This document provides an overview of induction of labor presented by Dr. Mansi Gupta. It defines induction and augmentation of labor and discusses gestational age classifications. The document outlines absolute and relative indications for induction as well as absolute and relative contraindications. It discusses elective induction of labor and recommendations from WHO on inducing labor in various situations. Evaluation before induction includes assessing maternal and fetal status and assigning a cervical scoring system. Methods for stabilizing induction and inducing labor in specific high-risk situations like IUGR, hypertension in pregnancy, and IUFD are presented.

1. INDUCTION OF LABOR
(Medical & Surgical
Methods)
PRESENTATION BY:
Dr Mansi Gupta

2. SOME IMPORTANT TERMS
•INDUCTION- stimulation of contractions before the
spontaneous onset of labor, with or without ruptured
membranes.
•AUGMENTATION- increasing the frequency &
improving the intensity of existing uterine
contractions in a patient who is in labor & not
progressing adequately, in order to accomplish
vaginal delivery.

3. •EARLY PRETERM- before 33+6wks
•LATE PRETERM- 34 to 36+6wks
•EARLY TERM- 37 to 38+6wks
•TERM- 39 to 40+6wks
•POST TERM- beyond 42 wks
•41-41+6wks - dilemma

4. •INDICATIONS??
??

5. INDICATIONS
• ABSOLUTE INDICATIONS
1. Hypertensive disorders- eclampsia/preeclampsia
2. Maternal medical conditions- DM, Renal dis, Chronic pulmonary
dis
3. PROM
4. Chorioamnionitis
5. Fetal compromise ( IUGR, Isoimmunisation, NRFHR,
Oligohydroamnios)
6. IUD
7. Posterm pregnancy(>42wks)

6. • RELATIVE INDICATIONS
1. Hypertensive disorder( Chronic HTN)
2. Maternal medical condition- SLE, GDM,
Hypercoagulable dis, ICP
3. Polyhydroamnios
4. Fetal anomalies req specialised neonatal care
5. Logistic factors- Risk of rapid labor, distance from
hospital, psychosocial; indications, Advanced cervical
dialation
6. Previous stillbirth
7. >41wks

7. CONTRAINDICATIONS
?????????

8. CONTRAINDICATIONS
ABSOLUTE
MATERNAL CONTRAINDICATIONS
Active genital herpes
Serious chronic medical conditions
Major degree cephalopelvic disproportion (such as women with pelvic deformities)
FETAL CONTRAINDICATIONS
Malpresentation (transverse or oblique lie)
Extreme fetal compromise
UTEROPLACENTAL CONTRAINDICATIONS
Cord presentation
Placenta previa
Vasa previa
Classical caesarean section, prior high vertical hysterotomy or myomectomy entering
endometrial cavity

9. RELATIVE CONTRAINDICATION
•Cervical carcinoma
•Malpresentation
•Grand multiparity
•Uterine overdistension (secondary to
polyhydramnios)
•Fetal macrosomia
•Low lying placenta
•Unexplained vaginal bleeding

10. WHAT IS ELECTIVE IOL???

11. •ELECTIVE IOL
Initiation of labor for convenience, in an individual with a term
pregnancy who is free of medical or obstetric indications.
Although not recommended or encouraged, it may be appropriate in
specific instances such as
1. H/O very short labors
2. Pt who lives far from hospital
RISK- Increased Caesarean( sp in nulliparous), Iatrogenic prematurity

12. • A recent meta-analysis included 16studies that compared induction and
expectant management for uncomplicated singleton pregnancies of at least
41weeks gestation. Compared with women allocated to expectant
management , those who underwent labor induction had lower caesarean
rates. There were no satistically significant differences in perinatal mortality
rates, NICU admissions, MSL, abnormal APGAR. Therefore after
41wks,elective labor inductionappears to be
justified.(gabbe)
• The trials had evaluated the effect of inducing labour at 37–40 weeks, 41
completed weeks, and 42 completed weeks of gestation, and the intervention
was compared with expectant management with fetal monitoring at varying
intervals. There were no statistical and clinical differences in the priority
comparisons and outcomes, except for a reduction in perinatal deaths when
labour was induced at 41 completed weeks.(WHO)

13. Induction of labour in women at or beyond term (WHO)
• Recommendations
1. Induction of labour is recommended for women who are known with
certainty to have reached 41 weeks (> 40 weeks + 7 days) of gestation. (low-
quality evidence. Weak recommendation.)
2. Induction of labour is not recommended for women with an uncomplicated
pregnancy at gestational age less than 41 weeks. (low-quality evidence. Weak
recommendation.)
• Remarks
1. Recommendation no. 1 above does not apply to settings where the
gestational age cannot be estimated reliably.
2. There is insufficient evidence to recommend induction of labour for
uncomplicated pregnancies before 41 weeks of pregnancy.

