Normal Labour

1. Labour
Pavemedicine.com

2. objectives
 Define labour.
 Understand the components of labour (passage,
passenger, power).
 Be able to take a focused history, examination and
anlyse the symptoms and signs to diagnose labour.
 Describe the stage sand phases of labour.
 Discuss the mechanism of labour.
 Discuss the management of labour.

3. Labour (parturition)
 It Is the process where by with time regular uterine contractions, brings about
progressive affacment and dilatation of the cervix, resulting in delivery of the
fetus from the uterus and expulsion of the placenta at or beyond 24 (or 28)
completed weeks of pregnancy.
It is a social, psycological and economical event for the couple, family and
community.

4. Cervical dilatation: The cervix
begins dilating and stretching beyond the normal
dimensions and is measured in centimeters. (0-10cm).
Cervical effacement: softening,
thinning and shortening of the cervix. It is expressed in
percentage (0 – 100%)

5.  A 20 year old primigravida comes to maternity unit at 39 weeks gestation
complaining of regular uterine contractions, 3-4/10min. For the past 6 hours. The
contractions are becoming more frequent lasting 45-50 sec. she denies any vaginal
fluid leakage. The blood pressure, pulse and temperature are normal.
 Vaginal examination cephalic, head at s-1,90% affaced, 5 cm dilated, soft and
anterior. FH=133bpm .
What is your diagnoses?

6. Labour can occur at:
PTL
Term
Labour
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1 LNMP 24 W 28 W 37 W 40W 42W

7. Normal labour:
 Spontaneous expulsion, through the natural passages
(birth canal) of a single, mature (37-42 completed
weeks of pregnancy) Alive fetus, presenting by vertex,
within a reasonable time, without fetal or maternal
complications.

8. Components of
labour:

9. types of female pelvis

10. passengers
 The following will pass during labour (fetus, cord,
placenta and membranes). The most important to pass
is the head and shoulder

11. Moulding of the skull:
 means obliteration of the suture line between
the bones and overlapping of the un-united
bones of the fetal skull, and is measured by
degree.
Degree Clinical finding
+
++
+++
Suture line closed, no overlap
Overlap of suture line reducible
Overlap of suture line irreducible
As the degree of moulding increase- means there is CPD

12. Fetal attitude: is the relation of the fetal parts to each
other
 1- flexion attitude (common)
 2- extension attitude (rare).

13. Clinical course of labour
Onset of labour: not definitely known – however there
are several theories, but none of them is completely
proven.
Mechanical theories: - uterine distension
Hormonal theories:
1. Maternal :
o progesterone withdrawal
o oxytocin stimulation
o prostaglandins
o serotonin
2. fetal:
o fetal cortisol
o fetal membranes
3. Neuronal factors:
o sympathetic- alpha receptor stimulation

14. Diagnosis
A. symptoms:
1. True labour pains – colicky pain in the abdomen and back
are characterized by:
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ccoonnttrraaccttiioonnss rreegguullaarr IIrrrreegguullaarr
IInntteerrvvaall bbeettwweeeenn
ccoonnttrraaccttiioonnss aanndd
iinntteennssiittyy
PPrrooggrreessssiivvee ((iinnccrreeaassee iinn
ffrreeqquueennccyy aanndd
iinntteennssiittyy))
SShhoorrtt dduurraattiioonn,, nnoott
pprrooggrreessssiivvee
CChhaannggeess iinn tthhee cceerrvviixx AAssssoocciiaatteedd wwiitthh
eeffffaacceemmeenntt aanndd ddiillaattiioonn
ooff tthhee cceerrvviixx
NNoott aassssoocciiaatteedd wwiitthh
eeffffaacceemmeenntt aanndd ddiillaattiioonn
ooff tthhee cceerrvviixx
MMeemmbbrraanneess AAssssoocciiaatteedd wwiitthh bbuullggiinngg ooff
mmeemmbbrraanneess
NNoott aassssoocciiaatteedd wwiitthh
bbuullggiinngg ooff mmeemmbbrraanneess
RReessppoonnssee ttoo aannaallggeessiiaa NNoott rreelliieevveedd bbyy sseeddaattiioonn RReelliieevveedd bbyy sseeddaattiioonn
LLaabboouurr FFoolllloowweedd bbyy llaabboouurr NNoott ffoolllloowweedd bbyy llaabboouurr

15. 2. Show – blood stained mucous.
3. SROM
B. Signs:
o palpable or recorded uterine contraction
o effacement and dilation of the cervix
o formation of forewater

16. THE ACTIVE STAGE OF LABOUR –– WWHHEENN TTHHEE CCEERRVVIIXX
IISS MMOORREE TTHHAANN 33 CCMM DDIILLAATTEEDD AANNDD FFUULLLLYY EEFFFFAACCEEDD
STAGES OF LABOUR:
I-The First stage: stage of cervical effacement and dilatation
Definition: the first stage of labour refers to the period from the onset of true
uterine contractions to the fully dilation of the cervix, when the diameter of
the cervical os measures 10cm.

