This document discusses the mechanism of labour and use of the partogram. It defines labour as painful, regular uterine contractions that progressively efface and dilate the cervix, causing descent and rotation of the fetal head. The three stages of labour are also described: 1) cervical dilation from 0-10cm, 2) baby being born, 3) delivery of placenta. Key components that aid delivery are contractions of the uterus, the bony pelvis and soft tissues as passages, and the fetus. Progress of labour is tracked using a partogram to monitor cervical dilation and identify any issues requiring action.

1. Mechanism of labour and use
of partogram
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2. Definition of labour
 Painful, regular uterine contractions.
 Progressive effacement(shortening) and dilatation of
cervix.
 Causing descent and rotation of fetal head
 Full dilatation contractions become expulsive leading to
delivery of baby.
 Delivery of placenta and membranes follows.

3. COMPONENTS OF LABOUR
 The powers
 Uterine contractions
 The passages
 bony pelvis, and soft tissues
 The passenger
 fetus

4. Onset of labour
 Stimuli - maternal (stretch, hormones) & fetal (?
adrenal)
 Painful contractions.
 Show.
 Rupture of membranes.
 Shortening and dilatation of cervix.

5. First stage of labour
 Latent phase
effacement
dilation 0-3cm.
 Active phase
dilation 3-10cm.

6. Stages of labour
 Second stage - from full dilatation until baby born.
 Third stage - From birth of baby until placenta and
membranes delivered.

7. The powers- contractions
 Painful.
 Increase in
frequency to 1:2-3
 Increase in strength.
 Cervix pulled up
 Head passes down
like toe through
hole in sock

8. Diagnosis
 tocograph measures frequency and duration of
contractions not intensity and tone
 intensity - gauge by amount of pain
 analgesia use, change in pain
 strength - gauge by abdominal palpation
 midwife, yourself

9. Passages- the pelvis
 Bony pelvis
 Brim - ovoid
 Cavity - circle
 Outlet - ovoid
 Pelvic floor
 slopes directing
presenting part
forward under pubic
arch

10. Passenger - the baby

11. Flexion
 Encouraged by
downward pressure
from contractions.
 Brings smallest
diameter into
engagement
 Posterior fontanelle
lower than anterior

12. Internal rotation and extension
 Second stage -
descent
 Presenting part
reaches sloping pelvic
floor.
 Causes lowest point
(occiput) to rotate
forward
 Further descent ,
head extends.

13. Crowning
 Extending head
stretches perineum
gradually.
 Greatest diameter
passes through
vulva.Further
extension allows
forehead face and
chin to escape.

14. Restitution and external rotation
 After internal
rotation head twisted
on shoulders. Delivers
facing down.
 Anterior shoulder
rotates on hitting
pelvic floor into
wider AP diameter of
pelvis.
 Neck untwists,
causing head to turn
sideways.

15. Delivery of body
 Top shoulder escapes from under pubic arch
 Bottom one slides over perineum
 Oxytocic given to mother to help with 3rd stage
 Rest of body follows.
 Cord clamped and divided.

16. Third stage
 Contractions cause
separation of
placenta.
 Pushed down into
lower segment
 Signs - lengthening of
cord,uterus rises up,
small gush of blood,
placenta felt in
vagina

17. Active management of 3rd stage
 This reduces blood
loss
 Oxytocic given after
delivery of anterior
shoulder.
 Hand placed
suprapubically
pushes up gently
 Cord traction.

18. Haemostasis
 Uterus contracts
after delivery
 This compresses
vessels.
 Reducing blood loss

19. Management of labour
 Fetal & maternal observations.
 Encourage to mobilise
 Pain relief - TENS, Entonox, Opiates, Epidural.
 Antacids, Ranitidine- reduce acidity and risk of
aspiration.

20. Partogram
 Used in established
labour to check progress
 Plots cervical dilatation.
 Alert and action lines
 Maternal T, P, BP, urine,
contractions.
 Fetal heart rate,
descent, moulding &
caput.
 Liquor
 Fluids & drugs.

21. Fetal observations
 Admission CTG to
check well being
 Intermittent
monitoring by
listening in after
contractions