and preterm 2. Rupture of the membranes. rupture of the membranes. • Understand why these conditions are 5-2 What is preterm rupture very important. of the membranes? • Understand the role of infection in Preterm rupture of the membranes is diagnosed causing preterm labour and preterm when the membranes rupture before 37 weeks, rupture of the membranes. in the absence of uterine contractions. • List which patients are at increased risk NOTE Preterm rupture of the membranes (as of these conditions. defined above) is sometimes called preterm, • Understand what preventive measures prelabour rupture of the membranes in literature. should be taken. • Diagnose preterm labour and preterm 5-3 What is prelabour rupture rupture of the membranes. of the membranes? • Manage these conditions. Prelabour rupture of the membranes is defined as rupture of the membranes for at least one hour before the onset of labour in a term pregnancy.
    • 118 MATERNAL CARE5-4 How should you diagnose preterm membranes and placenta. Later these bacterialabour if the gestational age is unknown? may colonise the liquor, from where they may infect the fetus.Preterm labour is diagnosed if the estimatedfetal weight is below 2500 g. The symphysis- Chorioamnionitis may cause the releasefundus height will be less than 35 cm. of prostaglandins which in turn stimulate uterine contractions and cause the onset of5-5 Why are preterm labour and preterm labour. Chorioamnionitis may also weaken therupture of the membranes important? membranes and lead to their rupture. If the membranes have already been ruptured due toPreterm labour and preterm rupture of the other causes, such as polyhydramnios, vaginalmembranes are major causes of perinatal bacteria can spread directly into the liquor. Thedeath because: longer the duration of ruptured membranes, the1. Preterm delivery, especially before 34 weeks, greater the risk of chorioamnionitis. The risk commonly results in the birth of an infant of infection is also increased by digital vaginal who develops hyaline membrane disease examinations after rupture of the membranes. and other complications of prematurity.2. Preterm labour and preterm rupture of NOTE After delivery, the diagnosis of chorioamnionitis can be confirmed by: the membranes are often accompanied by bacterial infection of the membranes and • Noting that the infant and placenta placenta that may cause complications for have an offensive smell. both the mother and the fetus. The mother • Noting that the membranes are cloudy. and fetus may develop severe infection, • Finding pus cells and bacteria on which is life threatening microscopic examination of the infant’s gastric aspirate immediately after birth.5-6 What is the commonest known • Finding acute inflammation in the membranescause of preterm labour and preterm and placenta on histology after delivery.rupture of the membranes?In many cases the cause is unknown, but Infection of the membranes and placentaincreasing evidence points to infection of the (chorioamnionitis) may occur with either intactmembranes and placenta as the commonest or ruptured membranes.known cause of both preterm labour andpreterm rupture of the membranes. 5-8 What is the clinical presentation of chorioamnionitis? Infection of the membranes and placenta is the Usually chorioamnionitis is asymptomatic commonest recognised cause of preterm labour (subclinical chorioamnionitis) and, therefore, and preterm rupture of the membranes. the clinical diagnosis is often not made. However, the following signs may be present:5-7 What is infection of the 1. Fetal tachycardia.membranes and placenta? 2. Maternal pyrexia and/or tachycardia.Infection of the membranes and placenta 3. Tenderness of the uterus.causes an acute inflammation of the placenta, 4. Drainage of offensive liquor, if themembranes and decidua. This condition is membranes have ruptured.called chorioamnionitis. It may occur with If any of the above signs are present, a diagnosisintact or ruptured membranes. of clinical chorioamnionitis must be made.Bacteria from the cervix and vagina spreadthrough the endocervical canal to infect the