14. Induction of labour in women with GDM (WHO)
• Recommendation
1. If gestational diabetes is the only abnormality, induction of labour
before 41 weeks of gestation is not recommended. (very-low-
quality evidence. Weak recommendation.)
• Remark
1. Participants in the WHO technical consultation acknowledged that
labour induction may be necessary in some women with diabetes –
for example, those with placental insufficiency and uncontrolled
diabetes.

15. Induction of labour for suspected fetal
macrosomia(WHO)
• Recommendation
1. Induction of labour at term is not recommended for suspected fetal macrosomia
(low-quality evidence. Weak recommendation.)
• Remark
1. Confirmation of suspected macrosomia is based on reliable determination of fetal
age and weight, which requires ultrasound assessments early in pregnancy and then
at near term. considering that in under-resourced settings ultrasound facilities may
not be available or accessible to all women, the participants in the technical
consultation preferred not to recommend induction of labour for suspected
macrosomia, even though they acknowledged that in cases of confirmed macrosomia
induction of labour could reduce the incidence of clavicle fracture due to shoulder
dystocia.

16. Induction of labour in women with prelabour
rupture of membranes at term (WHO)
• Recommendation
1. Induction of labour is recommended for women with prelabour rupture of
membranes at term. (High-quality evidence. strong recommendation.)
• Remark
1. Participants in the WHO technical consultation noted that in the trials
included in the cochrane review, induction of labour had been initiated within
24 hours of rupture of membranes. They also noted that oxytocin should be
regarded as the first option for induction of labour in women with prelabour
rupture of membranes.

17. Induction of labour in women with uncomplicated
twin pregnancy at or near term (WHO)
• Recommendation
1. none.
• Remark
1. The participants in the technical consultation noted that
there was insufficient evidence to issue a recommendation on
induction of labour in women with an uncomplicated twin
pregnancy at or near term.

18. •About 70% of twin & higher multiple pregnancies
deliver between 35 & 37 weeks spontaneously
reducing the need for elective induction at 38 wks
•Some necessitate early delivery due to early onset
complications such as growth restriction, PET, where
decision has to be individualized depending on
severity of complication. No data is available to
assess the safety of induction before 37 weeks

19. HEART DISEASE
• There is little place for induction in heart disease because
1.it may misfire & a prolonged induction delivery interval may result in
infection or caesarean section
2.Anxiety due to induction may lead to worsening of heart disease
3.Risk of fluid overload & failure
• PGE2 can be used for cervical ripening but as it is a potent vasodilator
& causes marked rise in cardiac output,it can lead to pulmonary
edema.
• Amniotomy is generally deferred for fear of ascending infection
(chorioamnionitis)
• NOTE: restrict I/V fluids to 75cc/hr

20. Breech presentation
• Induction of labour is not generally recommended if a
woman’s baby is in the breech presentation.
• If external cephalic version is unsuccessful, declined or
contraindicated, and the woman chooses, not to have an
elective caesarean section, induction of labour should be
offered, if delivery is indicated, after discussing the
associated risks with the woman.

21. IUGR ( RCOG)
•When end diastolic flow is present , IOL at 37 week ,
provided other surveillance findings are normal
•When end diastolic flow absent or reverse :
• -Gestation> 34 weeks then IOL , if other surveillance
tests are normal [ BPP/CTG, Venous doppler ]
• -Gestation < 34 weeks then admission , close
surveillance , steroids
• If other surveillance tests abnormal- delivery by CS

22. Hypertensive disorders of
pregnancy (gabbe)
•GESTATIONAL
HYPERTENSION
Mild increased risk of
abruptio placenta
•MILD PRE-ECLAMPSIA
Disease progression follows no
predictable pattern
Increased chances of HELLP
syndrome

23. •SEVERE PREECLAMPSIA
-IOL at 34 weeks
If < 34 weeks
-pregnancy can be continued beyond 24 hours if
patient is stabilised . Consider steroids.

