Pregnancy with previous scar

1. PREGNANCY WITH
PREVIOUS
CESAREAN SECTION
MODERATOR- DR. BHARTI
PARIHAR(PROFESSOR)
PRESENTED BY- DR. POOJA GUPTA( RSO III
YEAR)

2. DEFINITION OF CESAREAN SECTION-
• It is an operative procedure to deliver the fetus after the period
of viability, through an incision on the abdominal wall and
uterus.

3. INDICATION FOR CESAREAN
SECTION
NON RECURRENT INDICATION(MORE COMMON) RECURRENT
INDICATIONS
MATERNAL FETAL
Cephalopelvic
disproportion
Fetal distress
Failed induction Malpresentation-
breech, brow, face
Non progress of labour Multiple pregnancy-
first twin with non
vertex presentation
Antepartum
hemorrhage-
1. major degree of
placenta previa
2. Abruption with
unfavourable cervix or
fetal distress
Cord prolapse
Cord presentation
Macrosomia, vasa
Contracted pelvis
Previous classical scar
Previous two or more CS
Previous uterine rupture
Previous hysterotomy
Cervical or vaginal
stenosis
Previous myomectomy
Previous vesico-vaginal
fistula repair

4. TYPES OF UTERINE INCISION-
• Lower segment transverse incision- most common
incision

5. • Indication of classical incision-
1. Lower segment unapproachable due to adhesions
2. Large fibroid in the lower segment
3. Post mortem cesarean section

7. WHY PREGNANCY WITH PREVIOUS
CESAREAN IS IMPORTANT-
• The most important concern in pregnancy with previous CS is
the decision regarding the mode of delivery.
• The most important risk in pregnancy with previous CS is the
risk of scar rupture
• Here, in post cesarean pregnancy scar refers to uterine scar.

8. DANGERS OF POST CESAREAN PREGNANCY
1. Scar rupture
2. Morbidly adherent placenta

9. • SCAR RUPTURE-
1.most dangerous complication
2.More risk in classical/hysterotomy scar than lower
segment transverse scar
3.Lower segment scar ruptures during labor
4.Classical scar ruptures during late pregnancy
5.Rupture may be complete or Incomplete/scar
dehiscence

10. TYPE OF SCAR RUPTURE
•Complete rupture- when all layers of the uterine
wall are separated.
•Incomplete rupture- when the uterine muscle is
separated but visceral peritoneum is intact.
Incomplete rupture commonly referred as
uterine dehiscence.

12. INCIDENCE OF SCAR RUPTURE
Prior uterine incision Estimated rupture (%)
Classical 2-9
T shaped 4-9
Low vertical 1-7
One low transverse 0.2-0.9
Mutiple low transverse 0.9-1.8

13. SCAR RUPTURE

14. • Chances of rupture will depend upon-
1. Type of cesarean section
• Lower segment transverse incision (most commonly
performed)
• classical incision (upper segment vertical)- highest chance of
rupture
• “J” shaped incision
• “T” shaped incision
• lower segment vertical incision

15. PREVIOUS UTERINE SCAR BEHAVIOUR
LSCS(LOWER SEGMENT TRANSVERSE SCAR) CLASSICAL( UPPER SEGMENT VERTICAL
SCAR)
Thin margins- better apposition Thick margin- unsatisfactory apposition
Suture line undisturbed- passive segment
(stretch and relax)
Loosening of sutures- active
segment(contract and retract)
Stretching of scar is along the line of
incision during pregnancy and labor
Stretching of scar is right angles to the
line of incision
Placental implantation over scar- less
chances
Placental implantation over scar- more
chances
Scar rupture rate- 0.2-0.9%
(sound scar, scar ruptures during labor and
less chance of maternal and fetal mortality)
Scar rupture rate- 2-9%
( weak scar, scar rupture during late
pregnancy, more incidence of maternal
and fetal mortality )

16. 2. Integrity of scar:- Factors determining the integrity are as
follows-
• Type of incision is single most important factor that determines
the integrity of scar( LSCS Scar is more sound than classical)
• Elective CS scar is more sound than emergency CS scar.
• Indication for CS- in prolonged labor &placenta previa scar
becomes weak, in CS with non recurrent indication then scar will
be strong.
• Skill of the surgeon- the scar is expected to become stronger if
done by a skilled or experienced surgeon.

17. • Repair of a wound with single layer or double layer does not
affect the integrity of scar
• Clean cut uterine wound heals well and scar become strong.
• Post operative complication- in puerperal sepsis, scar may be
weakened.

18. EFFECT OF INTER PREGNANCY INTERVAL ON NEXT
PREGNANCY
•MRI studies shows that at least 6 months are
required for complete uterine involution and
restoration of anatomy.
Interdelivery interval of less than 18 months
is associated with threefold increase risk of
symptomatic rupture during the trial of labor.

19. HEALING OF CESAREAN SCAR-
• In proper apposition , the wound heals by muscles and
connective tissue leads to a stronger scar formation
• otherwise, healing occurs by scar tissue only by
containing fibroblast- weak scar

20. HOW TO ELICIT SCAR TENDERNESS
• As the previous cesarean section is almost always LSCS,
tenderness should be elicited by the fingers or ulnar border of
hand along the transverse uterine scar very gently in the
suprapubic region.
• Skin scar may be transverse or vertical.
• During palpation of uterine scar
Look at the face of the mother to
Note the change in facial expression
For tenderness.

21. DIAGNOSIS OF IMPENDING SCAR
RUPTURE
SYMPTOMS
Pain in lower abdomen
persisting even in between
contractions
Frequency of urination,
tenesmus
Vaginal bleeding- may or may
not be present
SIGNS
PULSE- tachycardia
BP – normal or low
Scar tenderness- tenderness over the
uterine scar
Bulging at lower segment
Fetal distress
No progress of labor
Vaginal bleeding
USG- Bulging of amniotic sac through
the scar may be visible

22. DIAGNOSIS OF SCAR RUPTURE
•Symptoms-
1. Sudden cessation of pain abdomen following
excessive pain and sensation of something
giving away.
2. Cessation of pain may be followed by fainting.
3. Sometimes pain abdomen converts into dull
aching pain.
4. Vaginal bleeding
5. Hematuria

23. •Hemoperitoneum from a rupture uterus may
result in diaphragmatic irritation with referred
chest pain, this may mislead to the diagnosis of
pulmonary embolism/ amniotic fluid embolism.
•Rupture uterus can itself lead to amniotic fluid
embolism.

24. •Signs –
1. Features of shock
2. Tachycardia
3. Hypotension, excessive sweating and
restlessness
4. CTG Shows- variable deceleration which
may evolve into late deceleration and
bradycardia

25. PER ABDOMINAL EXAMINATION-
• Uterine contour is lost, instead two hard globular
structure which are palpable one is fetal head while the
other is contracted uterus.
• Fetal parts are palpable superficially
• Tenderness all over the abdomen
• Presence of free fluid in abdominal cavity.
• Absent FHS- most consisting finding.

26. PER VAGINAL EXAMINATION
• Excessive bleeding
• Reformation of cervix- curtain like structure
• Loss of station of presenting part

27. MORBIDLY ADHERENT PLACENTA

28. •Management of morbidly adherent
placenta – Cesarean
hysterectomy

29. MANAGEMENT
TRIAL OF LABOR AFTER CESAREAN
(T O L A C)
VAGINAL BIRTH
AFTER CESAREAN
SECTION
(V B A C)
EMERGENCY C S
E R C S
(ELECTIVE REPEAT CESAREAN
SECTION)

30. FOR WOMEN WITH A PRIOR CESAREAN
DELIVERY, THERE ARE THREE POSSIBLE
OUTCOME-
•VBAC( VAGINAL BIRTH AFTER CESAREAN)- A
successful trial of labor, this situation has the
lowest risk of complication for the mother and
baby.
•An unsuccessful trial of labor resulting in
cesarean section, this situation has the highest
risk of complication for the mother and baby.
•An elective repeat cesarean section

31. PRE-REQUISITES FOR TOLAC-
• VBAC should be allowed only in tertiary care center with the
following facilites-
1. Facility for performing emergency CS
2. Continuous monitoring during labor
3. Blood transfusion if needed
4. Maternal ICU and neonatal ICU
• Availability of expert obstetrician during labor to monitor the
progress of labor and to perform emergency CS if necessary
• Availability of anesthetic facility for emergency CS
• INFORMED CONSENT OF THE PATIENT

32. CANDIDATES FOR TOLAC ( ACOG
GUIDELINES)
• It should be previous lower segment transverse scar
• Not more than one previous LSCS
• No other uterine scar or previous uterine rupture
• Clinically adequate pelvis
• Good scar integrity
• Inter pregnancy interval >18 months
• Prior vaginal delivery favours successful TOLAC
• NO obstetric complication such as pre-eclampsia and placenta previa
in current pregnancy
• No malpresentation
• Average estimated fetal weight( rule out CPD)

33. TOLAC BASED ON SCAR THICKNESS
RISK SCAR THICKNESS
HIGH RISK <2mm
INTERMEDIATE RISK 2-2.4mm
LOW RISK >2.5mm

34. CONTRAINDICATION FOR TOLAC
• Previous classical scar
• Previous T/J shaped uterine incision
• Previous uterine rupture/hysterotomy
• Previous CS done for recurrent indication- contracted pelvis,
vaginal/cervical stenosis
• Medical/obstetric complication during present pregnancy(CPD,
placenta previa, severe pre eclampsia, bad obstetric history)
• Patient not giving consent for VBAC

35. BENEFITS OF VBAC
• Less hemorrhagic complications
• Less pain
• Early ambulation
• Rapid recovery in post natal period
• Short hospital stay
• Infectious morbidity is less
• Complication related to CS are avoided

36. RISK OF VBAC
• Risk of scar rupture
• Complication related to scar rupture-need for
emergency laparotomy or hysterectomy due to
hemorrhage, need for blood transfusion.
• Increased perinatal morbidity and mortality associated
with scar rupture

37. ROLE OF EPIDURAL ANALGESIA –
CONTROVERSY!!
According to ACOG epidural analgesia may
safely be used during TOLAC
•ADVANTAGE
1. Patient can be taken for emergency LSCS
during labor with epidural catheter
2. Instrumental deliveries can be easily
performed

38. •DISADVANTAGE-
1. Can mask pain resulting from uterine
scar rupture
2. Increased rate of instrumental deliveries

39. SUCCESS RATES OF VBAC-TOLAC – 60%- 80%
(ACOG)

40. INDUCTION OF LABOR
• Sweeping of membranes and foley’s catheter can be done
• Oxytocin is safer than prostaglandins
• Misoprostol should not be used in women with previous uterine
surgery
• Rate of uterine rupture recorded are-
misoprostol>dinoprostone>oxytocin
• ACOG recommends- the use of oxytocin and dinoprostone to be
avoided and misoprostol is contraindicated.

41. Avoid induction or Augmentation in women
with prior unknown incision type,
unfavorable cervix, pregnancy >40weeks.

42. AAFP GUIDELINES FOR TOLAC(JULY
2015)
Recommendation 1- all women with 1 previous cesarean section with a low
transverse incision are candidates for and should be offered TOLAC .
Recommendation 2- patient desiring TOLAC should be counseled that
their chance of a successful VBAC IS influenced by several factors.
Positive factors include maternal age less than 40 years, prior vaginal delivery,
particularly prior successful VBAC, favourable cervical factors, and non recurrent
indication for cesarean delivery
Negative factors include increased number of prior cesarean delivery, gestational
age>40 weeks, baby weight >4 kg & induction and augmentation of labor
Recommendation 3- prostaglandins should not be used for cervical
ripening or induction with TOLAC because they increase the risk for uterine rupture
and reduce the rate of successful vaginal delivery.

43. MANAGEMENT OF PATIENT ALLOWED FOR
VBAC
•Await spontaneous onset of labor, as
spontaneous labor has a high success for
vaginal delivery.
•Oxytocin can be used for augmentation of
labor with careful maternal and fetal
monitoring.

44. FIRST STAGE
•IV line is secured and blood sample is sent for
cross match
•Patient is kept nil orally
•IV fluids are given to maintain hydration( as
patient may be taken for emergency CS anytime
during labor)
•Epidural analgesia can be given
•Continuous CTG/FHR Auscultation- every 15

45. • Maternal monitoring- half hourly pulse, hourly BP,
check for scar tenderness
• Watch for sign and symptom of scar dehiscence and
rupture
• Good uterine contractions, early engagement of head,
progressive dilatation and effacement of cervix and
descent of fetal head are favourable factors indicating
successful vaginal delivery.

46. •PERFORM EMERGENCY CS if following are
present-
1.Symptoms and signs of scar dehiscence or
rupture
2.Failure of progress of labor-
a)<1 cm per hour dilatation over >4 hour
b)No head descent with >60 minutes pushing in
the second stage

47. SECOND STAGE
•FHR to be monitored every 5 minutes
•Watch for signs and symptoms of scar dehiscence
and rupture
•Prolonged second stage should not be allowed.
•If the patient does not deliver within 1 hour in
second stage, cut short with prophylactic forceps
and vacuum
•Shortening the second stage reduce the strain on

48. THIRD STAGE
•Active management of third stage of labor
•IV/IM oxytocin following delivery of baby,
delivery of placenta by controlled cord traction
•Watch for any excessive bleeding

49. CONTROVERSY……
• Routine exploration of scar after VBAC is controversial
• Usually routine digital examination of scar should not be done if
placenta is complete and uterus is well retracted without any
significant vaginal bleeding
• It may cause further dehiscence or rupture during palpation
• If uterus is well retracted and there is excessive vaginal
bleeding then only exploration of uterine scar to be done very
gently by experienced person.

50. FOURTH STAGE
•The patient to be kept under observation for 4
hours in labor room and then to be shifted to
postnatal ward.

51. If the patient has-
1. Excessive vaginal bleeding in absence of uterine atony
2. Rising pulse
3. Falling BP
4. Worsening pallor
resuscitate the patient, inform the senior
consultant on call and simultaneously prepare for exploration of
lower segment under anaesthesia in OT.
• In case of scar rupture , Emergency laparotomy is
performed.

52. ELECTIVE REPEAT CESAREAN
SECTION(ERCS)
• ACOG recommends delaying non-medically indicated deliveries
until 39 completed weeks
• ACOG guidelines for timing of ERCS-
1. Sonographic measurements taken before 20 weeks gestation
supports a gestation age more than or equal to 39 weeks.
2. Fetal heart sound have been documented for 30 weeks by
doppler ultrasound.
3. A positive serum or ß-HCG test result has been documented for
>36 weeks.