13.06.01 Normal labour

Definition

    • Products of conception expelled by the mother

    • Progressive dilatation and effacement of the cervix

    • Painful, regular contractions

Stages of labour

    • Stages

      • First = Onset of true uterine contractions to full dilatation of cervix

      • Second = Full dilatation and rupture of membrane to delivery of foetus

      • Third = Complete expulsion of foetus to complete expulsion of placenta and membranes

    • Latent/active

      • Latent = <4 cm dilated, irregular contractions

      • Active = >4 cm dilated, rapid further dilatation, fast/continuous contractions

Assessment of cervix

    • Dilatation

    • Effacement

    • Consistency

    • Position of foetus

    • Presenting part

Post-partum haemorrhage

    • Primary (<24 hrs)

      • Atonic uterus

      • Retained placental part

      • Tears

    • Secondary (>24 hrs - 6 weeks)

      • RPOC

      • Infection

      • Endometritis

Bishop score

  • Interpretation

    • > 8 => Likely to achieve a successful vaginal birth

    • < 7 => Cervical ripening method (prostaglandins)

Indications for induction

    • Post-term

    • Pre-eclampsia

    • Obstructive cholestasis (risk of stillbirth)

    • Diabetes (big baby)

Head position

    • OA = Best

    • ROA/LOA = Fine, but a bit slower as it has to rotate

    • Transverse get stuck

    • OP get stuck (face presentation)

CTG interpretation

Fetal blood sampling

    • pH < 7.2 => Urgent delivery

    • pH 7.2 - 7.25 => Repeat in 30 mins

    • pH 7.25 - 7.3 => Repeat in 60 mins

Notes

    • Braxton-Hicks contractions: Irregular, occur throughout pregnancy, start at first trimester

    • Power, Passage, Passenger

    • Uterine muscle doesn't ever relax - just progressively contracts

    • Oxytoxin to encourage the placenta out (if >30 mins)

  • ERCP = Evacuation of retained products of conception

  • Station is measured relative to ischial spines (zero = head at spines)

  • STAN = ST analysis/T:QRS ratio = Measure of chronic oxygen deprivation