Please find the power point on Management and pathophysiology of Normal Labour . I tried to present it on understandable way and all the contents are reviewed by experts and from very reliable references. Thank you

1. Sunil Kumar Daha

2. DEFINITION
 Labor : series of events that take place in genital
organs to expel the product of conception (fetus,
placenta, membranes) out of womb through the
vagina into the external world.
 Delivery: the expulsion of viable fetus out of the
uterus (vaginal (spontaneous or aided) or
abdominal

3. NORMAL LABOR/
EUTOCIA
 spontaneous in onset and at term
 with vertex presentation
 without undue prolongation
 Natural termination with minimal aids
 without having any complications affecting the
health of the mother and/or the baby

5. ESTROGEN
 Increases release of oxytocin from maternal
pituitary
 Promotes synthesis of myometrial receptors for
oxytocin,PGincrease in gap junctions in
myometrial cells
 Stimulates synthesis of myometrial
contraction protein  actinomyosin through
cAMP.
 Increases excitability of myometrial cell

6. PROSTAGLANDIN
 Initiates and maintain labor
 Major site of production:
Amnion,chorion, decidual cells and
myometrium
 Enhances gap junction formation
 Triggered by estrogen, glucocorticoids,
separation or rupture of membrane

7. OXYTOCIN
 Peptide hormone
 Hypothalamus-posterior pituitary
 Fetal production: Maternal serum increase in
second stage of labor
 Oxytocin receptors: Fundal location, increase
during pregnancy
 Actions
1. Stimulate uterine contractions
2. Stimulate PG production from amnion/decidua

8.  TRUE AND FALSE LABOR
 True labor
o Painful contractions at regular
intervals at term
o Contraction frequency,
intensity, duration increases
gradually
o Associated with Show
o Progressive effacement and
dilatation of cervix
o Descent of presenting part
o Formation of “bags of water”
o Not relieved by enema/
sedatives (analgesics)
 False labor
o Dull pain confined to
groin and abdomen
o Pain interval doesn’t
shorten
o Pain intensity remains
same
o No cervical dilatation
o No hardening of uterus
o Relieved by enema or
sedative

9. DURING PREGNANCY…
 Marked hypertrophy and hyperplasia of uterine
muscles
 Length of uterus + cervix = 35 cm at term
 Uterus assumes pyriform/ ovoid shape
 Cervical canal occluded by thick, tenacious mucus
plug

10. UTERINE CONTRACTION IN
LABOR
 Irregular involuntary painless spasmodic uterine
contraction (Braxton-Hicks) throughout pregnancy which
changes during labor
 Pacemaker situated in : tubal ostia  contraction waves
initiate
 Pain of contraction distributed along the cutaneous nerve
distribution of T10 –L1

11. PATTERN OF
CONTRACTIONo Good synchronization of contraction waves from both
halves of the uterus
o Fundal dominance with gradual diminishing
contraction wave through midzone down to lower
segment in 10-20 sec
o Wave of contraction follow regular pattern
o Upper segment of uterus contracts longer and
stronger than lower part
o Intra-amniotic pressure rises beyond 20mm Hg
during uterine contraction
o Good relaxation occurs in between contraction(intra-
amniotic pressure less than 8)

12. RETRACTION
 Phenomenon of uterus in labor in which muscle
fibers are permanently shortened
 Effects of retraction:
1. Formation of lower uterine segment + dilatation and
effacement of cervix
2. Decent of presenting part  expulsion of fetus
3. Reduce surface area  separation of placenta
4. Effective homeostasis after separation of placenta

13. STAGES OF LABOR
 First phase
- latent
- Active
 Second phase
 Propulsive
 Expulsive
 Third phase
 Fourth phase

14. FIRST STAGE
 Concerned with formation of birth canal
 Main events:
1. Dilatation of cervix
2. Effacement of cervix
3. Lower uterine segment formation

15. FACTORS RESPONSIBLE IN
DILATATION
 Uterine contraction and retraction
Longitudinal fiber of upper segment
attach to circular fiber of lower
segment if uterus contracts
canal opens + shortens polarity of
uterus
 Fetal axis pressure
o longitudinal lie of fetus  circular
muscles contraction transmitted
from podalic pole to head
o Not in transverse lie
 Bag of membrane
 Vis-a-tergo

16. EFFACEMENT OF CERVIX
“processes by which muscular fibers of cervix pulled
upward and merge with fibers of lower uterine
segment”
 Primigravidae: effacement before dilation of
cervix
 Multiparae: effacement and dilatation occur at
same time