17. Duration:
o primigravida = 8-12 h
o multigravida = 6-8 h
Phases of the first stage:
 Latent phase: started when the cervix dilatated
slowly and reached to about 3cm.
A. in primigravida = 8h
B. in multigravida = 4h
 - Active phase: rapid dilatation of the cervix to
reach 10cm
A. in primigravda = 4h
B. in multigravida =2h

18. The active phase is divided into:
1. Accelerative phase
2. Slopping phase
3. Decelerative:
A. prolonged active phase
B. primary dysfunction: dilation in active
phase of<1cm/hr
C. secondary arrest: active phase dilation
stops or slow significantly.
N.B – in primigravida the cervix dilates from
above downwards, in multigravida
dilatation of the internal os, taking up of
the cervix and dilatation of the external
os occurs simultaneously.

19. Factors affecting cervical dilatation:
1. Contraction and retraction of the uterus.
2. The bag of fore-water.
3. Absence of membranes.
4. Fitting of the presenting part to the lower segment and the
cervix.
5. Pre-labour changes in the cervix (eg, softening)

20. II-The Second stage of labour: stage of
delivery of the fetus.
Definition: the second stage of labour refers
to the period from complete cervical
dilatation to the birth of the fetus.29-30
Duration:
A.in primigravida =1 h
B.in multigravida = ½ h
however the timing of the second stage is
very different to determine and
controversial and can be extended as much
as there is progress in descent and no harm
to the mother or fetus

21. The second stage of labour had two phases:
1. Passive phase – stage of descent of the presenting part and
dilatation of the vagina – due to contraction and retraction of
the uterine muscle.
2. Expulsive phase – stage of bearing down – due to contraction and
retraction of the uterine muscle and voluntary efforts by
diaphragm and abdominal muscles.

22. Mechanism of labour in vertex presentation:
Definition: The spontaneous adjustments of the
fetal position and attitude to affect efficient passage of
the fetus through the pelvis, marked by progressive
descent until delivery of the fetus.
Delivery of the fetal head:
A- Descent: is a continuous movement throughout
the process of delivery, however it becomes more
rapid in the second stage of labour, it is caused by:
o-Uterine contraction and retraction.
o-bearing down effort – mainly in the second stage of
labour

23. In normal pelvis, the fetal head enters with
the sagittal suture in the transverse
diameter (or occasionally oblique
diameter of the brim). If the sagittal
suture in between the symphysis pubis and
sacral promontory – both parietal bones
are felt vaginally at the same level – the
head is said to be (synclitic). In such case
the biparietal diameter (9.5cm) is the
diameter of engagement. However some
degree of lateral inclination of the head
over the shoulder – (Asynclitism) is present
normally as the head enters the pelvic
inlet.

24. *If the sagittal suture lies close to the sacrum and the anterior
patietal bone lies over the inlet (Anterior parietal bone
presentation) - Anterior asynclitism.
*If the sagittal suture lies close to the symphysis pubis and the
posterior parietal bone lies over the inlet (posterior parietal bone
presentation) – posterior asynclitism.

25. Causes of non-engagement:
 Erroneous dates (primigravida)
 Extra-uterine:
A. full bladder or loaded rectum
B. Pelvic tumours
C. Pendulous abdomen and marked lumbar lordosis.
D. High angle of inclination of the pelvis.
E. Contracted pelvis.
 -Uterine:
A. Poor uterine tone.
B. Congenital deformities.
C. Fibromyomata.
D. Placenta previa.

26.  -Fetal:
A. polyhydramnios.
B. Short umbilical cord(acutal or relative,
due to entanglement)
C. Large baby.
D. Deflexion attitude, and malposition.
E. Multiple pregnancy.
F. Hydrocephalus.
Engagement – can be assessed by abdominal
station in fifths during antenatal period,
and by abdominal and vaginal stations
during labour.

