Oxford Handbook of Midwifery (81 page)

caesarean section, as the shedding of virus during labour is high.

length of time that the membranes have been ruptured. If vaginal birth is unavoidable, or it is more than 4hr since the rupture of membranes, give the mother and baby aciclovir.
⁴

1. Read JS (2000). Preventing mother to child transmission of HIV: the role of caesarean section.
   

   Sexually Transmitted Infections
   76
   , 231–2.
   

2. Sheffield Teaching Hospitals NHS Trust (2009).
   Jessop Wing Labour Ward Guidelines 2009–2010
   . Sheffield: Sheffield Teaching Hospitals NHS Trust.
   
3. Low-Beer NM, Smith JR (2002).
   Management of genital herpes in pregnancy
   . Green Top Guideline 30. London: RCOG Press.
   
4. MacLean A, Regan L, Carrington D (2001).
   RCOG 40th Study Group ‘Infection and Pregnancy’
   . London: RCOG Press.
   

   CHAPTER 18
   High-risk labour
   

   352‌‌
   

   Group B haemolytic streptococcus
   

   Women who are at risk of giving birth to a baby with GBS infection should be offered antibiotics in labour. If the woman accepts, the treatment must be administered at least 4h before the birth in order to have maximum effect. Timely intrapartum treatment with antibiotics reduces the inci-
   

   dence of GBS infection in the neonate occurring in the first 7 days after birth. There are a number of other circumstances to consider:
   ¹
   

   • If a woman is admitted with prelabour rupture of the membranes after 36 weeks’ gestation and is known to carry GBS, she should not be treated conservatively but advised induction of labour and intrapartum antibiotic prophylaxis.
     
   • If a woman is known to have GBS vaginal colonization and gives birth by elective caesarean section with intact membranes, there is no evidence that antibiotic prophylaxis is beneficial.
     
   • A woman admitted in preterm labour should have introital, rectal, and high vaginal swabs on admission. If any show positive for GBS and the result is available before labour is advanced then intrapartum antibiotics should be offered.
     
   • Prolonged rupture of membranes after 37 weeks. Antibiotics are not indicated unless GBS has been detected antenatally, or the woman has had a baby with neonatal GBS, or she becomes pyrexial in labour. She should have a rectal and introital swab to screen for GBS.
     
   • GBS vaginal colonization and home delivery. The same GBS prevention strategy should be offered to all women regardless of place of birth. Risks and benefits of home birth in these circumstances should be discussed and an agreed plan of action documented.
     
   • A woman known to have GBS colonization should be offered rectal and introital swabs at 37 weeks’ gestation. If the swabs are negative the risk of being colonized before the birth is low. If the swabs are positive she could be offered a course of oral antibiotics and a follow-up swab taken after treatment. If this is negative the risk is low.
     
   • The woman should be aware that if she goes into labour before the follow-up swab result is available, the oral antibiotics may not have cleared the infection. In either case the woman may be willing to accept these risks and give birth at home.
     
   • Attending labour ward for a dose of antibiotics and then returning home for the birth. This option would only be practical in isolated cases where the woman lives close by and has safe, reliable transport. The drawbacks of this are that she may give birth while travelling to and from hospital and if the labour is long she will require a second dose
     

     of antibiotics. A recommended regimen is benzylpenicillin 3g (5 mega units) IV stat followed by 1.5g (2.5 mega units) at 4h intervals until delivery. When a woman has a penicillin allergy, give clindamycin 900mg IV every 8h until delivery. Follow local preferences for treatment.
     

     1
     Royal College of Obstetricians and Gynaecologists (2003).
     Guideline No. 36 Prevention of Early Onset Neonatal Group B Streptococcal Disease
     . London: RCOG Press.
     

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     CHAPTER 18
     High-risk labour
     

     354‌‌
     

     Preterm labour
     

     Definitions
     

   • Threatened preterm labour
     : pregnancy complicated by clinically significant uterine activity but without cervical change.
     
   • Preterm labour
     : the occurrence of regular uterine contractions which
     cause cervical effacement or dilatation prior to 37 completed weeks of
     

     pregnancy.
     

     Preterm, prelabour rupture of the membranes
     

     This occurs in more than one-third of preterm labours. Most women so affected will deliver within 1 week. Prelabour rupture of the membranes (PPROM) is often associated with maternal infection.
     

     Incidence of preterm delivery
     

   • Just under 7% of UK births are preterm.
     
   • Less than one-quarter of UK preterm births are <32 weeks’ gestation.
     

     Some predisposing factors
     

   • Pre-eclampsia, eclampsia
     
   • APH, placental abruption, placenta praevia
     
   • Intrauterine growth retardation
     
   • Disease or infection in the woman or fetus
     
   • PPROM
     
   • Intrauterine death
     
   • Multiple pregnancy
     
   • Polyhydramnios
     
   • Congenital abnormalities
     
   • Previous preterm labour (in selected cases cervical suture may have been placed to reduce the risk of a second preterm delivery)
     
   • Cervical incompetence (may be a result of cervical surgery or surgical termination of pregnancy).
     

     Risks of preterm delivery
     

   • Major problems occur for babies born after 24 weeks’ (when the baby is viable) and before 33 weeks’ gestation.
     
   • Fetal death may occur as a result of intraventricular haemorrhage, RDS, infection, jaundice, hypoglycaemia, or necrotizing endocolitis.
     
   • In cases of PPROM, survival rates are linked to the gestation at membrane rupture rather than duration of rupture. There is a high risk of chorioamnionitis.
     
   • The prognosis depends on the antenatal administration of steroids to the mother, the gestation, and birthweight, condition at birth, and the immediate care after birth, including the availability of a neonatal intensive care unit (NICU).
     

PRETERM LABOUR

355

Diagnosis and management of preterm labour

A woman may present to the delivery suite with regular painful contrac- tions before 37 weeks’ gestation.

The midwife should:

current pregnancy. Note her Rh status and blood grouping