The document provides an overview of normal labor, detailing its definition, components, stages, and mechanics. It discusses the importance of uterine contractions, fetal positioning, and anatomical measurements during labor. Additionally, it covers placental separation and the management of labor to reduce postpartum hemorrhage.

1. Normal labour
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2. NORMAL LABOUR
 Labour is defined as the onset of
painful, regular uterine contractions
with progressive cervical dilatation
accompanied by descent of
presenting part.
 Physiological process during which
the products of conceptus are
expelled from the uterus
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3. COMPONENTS OF NORMAL
LABOUR
Powers
Passage
Passenger
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4. passage-the female pelvis
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5. Pelvic inlet 13cm 11cm
Mid cavity 12cm 12cm
Pelvic outlet 11cm 13cm
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transverse Anterior- Posterior
diameter

6. DIAMETERS OF THE PELVIC
INLET
ANTEROPOSTERIOR DIAMETERS
 Anatomical conjugate 11cm
- From the tip of sacral promontary to
upper border of S.P.
 Obstetric conjugate 10,5 cm
- From the tip of promontary to the most
bulging point of the back S.P.
 Diagonal conjugate 12,5 cm
- From the tip of promontary to lower
border of S.P.
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7. Diameters of the pelvic inlet
 Transverse diameter
- Between the widest points of the
pelvic brim 13 cm.
 Oblique diameters 12cm
-From sacroiliac joint of one side to
the iliopectinal eminence of the
opposite side
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8. III PELVIC OUTLET
Diameters of pelvic outlet.
-Anteroposterior diameters
-Anatomical 11cm
-Obstetric 13 cm
-Transverse diameters
Between ischial tuberosities 11 cm
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9. THE PASSENGER
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10. THE FETAL SKULL
 Sutures:
Saggital suture ----- separates parietal bones
Frontal suture------- separates frontal bones.
Coronal suture------ separates frontal &
parietal bones.
Lambdoid suture--- separates parietal &
occipital bones
 Fontanelles
- Anterior fontanelle( Bregma) : Meeting of
frontal,coronal& saggital sutures
- Posterior fontanelle: Meeting of saggital &
lambdoid sutures
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11. 1. Moulding
 It is over riding of the bones of the
vault over each other to allow some
reduction of the diameters.
 First degree : Approximation of skull
bones
 Second degree : Overriding of bones
but reducible
 Third degree: Irreducible overriding
of skull bones, sign of obstructed
labour and may lead to intracranial
hemorrhage
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12. DIAMETERS OF THE FETAL
SKULL
 SUBOCCIPITO-Bregmatic 9.5 cm
- From posterior junction of head& neck to
center of anterior fontanelle.
Frontal 10cm From posterior junction of
head, neck to anterior end of bregma-
Occipital-frontal 11,5 cm
- From occiput to root of the nose-
- Mento vertical 13,5 cm tip of chin to
furthest point on sagittal suture
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13. The power
The uterine contractions
 True uterine contractions are
characterized by being:
- Involuntary Intermittent ,Increase in
frequency & duration as labour
advances.
- Associated with Fore water bulging
Effective contractions are : 3-5/10min
in frequency
- 40-60 sec in duration
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14. Stages of labour
 First stage
Onset from true labour pain
End :full cervical dilatation
Duration : Prim gravida 12-16hrs
Multigravida 6-8 hrs.
 Second stage
Onset : Full cervical dilatation
End : Delivery of the fetus
Duration : Prim gravida 1hour
Multigravida 30 min
 Third stage
Onset : delivery of the fetus
End: delivery of placenta
Duration: < 30 min. 14

15. Diagnosis of the onset of labour
 Symptoms: True labour pain (backache)
Passage of show : passage of cervical
mucous plug as the cervix dilates
 Signs: Dilatation& Effacement of the
cervix
Formation of bag of fore water
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16. Mechanism of normal labour
 First stage of labour
- Uterine contractions
- Cervical dilatation: It is due to uterine
contractions & retractions. Fetal pressure and
also pressure of the bag of fore water
- Cervical effacement : It is progressive taking
up of the cervix and its incorporation into lower
uterine segment It is detected clinically by the
progressive thinning of the cervix.
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17. 17
FMJ- Fibromascular junction

18. Cervical effacement
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19. Second stage of labour
 Diagnosis of onset of the second
stage of labour:
Symptoms: Involuntary bearing
down, desire of defecate
Signs: Perineal bulge.
Full cervical dilatation 10 cm
delivery of the baby
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20. Mechanism of labour
 Descent -It is constant movement
throughout delivery
 Engagement- Passage of the widest
diameters of Presenting Part below
pelvic inlet
Diagnosis of engagement: 2/5 head
palpable abdominally
Vaginally- Head station at zero.
.
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21. Mechanism of labour
 flexion- is due to resistance from the
bony pelvis and the pelvic floor soft
tissues as the head descends
 Internal rotation
- Aim to bring the longest diameter of
Presenting Part to the longest diameter of
the pelvic outlet
The occiput meets the pelvic floor then
rotates to lie behind S.P.
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22. Mechanism of labour
 Extension
It is movement of which the fetal
head is expelled outside of vulva.
Mechanism: The suboccipital region
hings under S.P. then head extends
to be delivered.
 Restitution
Occiput rotates 1/8 of a circle in
direction opposite to that of internal
rotation 22

23.  External rotation
It is rotation of the head after its delivery
Secondary to internal rotation of shoulders
 Delivery of shoulders:
The biacromial diameter enters the
opposite obligue diameter to that of the
head.Then anterior shoulder meets the
pelvic floor first rotates 1/8 of circle,with
further descent its hinges below SP
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24. Placental separation
SCHULTZ 80% DUNCAN
20%
Separation Centrally Lower pole
Presents By fetal surface By lower pole
Bleeding Less More
Retained parts Less risk More risk
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25. Maternal surface of placenta
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26. Third stage of labour
 Placenta descent to lower uterine
segment
Signs of placental separation:
1. Gush of dark blood
2. Apparent cord elongation
3. Suprapubic bulge
4. Fundus rises,becomes firm
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27. Active management of labour
(AMTSL)
 IM oxytocin 10IU with one minute of delivery of
baby
 Support suprapubic area with one hand
 Controlled cord traction
 Massage of uterus
 Inspection for tears
• Reduces PPH by 60%
 Caution of ergometrin in
• Cardiac disease, hypertension
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28.  Fetal surface of placenta
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29. End
Any questions?
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