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 119 NOTE There is no proof that daily white cell 2. Fetal factors: counts or determination of C-reactive protein • A multiple pregnancy. (CRP) are of any greater diagnostic value in • Polyhydramnios (both cause making an early diagnosis of chorioamnionitis. overdistension of the uterus.) • Congenital malformations of the fetus.5-9 What factors may predispose • Syphilis.a woman to chorioamnionitis? 3. Placental factors:1. Rupture of the membranes. • Placenta praevia.2. Exposure of the membranes due to • Abruptio placentae. dilatation of the cervix. NOTE Polyhydramnios, multiple pregnancy and3. Coitus during the second half of cervical incompetence cause preterm dilatation pregnancy. of the cervix with exposure of the membranesHowever, in many cases, the factors that result to the vaginal bacteria. This may predisposein chorioamnionitis are not known. to chorioamnionitis. Polyhydramnios has several causes, but it is important to remember that oesophageal atresia is one of the causes5-10 Can chorioamnionitis cause which need to be excluded after delivery.complications during the puerperium?Yes. Chorioamnionitis may cause infection of 5-12 Which patients are at an increasedthe genital tract (puerperal sepsis) which, if risk of preterm labour or pretermnot treated correctly, may result in septicaemia, rupture of the membranes?the need for hysterectomy, and possibly in Both preterm labour and preterm rupture ofmaternal death. These complications can membranes are more common in patients who:usually be prevented by starting a course ofbroad spectrum antibiotics (e.g. ampicillin plus 1. Have a past history of preterm labour.metronidazole), as soon as the diagnosis of 2. Have no antenatal care.clinical chorioamnionitis is made. 3. Live in poor socio-economic circumstances.Bacteria that have colonised the amniotic fluid 4. Smoke, use alcohol or abuse habit-formingmay infect the fetus, and the infant may present drugs.with signs of infection at, or soon after, birth. 5. Are underweight due to undernutrition. 6. Have coitus in the second half of5-11 What factors other than chorio- pregnancy, when they are at an increasedamnionitis can lead to preterm labour and risk of preterm labourpreterm rupture of the membranes? 7. Have any of the maternal, fetal or placentalThe following maternal, fetal and placental factors listed in 5-11.factors may be associated with preterm labourand/or preterm rupture of the membranes: The most important risk factor for preterm labour is a previous history of preterm delivery.1. Maternal factors: • Pyrexia, as the result of an acute infection other than chorioamnionitis, 5-13 What can be done to decrease the e.g. acute pyelonephritis or malaria. incidence of these complications? • Uterine abnormalities, such as 1. Take measures to ensure that all pregnant congenital uterine malformations women receive antenatal care. (e.g. septate or bicornuate uterus) and 2. Identify patients with a past history of uterine myomas (fibroids). preterm labour. • Incompetence of the internal cervical 3. Give advice about the dangers of smoking, os (‘cervical incompetence’). alcohol and the use of habit-forming drugs.
    • 120 MATERNAL CARE4. Advise against coitus during the late second All patients should be told to immediately and in the third trimester in pregnancies report preterm labour or preterm rupture of the at high risk for preterm labour or preterm rupture of the membranes. If coitus occurs membranes. during pregnancy in these patients, the use of condoms must be recommended as this 5-15 What should you do if a patient may reduce the risk of chorioamnionitis. threatens to deliver a preterm infant?5. At 14–16 weeks, insert a McDonald suture 1. Infants born between 34 and 36 weeks can in patients with a proven incompetent usually be cared for in a level 1 hospital. internal cervical os. 2. However, women who deliver between 286. Prevent teenage pregnancies. and 33 weeks, should be referred to a level7. Improve the socio-economic and 2 or 3 hospital with a neonatal intensive nutritional status of poor communities. care unit.8. Arrange that the workload of women, 3. If the birth of a preterm baby cannot be who have to do heavy manual labour, is prevented, it must be remembered that the decreased when they are pregnant and best incubator for transporting an infant that an opportunity to rest during working is the mother’s uterus. Even if the delivery hours is allowed. is inevitable, an attempt to suppress labour should be made, so that the patient can be5-14 How should you manage a patient transferred before the infant is born.at increased risk of preterm labour or 4. The better the