17. LOWER UTERINE
SEGMENT
 Formation of active upper segment and relatively
passive lower segment forms during labor

18. Friedman’s Curve
 Friedman's Curve describes progress of two variables
over time:
• dilation of cervix
• descent of baby
 Labor is “dysfunctional” when cervix stops dilating or fetal
descent stops or both
 Possible diagnosis of "failure to progress"
 C-section indicated
 May be due to CPD (Cephalo Pelvic Disproportion) or
epidural anesthesia

19. Friedman’s Curve

20. SECOND STAGE OF
LABOR
“Begins when cervical dilatation is complete and
ends with fetal delivery.”
 Median duration
 50 minutes in primigravida
 20 minutes in multiparous
 Uterine contractions and accompanying expulsive
forces last:
 60-90 seconds and
 recur every 60 seconds

21.  Propulsive phase:
 Period of full dilation until head touches pelvic floor
 Expulsive phase:
 Since the time mother has irresistible desire to ‘bear
down’ and push until the baby is delivered

22. DURATION OF LABOR
 Mean length of 1st and 2nd stage labor
 12 hours in primigravida
 6 hours in multipara

23. THIRD STAGE OF LABOR
 Includes separation, descent and expulsion of
placenta with its membrane.
 Signs of placental separation:
1. Hardening of uterus
2. Sudden gush of blood
3. Rise of Uterus (because the placenta, having separated, passes
down in the lower uterine segment and vagina)
4. Lengthening of umbilical cord
Signs of placental separation appear within 1-5 minutes within
delivery of newborn.

24. FOURTH STAGE OF LABOR
 The placenta, membranes and umbilical cord
should be examined for completeness and for
anomalies
 observation: 1 hour after birth of baby
 Laceration of birth canal(vagina and perineum):
 first degree laceration
 Second degree laceration
 third degree laceration
 fourth degree laceration

25.  Degree of Lacerations
 First degree laceration:
Involved the perineal skin, vaginal mucus membrane but not underlying
fascia and muscle
 2nd degree laceration:
Involve in addition, the fascia and muscle of perineal body but not anal
sphincter
 3rd degree laceration:
Extent further to involve the anal sphincter
 4th degree laceration:
Laceration extend through the rectum’s mucosa to exposed its lumen

26. MANAGEMENT OF FIRST STAGE
LABOR
1. Monitoring fetal well-being during labor
 Fetal heart should be monitored every 30 mins in 1st stage
and every 15 mins in 2nd stage of labor
2. Uterine contractions
 to evaluate the frequency, duration, and intensity of uterine
contractions.
3. Maternal vital signs
 Maternal temperature, pulse, and blood pressure are
evaluated at least every 4 hours
 with prolonged membrane rupture(>18 hours) antimicrobial
administration for prevention of group B streptococcal
infections is recommended
4. Subsequent vaginal examinations

27. CONTD..
5. Oral intake
 Food should be withheld during active labor and
delivery
6. Maternal position
 position that she finds most comfortable, which
will be lateral recumbency most of the time
7. Urinary bladder function
 Bladder distention-avoided, because it can hinder
descent of the fetal presenting parts

28. MANAGEMENT OF SECOND STAGE
LABOR1. Preparation for delivery
 Put the patient in dorsal lithotomy position or lying flat on bed
 Clean the vulva, and perineum with antiseptic solution
 Encourage organized pushing down which she is feeling to do so
2. spontaneous delivery
 With each contraction, perineum bulges increasing
 Ritgen maneuver- when head distends the vulva and perineum
enough to open the vaginal introitus to 25 cm or more
A towel-draped ,gloved hand –used to exert forward pressure on the chin of
fetus through the perineum
 This maneuver allow delivery of head and also favors the neck
extension so that head is delivered with small diameter

29. CONT..
 Clearing the nasopharynx:
Once the thorax –delivered and the newborn can inspire
Face quickly wiped and the nares and mouth cleared
 Nuchal cord :
Found in 25% of deliveries and ordinarily no harm
If coil of umbilical cord felt-it should be slipped over the
head if loose enough
If too tight, the loop should be cut between two clamps

30. CONT...
 Clamping the cord:
 Umbilical cord is cut between two clamps placed 4 to 5 cm from the foetal
abdomen and later an umbilical cord clamp-applied 2 to 3 cm from the fetal
abdomen
 Plastic clamp –safe
 Timing of cord clamping:
 If after delivery of the newborn –placed below the level of the vaginal
introitus for 3 min and Fetoplacental circulation – not immediately occluded
by cord clamping, then approx. 80 ml of blood shift from placenta to
neonate this reduces the frequency of iron deficiency anemia later in
infancy