27. C.Increased flexion: as the head descends, it meets resistance
from the pelvic walls and floor and this leads to increased flexion of
the head. As the head flexed it brings the shortest longitudinal
diameter of the head (sub-occipito-bregmatic – 9.5cm) to pass
through the birth canal. Flexion is explained by the (two armed
lever theory).

28. D-Internal rotation: the internal rotation
occurs as the head descends through the
pelvic cavity. As the head enters the pelvic
inlet in transverse diameter will rotate 3/8
of the cycle to pass through the pelvic outlet
in antero-posterior diameter.
The rotation is favoured by the slopping
shape of the pelvic floor, angling the leading
point of the head (occiput) in downward and
forward direction, by the effect of the
contraction and retraction of the uterus.

29. E-Crowning, extension and delivery of the fetal
head:
The combined effect of descent and internal
rotation bring the presenting diameter to the plane
of the pelvic outlet, with the occiput lying under
the pubic arch and the sinciput at the lower border
of the sacrum or coccyx.
When the widest diameter of the fetal head is
embraced by the distended vulva, it is said to be
crowned.
The occiput remains under the pubic arch but the
sinciput sweeps forwards as the neck extends.

30. The head is acted upon by:
1. The downward and forward force of the
uterine contraction and retraction.
2. The upward and forward force offered by
pelvic floor resistance so the head passes
forwards i.e. extends vertex, forehead,
and face come out successively.
Frequently, especially in primigravida, the
soft tissues are not able to distend
equally so that tearing of the perineum
and adjacent tissues may occur unless
steps are taken to avoid it by making a
formal incision (episiotomy).

31. F-Restitution and external rotation:
Following delivery of the head the occiput
rotates to the lateral position, in the
opposite direction of internal rotation to
correct the twist of the head on the
shoulders produced by internal rotation. The
internal rotation of the shoulders inside the
pelvis transmitted to the delivered head
which in turn move one eight of a circle
outside the pelvis, in the same direction as
that of the restitution, so at the end the
occiput is towards one thigh and the face is
towards the other thigh.

32. Delivery of the shoulder and body:
The widest diameter of the shoulders,( the
bi-acromial diameter), pass the pelvic brim
at the time when the anterior rotation of
the head is occurring. Thus the anterior
rotation of the occiput is favourable for both
the head and the shoulders. Similarly
external rotation of the head is associated
with rotation of the shoulders to bring them
into the antero-posterior diameter of the
outlet. With further descent, the anterior
shoulder delivered first from under the
pubic arch, followed by posterior shoulder,
during which time lateral flexion of the
trunk is occurring. The trunk and buttocks
follow with the same or the next
contraction.

33. Even in the course of normal delivery, there are many variations
of the mechanisms, dependent on the variation in the size and
shape of the pelvis and of the fetal head.
III-The Third stage of labour: the stage of expulsion of the
placenta and membranes.

34. Duration: up to 30 minutes, however the
average length of the third stage of labour
is 10 minutes.
Mechanism: the third stage is made of two
phases:
1. The first phase: phase of placental
separation occurs through the spongiosa
layer of the decidua at the time of expulsion
of the baby or very soon afterwards. The
shearing force responsible for the
separation is the contraction and retraction
of the uterus, reducing the uterine volume
and the area of the placental site, as the
fetus is expelled.

35. 2. The second phase: phase of placental
expulsion – The separated placenta
descends from the upper (active) segment
into lower (passive) uterine segment,
cervix, and vagina by two mechanisms:
A. -Schultze mechanism:(80%)
The placenta delivered as an inverted
umbrella with it’s fetal surface presenting
first followed by the membranes with retro-placental
haematoma.
B.Mattews – Duncan mechanism: (20%)
The placenta delivered side way and it
presents with it’s inferior surface first.

36. Stage of
labour
Definition Duration
Stage I latent
phase
(affacment)
•Begins from the onset of regular
contractions.
•Ends with acceleration of cervical dilatation
•Prepares cervix for dilatation.
<20 hours in PG
<14 hours MG
Stage 1 active
phase
(dilatation)
•Begins with acceleration of cervical
dilatation.
•Ends at 10 cm dilatation
•Rapid cervical dilatation
<2/hours in PG
<1.5/ hrs in MG
Stage 2
(descent)
•Begins from 10cm dilatation
•Ends with delivery of the baby
•Descent of the fetus
<2 hours in PG
<1 hours in MG
Add 1 hour in epi
Stage 3
(expulsion)
•Begins with delivery of the baby.
•Ends with delivery of the placenta
•Delivery of the placenta
<30 min.