24. IUFD
[1]Combination Mifepristone and Misoprostol
-200mg Mifepristone 24-48 hours before induction
-Vaginal Misoprost - 100ug 4 hourly X 4 doses
• If POG >28 wks – 50ug 4 hourly X 4 doses
[2] Vaginal Misoprostol
- 13-17 wks 200ug 6 hourly X 4 doses
- 18-26 wks 100ug 6 hourly X 4 doses
- > 27 wks 25-50ug 4 hourly X 6 doses

25. STABALISING
INDUCTION??

26. STABILISING INDUCTION
• Describes when the presenting part is not within the pelvis
• This follows an external version for a transverse or oblique lie but
may also be undertaken with a longitudinal lie & a high head
• Indication must be critically reviewed to ensure requirement of
delivery immediately
• If delivery cannot be delayed, an infusion of oxytocin should be
commenced prior to amniotomy to ensure that contractions have
commenced & head is over brim
• Then the head is fixed by an assistant and controlled ARM is done
• NOTE: there are high chance of cord prolapse, & facilities for
immediate caesarean section should be available

27. EVALUATION BEFORE IOL
• MATERNAL
1.Confirm indication
2.Review contraindication
3.Perform clinical pelvimetry
4.Assign bishop score
5.Review risks, benefits and alternatives of IOL with pt.
• FETAL/NEONATAL
1.Confirm POG
2.Assess need to document fetal lung maturity status
3.EFW
4.Fetal lie & presentation
5.Confirm fetal well-being

28. CERVICAL SCORING SYSTEM
• Cervix assessed by digital vaginal examination prior to induction, with the aim to
gauge the ease with which induction will be achieved
• Cervical scoring was first described by Bishop in 1964, when he showed inverse
relationship between cervical score & time taken for the woman to be in
established labour
• Various modifications of Bishop’s original score have been suggested, & most
widely used is Calder’s modified Bishop score
• Scores below 6 show unfavourable cervix, where natural process of ripening has
not yet begun
• In women with scores above 6, artificial rupture of membrane is usually simple &
becomes a possible method of inducing labour, although ripening agents may still
be administered
• If the total score is more than 8,the probability of vaginal delivery after labour
induction is similar to that after spontaneous labour.

29. BISHOP’S SCORE (BISHOP 1964)
• TOTAL SCORE:13, FAVOURABLE SCORE 6-13, UNFAVOURABLE SCORE
0-5

30. MODIFIED BISHOP SCORE (CALDER 1974)
• TOTAL SCORE: 12, UNFAVOURABLE 0-5, FAVOURABLE 6-12

31. FACTORS FOR
SUCCESSFUL
IOL???

32. FACTORS FOR SUCCESSFUL IOL
1. POG- near term
2. Bishop score - >=6
3. Cervical ripening- favourable in parous and PROM
4. BMI <30
5. Birth weight <3.5kgs
6. Presence of fetal fibronectin in vaginal swab-
>50ng/ml
7. Senstivity of uterus- positive oxytocin senstivity

33. PREINDUCTION CERVICAL RIPENING
•Enhancing the cervical favorability by different
pharmacological and mechanical methods.
•Some of the techniques described may have benefits
when compared with oxytocin induction alone. Some
are also quite successful for initiating labor. That said,
few data support the promise that any of these
techniques results in a reduced cesarean delivery rate
or in less maternal or neonatal morbidity compared
with that in women in whom these methods are not
used.

36. METHODS OF IOL
PHARMACOLOGICAL METHODS MECHANICAL METHODS
1.OXYTOCIN
2.PROSTAGLANDINS
E2- Dinoprostone, Prepidil gel and Cervidil time-
released vaginal insert
E1- Misoprostol, Cytotec
3. ESTROGEN
4. RELAXIN
5. HYALURONIC ACID
6. PROGESTERONE RECEPTOR ANTAGONISTS-
Mifepristone
1. MEMBRANE STRIPPING
2. AMNIOTOMY
3. MECHANICAL DIALATORS- Laminaria tents
Dilapan
Lamicel
4. TRANSCERVICAL BALLOON CATHETERS-
with extra-amniotic saline infusion
With concomitant oxytocin administration

37. PHARMACOLOGI
CAL METHODS

38. OXYTOCIN
• PHARMACOLOGY- Nonapeptide hormone
Given IV or IM ( orally GI enzymes deactivate it)
t ½- 3-6min
Duration of action- 20min
Steady plasma conc reached in- 30-40min
Preserved at- 2-8* C
• MODE OF ACTION-
Myometrial oxytocin receptor concentration increases maximum (100-200 fold) during labor.
Oxytocin acts through receptor and voltage-mediated calcium channels to initiate myometrial
contractions. It stimulates amniotic and decidual prostaglandin production.
The uterine contractions are physiological, i.e. causing fundal contraction with relaxation of the
cervix.
Little change in myometrial sensitivity to oxytocin from 34 weeks to term; however, once
spontaneous labor begins, the uterine sensitivity to oxytocin increases rapidly. This physiologic
mechanism makes oxytocin more effective in augmenting labor than in inducing labor, and
even less successful as a cervical ripening agent.