31. MANAGEMENT OF THIRD
STAGE LABOR Delivery of the placenta:
-Traction on the umbilical cord must not be used to pull the placenta
out of uterus.
-uterine inversion is one of the complication associated with delivery
 Manual removal of placenta:
- Adequate analgesia is mandatory and aseptic surgical technique
should be used
-occasionally, placenta will not separate especially common in case
of preterm delivery
-if there is brisk bleeding and the placenta can not be delivered-
indicated

32. CONT...
1.Oxytocin
 Given before delivery of placenta will decrease blood loss(they
may entrap an undiagnosed, undelivered 2nd twins)
 The spontaneously labouring uterus is typically sensitive to oxytocin
and dosing should be titered to achieved adequate contraction
 After delivery of the foetus, dosing should be fixed
 It should be given as a dilute solution by continuous iv. Infusion or
im
 10 USP unit i.m. (oral not effective)
 T1/2 3-4 minutes- iv. Infusion (large bolus should not be given)

33. CONT..
CVS effect:
 IV bolus of 10 unit of oxytocin caused marked fall in BP with an
abrupt increase in CO.
 These hemodynamic changes could be dangerous for women
hypovolemic from haemorrhage or those with cardiac disease.
Water intoxication:
 Has antidiuretic action
 With high dose of oxytocin- produce water intoxication if the
oxytocin administered with large volume of electrolyte free aqueous
dextrose solution
 Oxytocin given with NS or ringer solution

34. 2. Ergonovine and methylergonovine:
 Ergot alkaloids
 Stimulation of myometrium contraction
 Given IV (0.1mg),IM or orally(0.25mg)
 They are dangerous for mother and foetus prior to delivery-
tendency of relaxation
 IV administration sometimes initiation of transient hypotension-
severe in gestational hypertension
3. prostaglandins:
 Analogs not used routinely for management of 3rd stage labour

35. MANAGEMENT OF FOURTH
STAGE LABOR
1. Examine the placenta for their completeness,
- anomalies, ( single umbilical arteryMultiple births)
- length, and
- number of vessels in the cord and record the placental weight
 Suture the episiotomy or any laceration
 Estimate blood loss, count swabs, and take cord blood for Hb, blood
group, Rh, bilirubin, and Coomb’s test for Rh negative mother
 Check BP, P, T and firmness of the uterus before transferring the patient
 Allow no food during the first hour, sips of water may be taken

37. FETAL SKULL
oMade of thin pliable tabular (flat) bones
forming the vault
oCompressible to some extent
oAreas of skull:
Vertex
Brow
Face

38. o Vertex: quadrangular area bounded
 anteriorly by bregma and coronal sutures
 Posteriorly by lambda and lambdoid suture
 Laterally by lines passing through parietal eminences
o Brow:
 One side anterior fontanels and coronal sutures
 Other side root of nose and supra-orbital ridges of either side
o Face:
 One side root of nose and supra-orbital ridges
 On other side junction of floor of mouth with neck

39. SUTURES
 Frontal: between the two frontal bones
 Sagittal: between the two parietal
bones
 Two coronal: between the frontal and
parietal bones
 Two lambdoid: between the posterior
margins of the parietal bones and upper
margin of the occipital bone

40. Diameter Measurement(cm) Attitude of
head
Presentatio
n
Suboccipito-bregmatic (nape
of neck to center of bregma)
9.5 cm Complete
flexion
Vertex
Suboccipito-frontal (nape of
neck to ant. end of ant.
fontanelle )
10.5 cm Incomplete
flexion
Vertex
Occipito-frontal(occipital
eminence to glabella)
11.5 cm Marked
deflexion
Vertex
Mento-verticle (mid point of
chin to highest point on sagittal
suture)
14 cm
(13cm in oxford
hand book)
Partial
extension
Brow
Submento-verticle (junction of
floor of mouth and neck to
highest point on sagittal suture)
11.5 cm Incomplete
extension
Face
Submento-bregmatic (junction
of floor of mouth and neck to
center of bregma)
9.5 cm Complete
extension
Face
ANTERO-POSTERIOR DIAMETER OF HEAD
THAT MAY ENGAGE