37. Management of labour
The management of labour should be
commenced during the antenatal period, and
the women should be classified as high or
low risk pregnancy. The medical or surgical
problems should be corrected as in case of
(anaemia, hypertension, urinary tract
infection), vaccination should be given if
necessary, and all investigations should be
performed and prepared such as (HIV, HCV,
Hbs Ag, blood grouping…….etc).

38. Also the patient should be advised to attend
the antenatal class (parenterful class) and
visit the hospital including the labour ward to
be familiar to the place and staff.
Once labour is commenced and the patient
arrived to the admission room the following to
be done:

39. A. -Taking history or reviewing the antenatal
file.
1-Last menstrual period – expected date of
confinement.
2-Time of onset of labour.
3-Frequency and duration of contraction (3-
4cm/10min).
4-Presence or absence of amniotic fluid
leakage.
5-Presence or absence of show or vaginal
bleeding.
6-Past obstetric history especially mode of
previous delivery, presentation, mode of
delivery, and weight of previous children.
7-Past medical or surgical history that may
affect labour or delivery, especially
diabetes, heart disease, respiratory
disease allergies, and any medication.

40. B-Examination:
1. .General:
a-pallor, oedema, varicosities, height, and built.
b-Vital signs (BP, P, T)
c-Examination of heart, lungs, breast and other
organs if necessary
2. .Abdominal Examination:
a-To determine fundal height in cm using tape
measure (to determine gestational age
clinically), fetal lie, presentation, engagement in
fifths, size of the fetus, amount of liquor, fetal
heart rate.
b-The frequency and duration of the contraction.

41. 3. .Vaginal Examination: to assess the following.
a-Cervical dilatation in cm and effacement in %.
b-Length of the cervix.
c-Consistency of the cervix
d-Position of the cervix
e-State of the membranes, amount and colour of
liquor.
f-fetal presentation, position and station.
g-pelvic architecture.

42. DO NOT DO VAGINAL EXAMINATION IN
CASES OF VAGINAL BLEEDING BEFORE
THE PLACENTA PREVIA IS EXCLUDED.
DO STERIL SPECULUM EXAMINATION IF
SUSPECTED PLROM, IF THE WOMAN IS
NOT IN LABOUR.
If the woman diagnosed as having active labour – to
be admitted to labour ward.
N.B- active labour means –regular strong and
frequent uterine contraction 3-4/10min lasting 45-50
sec, and the cervix is fully effaced and 2.5-3cm
dilated.

43. Arrival to the labour ward:
I-first stage of labour:
1-Ensure patient’s privacy by covering her with
sheaths or blankets.
2-Reassure and show great sympathy and interest.
3-Record maternal vital signs every hour (BP, P, T).
4-Take blood for grouping and cross match for high
risk patients.
5-Monitor:
a-high risk patients should have a continuous
electronic fetal heart monitoring.

44. b-low risk patients should have brief electronic fetal
heart monitoring if NORMAL, to be followed by
intermittent auscultation:
-first stage every 15min
-second stage every 5min
6-Limit oral intake to small amount of clear fluid or
frozen pineapple.
7-Give all patients in active labour Ranitidine
(Zentac) 150mg orally / 6hourly.
8-Nurse the patient in:
a-left lateral position for mediated patients.
b-sitting or semi-reclining for unmediated patients.

45. 9-Encourage spontaneous voiding, catheterization
may be necessary.
10-Test all urine specimen for proteins, sugar, and
acetone.
11-Give IV fluids during labour to avoid
dehydration
a-0.9% Nacl or hartmann’s solution at 80-
125ml/hr
b-Supplementation with 5% dextrose to prevent
ketosis and hypoglycemia.
12-Give analgesia/anesthesia as required.
a-Pethidine (50-150mg)IM.
b-Diamorphin (5-10mg)IM. Every 3-4 hours.
*avoid giving it too early in labour < 3-4cm cervical
dilation or too late when the delivery is expected
within 1-2hours.

46. *if given too late:
-inform the pediatrician
-give Naloxon (Narcon) 0.02mg IM to the neonate.
c-Use Entonox (NO2 50%+O2 50%) by mask if
available.
d-Use epidural analgesia in selected cases if
available such as Breech, Twins, preterm delivery.
e-Give anti-emetics such as Metoclopromide (5-
10mg)IM if necessary, but should not be routine.
13-Do vaginal examination to:
a-assess progress of labour every 2-4hr
b-or immediately after rupture of membranes
c-FHR abnormalities.