39. • PREPRATIONS:
(i) Synthetic oxytocin (Syntocinon-Sandoz or Pitocin-Parke-Davis) –
only oxytocic effect without any vasopressor action. Ampules - 5 IU/mL.
(ii) Syntometrine (Sandoz)—
Syntocinon 5 IU + Ergometrine 0.5 mg
(iii) Desamino-oxytocin—
Not inactivated by oxytocinase
50–100 more effective than oxytocin
Buccal tablets - 50 IU.
(iv) Oxytocin nasal solution-
40 units/mL.

40. •DOSAGE
1ml amp=5U
1. Conventional
low dose
regimen= 0.5-
1.5 mU/min
2. High dose
regimen= 4-6
mU/min

41. CALCULATION OF DOSE DELIVERED IN MILLIUNITS
(mu) & ITS CORRELATION WITH Drops/min

42. DOSING INTERVAL ??
• Rates of cesarean delivery for dystocia or fetal distress were not
statistically different
• 20-minute regimen for augmentation was associated with a
significant reduction in cesarean delivery for dystocia (8 versus 12
percent, P = .05).
• Incidence of uterine hyperstimulation was greater with the 20-
minute regimen for induction compared with the 40-minute
regimen (40 versus 31 percent; P = .02) . But did not result in an
increased rate of cesarean delivery for nonreassuring fetal status.
• Neonatal outcomes were unaffected by the dosing interval.

43. MAXIMAL DOSAGE
Maximal effective dose to achieve adequate
contractions in all women is different.
If contractions are not adequate and fetus status
is reassuring and labor has arrested, an oxytocin
infusion dose >48mU/min has no apparent risks
(Williams)

44. •OBSERVATIONS DURING OXYTOCIN INFUSION
1. Rate of flow – counting no. of drops /min
2.Uterine contractions –
-no. of contractions/ 10min
-intensity of contraction
-period of relaxation
3. FHR monitoring
4. Asses progress of labor
5. Maternal parameters

45. RISKS
1.UTERINE OVERACTIVITY-
Hyperstimulation –
• persistent pattern of >4 contractions(WHO) in 10 min
• uterine contractions lasting at least 1min(WHO) (hypertonus) or
• contractions of normal duration occurring within 1 minute of each other
- with or without fetal heart rate changes.
Tachysystole - hyperstimulation without FHR changes.
Hyperstimulation syndrome - any of above with FHR abnormalities.
1. Uterine tachysystole is defined as > 5 contractions in a 10-minute period. It
should always be qualified by the presence or absence of fetal heart rate
abnormalities.
2. Uterine hypertonus, hyperstimulation, and hypercontractility are terms no
longer defined, and their use is not recommended.

46. •One of the advantages of oxytocin administration is that if
uterine hyperstimulation is encountered, the infusion can
quickly be stopped, resolution of such uterine overactivity.
•Placing the woman in the left lateral position,
administering oxygen, and increasing intravenous fluids
may be of benefit.
• If FHR tracing abnormalities persist and uterine
hyperstimulation is ongoing, the use of a tocolytic, such as
terbutaline, may be considered.
•Oxytocin may then be reinitiated if appropriate once
uterine tone has returned to baseline and fetal status is
reassuring.

47. 2. WATER INTOXICATION
Oxytocin is structurally and functionally related to vasopressin(ADH). It binds
to vasopressin and oxytocin receptors in the kidney and the brain.
Oxytocin can have an antidiuretic effect at high doses and can, in extreme
situations, result in water intoxication.
Severe symptomatic hyponatremia can result if oxytocin is administered at
high concentrations (e.g., 40 mU/min) in large quantities of hypotonic
solutions (more than 3 liters) for prolonged periods of time.
Symptoms of severe acute hyponatremia include headache, anorexia, nausea,
vomiting, abdominal pain, lethargy, drowsiness, unconsciousness, grand mal
seizures, and potentially irreversible neurologic injury. Fortunately, this side
effect is extremely rare even with high dose oxytocin regimens.

48. 3. HYPOTENSION
Historically, bolus injections causes hypotension.
Current practice for labor management is administration by infusion
pump or slow drip.
MAP & PVR have been noted to decrease 30% and 50%, respectively,
after oxytocin bolus injection of 5 -10U. This caused increases of 30%
in HR, 25% in SV, and 50% in CO when compared with patients
receiving slow dilute infusions.
However, a more recent reports revealed that a 10-IU bolus of
oxytocin given in the third stage of labor was not associated with
adverse hemodynamic responses compared with oxytocin given as
an infusion.