condition of the infant onpreterm rupture of the membranes? arrival at the neonatal intensive care unit,1. Patients at increased risk must have two the better the prognosis. weekly vaginal examinations from 24 weeks, in order to make an early diagnosis of preterm cervical effacement and/or DIAGNOSIS OF dilatation.2. In all women with cervical effacement or PRETERM LABOUR AND dilatation before 34 weeks, the following PRETERM RUPTURE OF preventive measures can then be taken: • Bed rest. This can be at home, except THE MEMBRANES when the home circumstances are poor, in which case the patient should be 5-16 How should you distinguish admitted to hospital. between Braxton Hicks contractions and • Sick leave must be arranged for the contractions of preterm labour? working patients. • Coitus must be forbidden. Braxton Hicks contractions: • Patients must immediately report 1. Are irregular. if contractions or rupture of the 2. May cause discomfort but are not painful. membranes occur. 3. Do not increase in duration or frequency. • Women with preterm labour or preterm 4. Do not cause cervical effacement or rupture of the membranes must be seen dilatation. as soon as possible, and the correct measures taken to prevent the delivery The duration of contractions cannot be used of a severely preterm infant. as a distinguishing factor, as Braxton Hicks contractions may last up to 60 seconds. In contrast, the contractions of preterm or early labour:
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 1211. Are regular, at least one per ten minutes. 4. If no drainage of liquor is seen, a smear2. Are painful. should be taken from the posterior3. Increase in frequency and duration. vaginal fornix with a wooden spatula to4. Cause effacement and dilatation of the determine the pH and to test for ferning. cervix. 5. The possibility of cord prolapse can be excluded or confirmed.5-17 How should you confirm the 6. It is also important to see whether thediagnosis of preterm labour? cervix is long and closed, or whether there is already clear evidence of cervicalBoth of the following will be present in a effacement and/or dilatation.patient of less than 37 weeks gestation: 7. A patient with a profuse vaginal discharge1. Regular uterine contractions, palpable on or stress incontinence (leaking urine abdominal examination, of at least one when coughing or laughing) may think per ten minutes. that she is draining liquor. A speculum2. A history of rupture of the membranes, or examination will help to confirm or rule cervical effacement and/or dilatation, on out this possibility. vaginal examination. NOTE If the facilities are available, and preterm rupture of the membranes has been confirmed,5-18 How can you diagnose preterm an endocervical swab could be taken to culturerupture of the membranes? for Group B Streptococcus and Gonococcus.1. A patient of less than 37 weeks gestation will give a history of sudden drainage 5-20 How should you test the vaginal pH? of liquor followed by a continual leak 1. The pH of the vagina is acidic but the pH of smaller amounts, without associated of liquor is alkaline. uterine contractions. 2. Red litmus paper is pressed against the2. A sterile speculum examination will moist spatula. If the red litmus changes to confirm the diagnosis of ruptured blue, then liquor is present in the vagina, membranes. indicating that the membranes have3. A digital vaginal examination must not be ruptured. If blue litmus is used, it will done as it is of little value in diagnosing remain blue with rupture of membranes or rupture of the membranes and may change to red if the membranes are intact. increase the risk of infection. 5-21 How will you test for ferning? A digital vaginal examination must not be done 1. The vaginal fluid on the wooden spatula is if there is preterm rupture of the membranes. spread on a microscope slide and allowed to dry.5-19 What is the value of a sterile 2. The slide is then examined under thespeculum examination when preterm low power lens of a microscope. Anrupture of the membranes is suspected? unmistakable pattern of a fern leaf will be observed if the specimen is liquor.1. The danger of ascending infection is not increased by this procedure.2. Observing drainage of liquor from the cervical os confirms the diagnosis of ruptured membranes.3. If no drainage of liquor is observed, drainage can sometimes be seen if the patient is asked to cough.
