Stages of labor

2. DEFINITION OF LABOR:
Series of event that takes
Place in an effort to expel viable
Product of conception (fetus ,
placenta and the membranes)
Out of the womb through
vagina to the outer world is
called labour.

3. The onset of labor is
defined as painful uterine
contraction accompanied by:
Rupture of membranes.
Bloody show.
Complete cervical effacement.

5. There are three stages in a
normal labour.
prior to the above stages
there is another stage called
preparatory stage.
The last stage is the fourth
stage that occurs after the
expulsion of placenta.

7. IN PRIMIGRAVIDA:
2-3 weeks before the
onset of labour.
IN MULTIGRAVIDA:
Few days before the
onset of labour.

8. This stage consist of :
1.LIGHTENING
The falling forward of
uterus with head sinking into
the pelvis due to relief of
pressure exerted by gravid
uterus upon diaphragm, lungs &
heart.

10. 2.Gradual Shortening of
Cervical canal.
this process commences
some days before the actual
onset of labour.
3. False labour pain.
Occurs more frequently in
primigravida than in multigravida.

14. DEFINITION:
It extends from the onset
of true labour pains to the
complete dilatation of cervix.
It is also called the stage
of cervical dilatation and
Effacement.

15. DURATION:
IN PRIMIGRAVIDA,
12 hours
IN MULTIGRAVIDA,
6-8 hours

16. PHENOMENA:
 Uterine contractions.
 Muco-sanguineous (blood
stained) mucoid discharge.
 Dilatation of cervical canal.
 Fixation of head.
 Rupture of membranes.

17. UTERINE CONTRACTION:
Also called true labour pains.
Duration of each contraction
lasts for 45 seconds.
Each contraction gradually
increases in intensity & then
diminishes in intensity.

18. INTRA UTERINE PRESSURE:
In normal labour the IUP is
35 mm Hg but may extend upto
50 mm Hg.
At first the pains are felt at
sacrum & may extend to lower
abdomen. May be associated
with nausea & vomiting.

19. Under the influence of
uterine contractions, uterus
becomes gradually divided into
two portions.
1.Upper segment
Active & becomes
progressively thicker as labour
advances.

20. 2. Lower segment with the
cervix.
Passive & becomes
thinner & stretched out to
receive the descending fetus
as labour advances.

21. The junction between the
Upper & lower segment is
Characterised by a ring of
Circular muscle fibres called
Physiologic retraction ring.
This ring becomes prominent
in obstructed labour, then it is
called pathologic retraction ring
or Bandl’s ring.

22. MUCO-SANGUINEOUS
DISCHARGE:
Just before the beginning
of labour, a small amount of
red- tinged mucus (a plug of
cervical mucus mixed with
blood) may be passed.

23. DILATATION OF CERVIX:
Mechanism of dilatation:
A well fitting presenting part
favours good uterine action &
smooth dilatation of cervix.
The uterine contractions
Cause pressure on the
membranes & Hydrostatic action
of amniotic Fluid dilates the
cervical canal.

24. After the rupture of
membrane, the pressure exerted
by the presenting part on the
cervix induce reflex uterine
contractions which are more
powerful than before rupture
which helps in rapid dilatation
of cervix.

25. Pattern of cervical dilatation:
Friedmann explained that
the cervical dilatation that
takes place during labour takes
the shape of a sigmoid curve,
if cervical dilatation is plotted
against time.

27. CERVICAL DILATATION CURVE
ACTIVE LATENT
VARIABLE
ACCELERATION
PHASE
PHASE OF
MAXIMUM SLOPE
DECELERATION PHASE

29. DEFINITION:
It extends from
complete dilatation of cervix
to the expulsion of fetus or
fetuses.
It is also called the
Stage of expulsion.

30. DURATION
IN PRIMIGRAVIDA,
1-2 hours
IN MULTIGRAVIDA,
½-1 hour.

31.  The nature of uterine
contractions gets stronger & are
severe than first stage.These
are of a bearing-down
character.
 The voluntary muscles, the
accessory muscles of labour
begin to contract & exert their
influence.

32.  The fetus is pushed down
Through the dilated cervix, &
Vagina relaxes & dilates.
 The vulva begins to widen
when the presenting part is
fixed under symphysis pubis.
this phenomenon is called the
Crowning of head - in vertex
presentation.

33.  At this stage the patient
Feels an inclination to micturate
& defecate which is due to the
Pressure exerted by presenting
Part on bladder & rectum.
 As the expulsion of head
Takes place, the patient exerts
One last effort, & the rest of
Fetus is born.

34. THIRD
STAGE

35. DEFINITION:
It extends from complete
Expulsion of fetus to the
Complete expulsion of placenta
& membranes.
It is also called the stage
Of placental delivery.

36. PHENOMENA:
 Characteristic uterine
contraction.
Separation of placenta.
Expulsion of placenta.
Control of haemorrhage.
Permanent contraction &
retraction of placenta.

37. PLACENTAL EXPULSION
DUNCAN’S
METHOD
SCHULTZE’S
METHOD

38.  Expulsion of placenta occurs
within a few minutes after the
birth of fetus.
 At this stage the uterus
Should be moderately hard in
Terms of tonicity, so that when
Placenta separates, the
Contractions & retractions of
Uterus will arrest haemorrhage
By closure of placental sinuses.

39. CONTROL OF HAEMORRHAGE:
It is due to 3 factors which
Are as follows:
1. Contraction & retraction of
uterus, constricting the vessels
passing though uterine wall to
placental site.
2.Occlusion of torn blood vessels
themselves.

40. 3. Formation of clots which
favours closure of lumen of
vessels.
After third stage there is
always a moderate bleeding
that doesn’t exceed 250 ml.
when labour is over the
patient may have rigour which
is vasomotor & not indication of
infection(physiological chill).

41. PRESENTED BY,
R.VIJAYALAKSHMI