41. a. Biparietal diameter:
i. 9.5 cm
ii. Extends between two parietal eminences
b. Super-subparietal diameter:
i. 8.5 cm
ii. Extends from a point placed below one parietal eminence
to a point placed above other parietal eminence of
opposite side
c. Bitemporal diameter:
i. 8 cm
ii. Distance between antero-inferior ends of coronal suture
d. Bimastoid diameter:
i. 7.5 cm
ii. Distance between tips of mastoid processes
TRANSVERSE DIAMETER
CONCERNED IN MECHANISM OF
LABOR

42. Attitude of head Plane of engagement Circumference
Complete flexion Biparietal-suboccipito-bregmatic
Shape - almost round
27.5 cm
Deflexed Biparietal-occipito-frontal
Shape – oval
34 cm
Incomplete extension Biparietal-mento-vertical
Shape - bigger oval
37.5 cm
Complete extension Biparietal-submento-bregmatic
Shape - almost round
27.5 cm
CIRCUMFERENCE
Circumference of the plane of diameter of engagement
differs according to attitude of head
Circumference of head in different attitude:

43. MOULDING
“The alteration of the shape of the fore coming head
while passing through the resistant birth passage during
labor”
o There is little alteration in size of head as the volume
of content inside skull is incompressible
o An alternation of 4mm in skull diameter commonly
occur during normal delivery
o Disappears within few hours after birth

44.  MECHANISM:
 Compression of engaging diameter of head with corresponding
elongation of the diameter at right angle to it
 GRADING OF MOULDING
Grade 1:
 Bones touching but not overlapping
Grade 2:
 Bones overlapping but easily separated
Grade 3:
 Fixed overlapping of bones

45. IMPORTANCE OF MOULDING
 Slight moulding is inevitable and beneficial
Enables head to pass more easily through the
birth canal
 Extreme moulding may produce  Severe
intracranial disturbance in the form of tearing
of tentorium cerebelli or subdural
haemorrhage
 Shape of moulding gives information about
position of head occupied in pelvis

46. CARDINAL MOVEMENTS
OF LABOR

47. o the passage of the widest
diameter of the presenting part
to a level below the plane of the
pelvic inlet
o In the cephalic presentation with a
well-flexed head, the largest
transverse diameter of the fetal
head is the biparietal diameter (9.5
cm)
ENGAGEMENT

48.  Engagement can be confirmed clinically
by palpation of the presenting part
abdominally and/or vaginally
 The head is assumed to be engaged if
the leading edge has reached the ischial
spines and there is no significant
molding or scalp edema

49.  Head in Synclitism: the sagittal suture corresponds
to the diameter of engagement with the head enters
the brim
 Anterior asynclitism: Anterior parietal presentation
 Posterior asynclitism: Posterior parietal presentation
 Mild degree of asynclitism are common but severe
degrees indicate cephalopelvic disproportion
PRESENTATION

50.  downward passage of the presenting
part through the pelvis
 The greatest rate of descent occurs during the
deceleration phase of the first stage and during the
second stage of labor
 Forces involved:-
1. Pressure of amniotic fluid
2. Pressure of fundus upon breech with contraction
3. Maternal abdominal muscles
4. Extension and straightening of fetal body
DESCENT

51. o Occurs passively as the head
descends
o due to resistance related to the shape of bony pelvis
& by the soft tissues of the pelvic floor
o Although flexion of the fetal head onto the chest is
present to some degree in most fetuses antepartum,
complete flexion usually only occurs during the
course of labor
o A deflexed head presents a larger diameter, which
may be too large to negotiate the pelvic bone
FLEXION

52. o Rotation of the presenting part
from its original position (usually transverse with
regard to the birth canal) to the anteroposterior
position as it
passes through the pelvis
o As with flexion, internal rotation is a passive
movement resulting from the shape of the pelvis
and the resistance of the pelvic floor musculature
INTERNAL ROTATION

53. o Occurs once the fetus has
descended to the level of the
introitus
o This descent brings the base of the occiput into
contact with the inferior margin of the symphysis
pubis
o At this point, the birth canal curves upwards
o The fetal head is delivered by extension and
rotates around the symphysis pubis
EXTENSION

54. o After the fetal head deflexes (extends),
it rotates to the correct anatomic
position in relation to the fetal torso;
left or right rotation depends on the
orientation of the fetus
o Passive movement resulting from a release of the
forces exerted on the fetal head by the maternal bony
pelvis and its musculature and mediated by the basal
tone of the fetal musculature
EXTERNAL ROTATION

55.  Cunningham et.al., Williams OBSTETRICS,
24E, McGraw-Hill Education, 2014,
 DC Dutta’s textbook of Obstetrics
References

56. Thank you