    • 122 MATERNAL CAREMANAGEMENT OF 7. Antepartum haemorrhage of unknown cause.PRETERM LABOUR 8. Cervical dilatation of more than 6 cm. (However, contractions should be temporarily suppressed while the patient5-22 How will you manage a is being transferred to a hospital wherepatient in preterm labour? preterm infants can be managed.)Step 1 9. Severe intra-uterine growth restriction.Listen to the fetal heart to rule out fetal NOTE Antepartum haemorrhage of unknowndistress and determine the duration of cause may be due to a small abruptiopregnancy as accurately as possible: placentae. It is, therefore, advisable not to suppress labour should it occur.1. If fetal distress is present and the fetus is assessed to be viable (28 weeks or more), then the infant must be delivered as soon 5-24 How will you decide that a patient as possible. is less than 36 weeks pregnant if the2. If the pregnancy is 34 weeks or more, duration of the pregnancy is unknown? labour should be allowed to continue. This is done by measuring the symphysis-3. If the infant is assessed to be 24 weeks fundus height and by doing a complete or more but less than 34 weeks, other abdominal examination. contraindications for the suppression of preterm labour must be excluded. Labour must be suppressed if the estimated Subsequently the contractions should fetal weight is less than 2000 g or the estimated be suppressed with a calcium channel gestational age less than 34 weeks. The blocker, e.g. nifedipine (Adalat), or a beta2 symphysis-fundus height measurement will be stimulant, e.g. salbutamol (Ventolin). The less than 33 cm. further management of these patients must take place in a level 2 or 3 hospital. 5-25 How should you give nifedipine for4. The administration of steroids to enhance the suppression of preterm labour? fetal lung maturity prior to transfer should 1. Three nifedipine (Adalat) 10 mg capsules be discussed with the referral hospital. (total 30 mg) should be taken by mouth.Step 2 If there are no further contractions and no continuing cervical dilatation andLook for treatable causes of preterm labour, effacement, 20 mg should be given eight-such as urinary tract infection or malaria. hourly.The management of a patient with preterm 2. If there are still contractions with cervicallabour is summarised in flow diagram 5-1. dilatation and effacement three hours after the initial dose, a second dose of5-23 What are the contraindications to 20 mg should be given, followed by eight-the suppression of preterm labour? hourly doses.1. Fetal distress. Nifedipine (Adalat) has fewer side effects2. A pregnancy where the duration is 34 than salbutamol for the mother. Following weeks or more, or 24 weeks or less. the latest research, nifedipine (Adalat) has3. Chorioamnionitis. been recommended as the drug of choice in4. Intra-uterine death. suppressing uterine contractions.5. Congenital abnormalities incompatible with life.6. Pre-eclampsia.
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 123 Conservative Preterm management Labour No Yes 28 weeks or more? Fetal distress? Yes No 1.Intra-uterine No Yes Treat infection resuscitation Gestational age less Urinary tract and suppress 2.Deliver as soon as than 24 weeks? infection? labour possible No Yes Yes Cervical dilatation Give nifedipine Deliver 6 cm or less? No Yes Yes Neonatal care Duration of pregnancy Deliver available? less than 32 weeks? No Yes No Suppress labour Give Do not give and refer to a indomethacin indomethacin level 2 or 3 hospitalFlow diagram 5-1: The management of a patient with preterm labour when the duration of pregnancy is lessthan 34 weeks
    • 124 MATERNAL CARE5-26 What are the contraindications to the administration of the drug should be stoppeduse of nifedipine in suppressing labour? and preparation made for the delivery of a preterm infant.1. Nifedipine (Adalat) cannot be used for the suppression of preterm labour if patients have hypertension, or are suffering from any 5-28 What are the contraindications of the hypertensive disorders of pregnancy. to the use of beta2 stimulants2. Hypovolaemia or surgical shock due to any in suppressing labour? reason. 1. Heart valve disease. The use of beta23. Any condition that impairs the function of stimulants, such as salbutamol, can endanger the myocardium. the patient’s life, especially if she has a narrowed heart valve, e.g. mitral stenosis.5-27 How should you use salbutamol for 2. A shocked patient.the suppression of preterm labour? 3. A patient with tachycardia, e.g. as the result of an acute infection.1. Start an intravenous infusion of Ringer’s lactate and give 250 μg (0.5 ml) salbutamol slowly intravenously, after ensuring that 5-29 What additional action must there is no contraindication to its use. The you take to suppress labour? 0.5 ml salbutamol is diluted with 9.5 ml Prostaglandin antagonists, e.g. indomethacin sterile water and given slowly intravenously (Indocid), are prescribed. One indomethacin over five minutes while the maternal heart 100 mg rectal suppository is administered 12- rate is carefully monitored for tachycardia. hourly. Two doses are usually sufficient. The2. The initial dose is followed by a side- total dose should not exceed four doses (i.e. it infusion of 200 ml saline with 1000 μg shouldn’t be taken for more than 48 hours). salbutamol given at a rate of 30 ml per hour (150 μg per hour) until no further The following side effects make indomethacin contractions occur, or when the maternal potentially dangerous: pulse rate reaches 120 beats per minute. 1. Gastrointestinal irritation. If contractions persist, after two hours the 2. Suppression of platelet function. dose is doubled to 60 ml per hour (300 μg 3. Fluid retention. per hour) until no further contractions 4. Premature closure of the ductus arteriosus occur, or when the maternal pulse in the fetus. rate reaches 120 beats per minute.The 5. Renal failure in a patient with poor renal administration of the salbutamol infusion function. is continued until there are no further Indomethacin is also a useful drug to use if contractions, effacement, and/or dilatation there is a contraindication to giving a beta2 of the cervix for at least six hours. stimulant, e.g. maternal tachycardia due to3. The patient must be warned that salbutamol pyrexia. The risk of fetal death due to closure of causes tachycardia (palpitations). the ductus arteriosus by indomethacin is much4. Patients should be monitored with an greater after 31 weeks. Therefore, indomethacin ECG monitor while receiving intravenous should not be used from 32 weeks gestation. salbutamol. This should ideally occur within a high-care unit. Successful suppression of preterm labour with nifedipine (Adalat) or salbutamolIf the contractions are still occurring, and together with indomethacin is more likely ifthere is progressive effacement and dilatation antibiotics (ampicillin and metronidazole)of the cervix in spite of an adequate rate of are given in addition. Possible asymptomaticadministration, alternative measures must chorioamnionitis will then be treated as well.be taken to suppress labour. Otherwise,
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 1255-30 How should you manage the 3. The patient must continually be observedpatient further, after labour has for signs of fluid overload, the first sign ofbeen successfully suppressed? which is the presence of crepitations in the lungs as a result of pulmonary oedema.1. If there is a treatable cause, e.g. a urinary tract infection, then no further suppression of labour is necessary after the cause has 5-33 If the delivery of a preterm infant been treated. cannot be prevented, what action2. If nothing can be done about the cause should you take in order to make of the preterm labour, e.g. in the case of a the delivery as safe as possible? multiple pregnancy or polyhydramnios, 1. The mother must be transferred before nifedipine (Adalat) 20 mg may be given delivery to a hospital where preterm orally every six hours. infants can be managed. 2. Entonox (50% nitrous oxide and 50%5-31 What other action can be taken oxygen) or an epidural anaesthetic are theto improve the fetal outcome? preferred methods of providing analgesia. 3. The membranes should not be ruptured1. Steroids administered parenterally to the as they form a better cervical dilator mother cross the placenta and hasten the than the small fetal head. If they onset of fetal lung maturity. Betamethasone rupture spontaneously, a sterile vaginal (Celestone-Soluspan) 12 mg (2 ml) examination must be done to exclude an intramuscularly is the drug of choice. umbilical cord prolapse.2. Two doses of 12 mg each are given 4. A spontaneous vertex delivery, with 24 hours apart. Fetal lung maturity is an episiotomy if necessary, is the best usually, but not always, achieved 24 hours method of delivery. A well-controlled after the second dose. Suppression of delivery of the fetal head reduces the risk labour for 48 hours in order to give of intracranial haemorrhage. There is no betamethasone is, therefore, of value. evidence that the routine use of forceps has3. If the infant is not delivered and there is any advantage for the preterm infant. still a risk of preterm delivery, a single dose 5. Before the delivery, you must make sure of 12 mg can be given after a week. The that the equipment you need for the dose should not be repeated weekly until a resuscitation and management of the gestational age of 33 weeks is reached. preterm infant is available and in working NOTE : Fetuses that are exposed to repeated doses order. of steroids in pregnancy are born with a smaller head circumference and length. As the long-term neurological outcome is uncertain, the maximum MANAGEMENT OF dose described here should not be exceeded. PRETERM RUPTURE OF5-32 What are the dangers of using THE MEMBRANESsteroids to promote fetal lung maturity?1. Steroids must not be given if a clinically 5-34 How should you manage preterm detectable infection is the cause of the rupture of the membranes? preterm labour, because they may make the infection worse. There are two possible ways of managing2. Steroids cause fluid retention. Consequently, preterm rupture of the membranes: the amount of intravenous fluid which is 1. Labour can be induced. used to administer the salbutamol must be 2. The pregnancy can be allowed to continue. restricted.
    • 126 MATERNAL CAREThe management of a patient with preterm movements. Antenatal fetal heart raterupture of the membranes is summarised in monitoring is of great value.flow diagram 5-2. 2. Determine the duration of the pregnancy as accurately as possible. Remember, with5-35 How should you decide which preterm rupture of the membranes, bothmethod of management to use? clinical and ultrasound examinations tend to underestimate the duration of pregnancy.The danger of prematurity if the fetus is 3. Look for signs of clinical chorioamnionitis.delivered must be weighed against the risk ofinfection in both the mother and the fetus if If the history and clinical examination indicatethe pregnancy is allowed to continue. a pregnancy of less than 34 weeks duration, an ultrasound examination is of value in5-36 What is the reason for allowing determining fetal size and possible grossthe pregnancy to continue with congenital abnormalities.preterm rupture of the membranes? 5-39 What are the indications forTo provide time for the fetal lungs to mature induction of labour when preterm ruptureand, thereby, to reduce the danger of hyaline of the membranes has occurred?membrane disease after delivery. 1. An HIV-positive patient. 2. A duration of pregnancy of 34 weeks or Prematurity remains the commonest cause of more. neonatal death resulting from preterm rupture 3. A duration of pregnancy less than 26 weeks. of the membranes. 4. Intra-uterine death or severe fetal congenital abnormalities.5-37 Which patients with preterm 5. Signs of clinical chorioamnionitis.rupture of the membranes are at an 6. Maternal illness such as pre-eclampsia orincreased risk of chorioamnionitis? diabetes mellitus. 7. Severe intra-uterine growth restriction.Patients with preterm rupture of the 8. Antepartum haemorrhage of unknownmembranes plus one or more of the following cause.factors are at a particularly high risk ofchorioamnionitis: 5-40 What method of induction1. HIV-positive patients with immune should you use? suppression, either: The method of choice is to stimulate uterine • A CD4 count of less than 350 cells/mm3. contractions with oxytocin. If there are • An AIDS-defining infection that contraindications to stimulating labour or to indicates clinical immune suppression. a vaginal delivery, then a Caesarean section2. Rupture of the membranes during or is done. following coitus.3. A digital vaginal examination following 5-41 What should the daily care of a patient rupture of the membranes. include if pregnancy is allowed to continue?4. No antenatal care. 1. The patient must be kept on bed rest, being5-38 What should you do once preterm allowed up to the toilet. She must not sit inrupture of the membranes has occurred? a bath, but should use a shower. 2. Digital vaginal examinations must not be1. Check whether the fetus is still alive, and done. exclude fetal distress by assessing fetal 3. The condition of the fetus must be monitored daily, preferably with a
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 127 Conservative Prelabour rupture management of membranes No Yes No Sterile 28 weeks or more? Fetal speculum distress? examination Yes 1.Intra-uterine No resuscitation Discharge Liquor in 2.Deliver as soon as vagina? possible Yes Yes Prolapsed cord? No Yes Duration of pregnancy less Oxytocin to than 26 weeks, or 34 or induce labour more weeks? No No Yes Signs of clinical Conservative chorioamnionitis? managementFlow diagram 5-2: The management of a patient with preterm prelabour rupture of the membranes
    • 128 MATERNAL CARE cardiotocograph. If this is not available, fetal develop contractions before 24 hours have movements must be counted and recorded. passed after giving steroids, and there are no4. Observations for signs of clinical clinical signs of chorioamnionitis or any other chorioamnionitis must be done: contraindications to the suppression of preterm labour, the labour must be suppressed with • The maternal pulse rate and nifedipine (Adalat) or salbutamol (Ventolin). temperature and the fetal heart rate An attempt is thus made to expose the fetal must be checked four-hourly. lungs to steroids for at least 24 hours. • An abdominal examination is done twice a day to check for uterine 5-43 Which physical signs will be tenderness. present if a patient develops severe • At the same time it is noted whether or infection (septic shock) and what not the liquor is offensive. will the initial management be? 1. The signs of clinical chorioamnionitis The first digital vaginal examination in a patient already mentioned will be present. In with preterm rupture of the membranes is done addition, there will be a drop in the blood only when she is in established labour. pressure and cold clammy extremities, if severe infection (septic