47. 14-Recall all the observations in labour in
Partogram.
15-Consider augmentation with syntocinon if
progress of labour is slow (partogram).
-1000 ml Hartmann’s solution or normal saline + 10
units syntocinon (pitocin)
-Begin the infusion using a pump at 4 milliunits per
minute and double the dose every 20 minutes to a
maximum of 32 milliunits/min.
-Or begin with 15 drops / min and increase the rate
by 10 drops every 30 minutes untill adequate
contractions.

48. II-second stage of labour:
Once the patient reach the second stage of labour and have
the desire to push down then:
1-Put the patient in lithotomy position or other positions clean
the vulva, and perineum with antiseptic solution.
2-Encourage organized pushing down which she is feeling to
do so
3. -Monitor the uterine contraction and fetal heart more
frequent.
4. -Use syntocinon if progress is slow and no contractions.
5. -When the head appears at the vulva, the perineum is
supported during uterine contraction by sterile pad to
promote flexion and prevent premature extension of the
head by pressing up on the sinciput until crowning occur.

49. 6. -After crowning the head is allowed to be
delivered by extension slowly in between the
contractions by sliding the perineum over the
face.
7. -DO episiotomy if necessary under local
anaesthetic ( 10-20 ml) of 1% lignocain, but
should not be routine.
8. -Wait for the next contraction to deliver the
shoulder and trunks.
9. -Clamp and deliver the cord and baby to be
handled to pediatrician.

50. III-Third stage of labour:
The management of third stage is aimed at:
1-Complete delivery of the after birth
(placenta and membranes).
2-Prevention of acute inversion of the uterus.
3-prevention of postpartum haemorrhage

51. A-Delivery of the placenta and membranes:
a-Conservative method: the left hand is
placed over the abdomen to detect any
change in the level of the fundus or sign of
placental separation and decent are
detected, the patient is asked to bear down
to deliver the placenta spontaneously.
Ergometrine 0.5mg or Syntometrine(5 units
syntocinon + 0.5mg Ergometrine) to be
given intravenouslly.

52. Signs of separation and decent of the
placenta:
1. -The body of the uterus becomes smaller,
harder, and globular.
2. -The fundal level rises in the abdomen because
the lower segment becomes distended by the
placenta.
3. -Suprapubic bulge may appear due to presence
of the placenta in the lower segment.
4. -Elongation of the cord out side the vulva.
5. -Sudden gush of blood from the vagina.

53. b-Active methods(prophylaxis against postpartum
haemorrhage)
1-Give Methargine 0.5 mg IM or Syntometrine
(5units oxytocin+0.5mg Methargine), at the time
of the anterior shoulder is free from symphysis
pubis or as soon as possible thereafter.
2-Deliver the placenta and membranes by control
cord traction by right hand, and the left hand is
placed on the suprapubic region, pushing the
uterus upwards.
N.B. USE SYNTOCINON RATHER THAN
METHARGINE IN CARDIAC AND
HYPERTENSIVE CASES.

54. IV-Post Delivery:
1-examine the placenta for their completeness,
anomalies, length, and number of vessels in the
cord and record the placental weight.
2-Suture the episiotomy or any laceration.
3-Estimate blood loss, count swabs, and take cord
blood for Hb, blood group, Rh, bilirubin, and
coomb’s test for Rh negative mother.
4-Check BP, P, T, Lochia and firmness of the
uterus before transferring the patient.
5-Continue an infusion of syntocinon through the
first hour if necessary.
6-Allow no food during the first hour, sips of water
may be taken, encourage nursing.

55. V-Care of the new born infant:
1. -Clearance of the new passages.
2. -Determine the Apgar score one and five minutes
- heart rate
- respiratory rate
- muscle tone
- colour
- reflex irritability
3-Care of the umbilical cord stump
4-General assessment of the infant to exclude any
congenital anomalies.
5-Identification of weight, estimate the gestational
age, dress it and put a mask to identify it.
6-Protect the baby against cold.

56. A-Delivery of the fetal head:
Enter the pelvis by flexion
Engagement
Increased flexion
Internal rotation
DESCENT Crowning
Extension
Restitution
External rotation
Delivery of the fetal head
B-Delivery of the shoulder and body: