Oxford Handbook of Midwifery (82 page)

• Monitoring is not indicated if the gestational age is assessed to be
  

  <25 weeks
  

• If the gestational age is estimated to be 27 weeks, discuss with the consultant obstetrician the action to take if the pattern is abnormal (b see Cardiotocograph monitoring, p. 236).
  
• At <34 weeks the fetal heart is less likely to demonstrate sleep/ wake patterns; accelerations to 10 beats are considered normal in this context
  

Careful monitoring and assessment by the midwife will assist an accurate diagnosis.

Further assessment will be made by the obstetrician.

• Ensure privacy for the woman, obtain consent, and explain the procedure.
  
• Ask the woman to rest on the bed for 30min and to wear a sanitary pad. This is to allow the collection of any fluid, ‘pooling of liquor’ in the vagina prior to the assessment.
  

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• Exclude vaginal bleeding/PPROM/discharge.
  
• Exclude infection and take swabs for culture and antibiotic sensitivity: a high vaginal swab and endocervical swab for
  Chlamydia
  , a rectal and introital swab for GBS. If infection is suspected, send blood cultures urgently to bacteriology.
  
• An ultrasound scan may be necessary, e.g. to assess fetal size,
  presentation, breathing movements, or liquor volume. (The early
  

  pregnancy ultrasound scan will be most accurate when establishing
  

  gestation.)
  

• An IV line should be sited. Take blood samples for FBC and U/E; G&S if labour seems to be establishing or there is any bleeding. If the cervix is <2cm in a primigravida or <3cm in a multigravida, commence 500mL normal saline over 4h and give oral analgesia.
  
• If the woman’s blood group is Rh-negative, take blood for Kleihauer’s test. This test detects whether any (potentially Rh-positive) fetal cells have crossed over into the maternal circulation. This may happen, for example, as a result of injury or placental bleeding. In cases of threatened preterm labour this cannot be excluded. Anti-D 500IU (which coats and eliminates any Rh-positive fetal cells in the mother‘s blood and so prevents maternal sensitivity) may be prescribed.
  

  Threatened preterm labour <34 weeks (without PPROM)
  

• The plan of management aims to delay the delivery of a preterm baby for 24–48h, to allow for the administration of intramuscular steroid therapy to the mother or to facilitate intrauterine transfer (see below). Tocolytics, drugs which may delay established labour and delivery,
  

  are not usually given if the woman has already received the required steroid therapy.
  

• The plan to treat a woman who appears to be experiencing threatened preterm labour may be based on the use of the fetal fibronectin
  

  test (fFt). The fFt may facilitate diagnosis of women at minimal risk of progressing in preterm labour. This is a negative fFt and can prevent unnecessary treatment.
  

  • The test involves taking a swab of cervicovaginal secretions from the posterior fornix and ectocervix during a speculum examination.
    
  • Fetal fibronectin is a glycoprotein found in the secretions. When present at levels which are detectable on the test between 24–34 weeks of pregnancy it is associated with preterm delivery.
    
  • fFt negative: 0.8% risk of delivery in 7–10days. If symptoms persist repeat test in 24h. Seek senior obstetric advice before transferring the woman or discharge home.
    
  • fFt positive: 14% risk of delivery in 7–10 days. Administer tocolytics and steroids and ensure neonatal provision.
    ¹
    
• Indications: 24–34 weeks’ gestation with intact membranes and symptoms of preterm labour with the intention to treat with tocolytics and steroids.
  
• Contraindications: multiple pregnancy, coitus in previous 24h, moderate bleeding PV or ruptured membranes,
  

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• Give two doses of betamethasone 12mg IM 12 or 24h apart.
  
• After the initial course the baby will benefit after approximately 24h
  

  and for up to 7 days.
  

• However, repeated doses to a woman who remains undelivered but still at risk may be less beneficial, because corticosteroid administration may be associated with endocrine defects in infants.
  
• Systemic infection in the mother is a contraindication to administration.
  

• Betamimetics: ritodrine, salbutamol, terbutaline
  
• Prostaglandin synthetase inhibitors: indometacin
  
• However, since these may have serious side-effects and much careful monitoring of the mother and fetus is required. The oxytocin antagonist atosiban is preferable.
  

• Fetal heart pattern irregularities
  
• Placental abruption or active bleeding
  
• Infection/chorioamnionitis
  
• PPROM
  
• Severe pre-eclampsia, since delivery is necessary.
  

• Atosiban may be used when a diagnosis of uncomplicated preterm labour has been made between 24 and 33 (+6 days) weeks’ gestation.
  
• It may also be used if a woman with a history of spontaneous preterm delivery at less than 34 weeks’ gestation presents with uterine contractions without cervical changes.
  
• Measure the woman’s blood pressure and pulse to provide a baseline. Hourly observations are then adequate.
  
• Continuous monitoring is indicated throughout the treatment period, especially if there is any bleeding or concern for fetal well-being. If contractions stop and there are no other concerns, intermittent auscultation for 2min every hour may be performed until treatment is complete.
  
• Atosiban is not associated with serious side-effects and is well tolerated. It is quickly cleared from the body after the infusion is discontinued. Nausea, vomiting, headache, fever, tachycardia,
  

  hyperglycaemia, hypotension, and injection site reaction have been reported.
  

• Treatment can be repeated if regular uterine contractions recur.
  

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  PPROM <34 weeks’ gestation
  

  Following diagnosis, provided it is safe to do so, the woman should be transferred to a hospital with neonatal intensive care facilities. She should be treated conservatively, with admission to an antenatal ward for obser- vation.
  

  The midwife should:
  

  •
  Observe the woman’s temperature and pulse 4h
  

  • Give medications as prescribed: steroid therapy and broad-spectrum
    

    antibiotics (erythromycin 500mg four times daily for 10 days) if required
    

  • Assess the woman’s discomfort and be vigilant for any onset of uterine contractions
    
  • Assess the amount, colour, and smell of PV loss
    
  • Perform CTG as requested by the obstetrician
    
  • Take blood for a FBC (for white cell count) and C-reactive protein estimation (CRP levels increase to >10mg/L during acute
    

    inflammation). These blood samples, taken on alternate days, will help to assess for infection
    

  • Arrange ultrasound scanning as requested by the obstetrician, to measure remaining amniotic fluid and assess the growth of the fetus
    
  • Report promptly any changes in maternal/fetal condition to the obstetrician.
    

    Delivery is indicated if
    

  • There is evidence of infection:
    
    • Chorioamnionitis
      , indicated by:
      
      • A rising maternal temperature and pulse
        
      • A tachycardic fetal heart
        
      • Maternal abdominal pain, especially on palpation of the uterus
        
      • An offensive discharge PV
        
      • The maternal white cell count and CRP may be raised.
        
    • B-Haemolytic streptococci
      
      • If there is definite infection recorded from microscopy on the vaginal swab, the woman should be delivered with IV antibiotic cover.
        
  • Labour occurs spontaneously. It should be allowed to progress without the use of tocolytic drugs.
    
  • The fetus is mature enough at approximately 34 weeks’ gestation.
    
  • The decision to deliver has been made by a consultant/senior obstetrician.
    
  • The paediatrician and NICU have been informed of the full case history.
    

    PPROM >34 weeks’ gestation
    

  • PPROM is frequently associated with infection, and the risks associated with infection are higher than the risks of prematurity. Therefore, following a definite diagnosis and if the woman is not in labour, induction may be indicated.
    

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