shock) develops.5-42 How long should you allow 2. The patient must be actively resuscitatedthe pregnancy to continue? and treated with ampicillin, metronidazole (Flagyl) and gentamicin. The patient must1. If complications, such as chorioamnionitis then be referred to a level 2 or 3 hospital. and fetal distress, do not develop, the pregnancy is allowed to continue until 5-44 What advice should you the patient goes into labour. However, if give to a woman who has the pregnancy reaches 34 weeks duration delivered a preterm infant? and the patient is still draining liquor, an oxytocin induction is done. 1. She should be seen before her next2. A patient who has stopped draining liquor pregnancy to be assessed for possible completely and where liquor is present causes, e.g. cervical incompetence. on abdominal examination, with no signs 2. She must book early in any future of chorioamnionitis, may be allowed pregnancy. to continue her pregnancy until the spontaneous onset of labour. The patient may be allowed home if no liquor has PRELABOUR RUPTURE drained for two days. However, she is not allowed to sit in a bath or to have coitus. OF THE MEMBRANES The patient must be followed up weekly at a high-risk clinic. 5-45 How should you manage a patient NOTE The administration of steroids will promote with prelabour rupture of the membranes? fetal lung maturity if patients with preterm 1. If a patient has prelabour ruptured rupture of the membranes are managed membranes and there are signs of conservatively. Betamethasone (Celestone chorioamnionitis, then labour should be Soluspan) 12 mg (2 ml) is given intramuscularly. induced without delay. The dose is repeated after 24 hours. Because steroids may increase the risk of infection, 2. HIV-positive patients should be started on ampicillin and metronidazole (Flagyl) must a course of antibiotics and labour should also be prescribed, as in the case where be induced: preterm labour is being suppressed. If a patient who is being managed in this way should
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 129 • The longer the interval between rupture 3. Why could chorioamnionitis still be of the membranes and delivery, the the cause of her preterm labour? greater the risk of mother-to-child Because chorioamnionitis is often transmission of HIV. asymptomatic. • The patient has a higher risk of chorioamnionitis.3. However, if the patient is at low risk of 4. Would you allow labour to continue chorioamnionitis and both fetal and or would you suppress labour? maternal conditions are good, you can Labour should be suppressed because the wait for 24 hours after the membranes pregnancy is of less than 34 weeks duration, have ruptured before inducing labour. the fetus is viable, and there are no signs of About 80% of patients will go into labour clinical chorioamnionitis or fetal distress. spontaneously within this period. A digital vaginal examination should not be done 5. How should labour be suppressed? until the patient is in labour. Labour must be suppressed using nifedipine NOTE In busy hospitals with a high bed (Adalat) or salbutamol (Ventolin). occupancy rate, patients with prelabour rupture of the membranes can have their labour induced 6. Which other drugs would with oxytocin after the diagnosis is confirmed. increase the chance of successful Induction of labour in these circumstances does not result in a higher Caesarean section suppression of preterm labour? rate but reduces hospital stay by 24 hours. Antibiotics, such as ampicillin and metronidazole (Flagyl), increase the likelihood of successful suppression of preterm labourCASE STUDY 1 if the labour is caused by asymptomatic chorioamnionitis.A patient, 32 weeks pregnant, presents withregular painful uterine contractions. She 7. Must indomethicin (Indocid) alsois apyrexial and appears clinically well. On be given?vaginal examination, the cervix is 4 cm dilated. No, as the patient is already 32 weeksThe fetal heart rate is 138 beats per minute pregnant. The risk of closing the ductuswith no decelerations. arteriosus and causing intra-uterine deaths increases from 32 weeks.1. Is the patient in true or false labour?Give the reasons for your diagnosis. 8. Which drugs can be used to hastenShe is in true labour because she is getting fetal lung maturity, and would you giveregular painful contractions and her cervix is one of these drugs to this patient?4 cm dilated. Steroids, such as betamethasone, can be given to the patient to hasten lung maturity in the2. What signs exclude a diagnosis fetus. As this patient’s pregnancy is less thanof clinical chorioamnionitis? 34 weeks and there are no signs of clinicalThe patient is apyrexial, clinically well and has chorioamnionitis, steroids must be given.a normal fetal heart rate.
    • 130 MATERNAL CARECASE STUDY 2 of rupture can be allowed before inducing labour. Most patients will go into labour spontaneously during this period.A patient, who is 36 weeks pregnant, reportsthat she has been draining liquor since earlierthat day. The patient appears well, with normal 6. Should you prescribe antibiotics?observations, no uterine contractions and the Give your reasons.fetal heart rate is normal. There is no indication for giving antibiotics as there are no signs of clinical1. Would you diagnose rupture chorioamnionitis. However, a careful watchof the membranes on the history must be kept for early signs of maternalgiven by the patient? infection or fetal tachycardia.No, other causes of fluid draining from thevagina may cause confusion, e.g. a vaginitis orstress incontinence. CASE STUDY 32. How would you confirm An unbooked patient presents with a five-rupture of the membranes? day history of ruptured membranes. She is pyrexial with lower abdominal tenderness andA sterile speculum examination should be is draining offensive liquor. She is uncertain ofdone. If there is no clear evidence of liquor her dates but abdominal examination suggestsdraining, the vaginal pH using litmus paper that she is at term. Treatment has been startedand microscopy for ferning can be used to with oral ampicillin.identify liquor. 1. What signs of clinical chorioamnionitis3. Why should you not perform a digital does the patient have?vaginal examination to assess whetherthe cervix is dilated or effaced? She is pyrexial, with lower abdominal tenderness and she has offensive liquor.A digital vaginal examination is contraindicatedin the presence of rupture of the membranes if 2. Would you induce labour in thisthe patient is not already in labour, because of patient? Give your reasons.the risk of introducing infection. Yes, because there is danger of spreading4. Is this patient at high risk of having infection in both the mother and fetus if theor developing chorioamnionitis? infant is not delivered. The patient is in grave danger of developing septic shock. LabourYes. The preterm prelabour rupture of should be induced with oxytocin, if therethe membranes may have been caused by is no indication for an immediate delivery,chorioamnionitis. In addition, all patients with e.g. fetal distress. With signs of septic shock,ruptured membranes are at an increased risk the patient must be actively resuscitated andof developing chorioamnionitis. treated with broad-spectrum antibiotics, followed by delivery of the fetus. The earliest5. Should you induce labour? sign of septic shock will be a fall in the bloodGive your reasons. pressure, followed by the patient developing cold, clammy extremities.Yes. As she is more than 34 weeks pregnant,one should induce labour. As the patient doesnot fall into a high-risk group for infection,a waiting period of 24 hours from the time
    • PRETERM LABOUR AND PRETERM RUPTURE OF THE MEMBRANES 1313. Should you continue to treat the patient 4. Why is the infant at increased riskwith oral ampicillin? Give your reasons. for neonatal complications?She should be treated with appropriate broad- The chorioamnionitis has already spread to thespectrum antibiotics, given in adequate liquor as this is offensive. Therefore, the fetusdosages until her pyrexia has subsided. As it may also be infected and may present withis not clear how long the infection has been congenital pneumonia or septicaemia at birth.present, gentamicin must be added to theampicillin and metronidazole (Flagyl) untilthe patient has been apyrexial for 24 hours.The gentamicin and ampicillin must initiallybe given intravenously and the metronidazoleas a rectal suppository.