49. 4. UTERINE RUPTURE
Rare and in most instances occurs in women with
prior uterine surgery such as cesarean delivery or
myomectomy.
However most studies suggest that the use of
oxytocin for labor induction or augmentation in
not associated with a significant increase in the
risk of uterine rupture in women with a prior
cesarean delivery

50. •INDICATIONS OF STOPPING THE INFUSION
1.Tachysystole
2.Hypertonus
3.Fetal distress
4.Untoward maternal symptoms

51. WHO
•Recommendation
1. If prostaglandins are not available, intravenous oxytocin
alone should be used for induction of labour. Amniotomy
alone is not recommended for induction of labour.
(moderate-quality evidence. Weak recommendation.)
•Remark
1. Immediately after the initiation of intravenous oxytocin, it
is advisable to monitor closely the oxytocin infusion rate,
response of the uterus to oxytocin, and fetal heart rate.

52. PROSTAGLANDINS
• Dissolution of collagen bundles and an increase in submucosal water content of
the cervix. These changes in cervical connective tissue at term are similar to
those observed in early labor.
• PGs are endogenous compounds found in the myometrium, deciduas, and fetal
membranes during pregnancy. Paracrine/autocrine hormones as they act on
locally at their site of production.
• t1/2 - 1-2min
• The chemical precursor is arachidonic acid.
• Prostaglandin analogs were originally given by IV and oral routes. Later, local
administration of prostaglandins in the vagina or the endocervix became the
route of choice because of fewer side effects and acceptable clinical response.
• PGs promote myometrial contraction irrespective of the duration of gestation
Side effects of all PG formulations and routes may include fever, chills, vomiting,
and diarrhea.

53. • Caution in-
1. Hypersensitivity
2. Ruptured membranes
3. Glaucoma
4. Asthma
5. Patients with compromised cardiovascular, renal & hepatic function

54. PROSTAGLANDIN E2
1. Gel – Prepidil/Cerviprime—is available in a 2.5-mL syringe for an
intracervical application of 0.5 mg of dinoprostone.
With the woman supine, the tip of a prefilled syringe is placed intracervically,
and the gel is deposited just below the internal cervical os. After application,
the woman remains reclined for at least 30 minutes. Doses may be repeated
every 6 hours, with a maximum of 3 doses recommended in 24 hours.
Oxytocin should not be initiated until 6 to12 hours after the last dose.

56. 2.Time-release vaginal insert - Cervidil—is also approved for cervical
ripening. This is a thin, flat, rectangular polymeric wafer held within a small,
white, mesh polyester sac.
The sac has a long attached tail to allow easy removal from the vagina.
10 mg of dinoprostone designed to release approximately 0.3 mg/hr during
a 10-hour period.
Used as a single dose placed transversely in the posterior vaginal fornix.
Lubricant should be used sparingly, if at all, because it can coat the device
and hinder dinoprostone release.
Following insertion, the woman should remain recumbent for at least 2
hours. The insert is removed after 12 hours or with labor onset and at least
30 minutes before the administration of oxytocin.
• Advantage - may be removed with the onset of active labor, rupture of
membranes, or with the development of uterine hyperstimulation.

57. VAGINAL INSERT- CERVIDIL

58. 3. SUPPOSITORY- 10mg
• Indicated for pregnancy termination between 12 and 20 weeks
• Evacuation of the uterus after fetal demise up to 28 weeks.
4. PGE2 ORAL TABLETS (0.5mg)
Almost as effective as oxytocin for induction
Usual regimen is 0.5mg(1 tablet) followed by 1mg (2 tablets) after 1 hour.
The successive hourly doses are then adjusted between 0.5 to 1.5 mg according
to the patient’s response
The dose increments are made by 0.5mg, at a time until labour is well
established
It is abandoned if labour is not established after 8 hours
Adverse effects include vomiting & diarrhoea,fever

59. 5. PGE2 vaginal tablet (3mg)
repeated after 6-8 hrs if required
Remain lying for 30 minutes after administration
6. PGE2 vaginal gel (1-2mg)
repeated after 6 hrs if required
Store in refrigerator at 2-8°C
Remain supine for 15 mins after administration

60. PROSTAGLANDIN E1- Misoprostol
• Cytotec—is a synthetic prostaglandin E1 that is approved as a 100-
or 200-μg tablet
• First used for peptic ulcer prevention.
• It is available as 25µg, 100µg, 200µg & 600µg tablets
• Route: Oral, vaginal and sublingual route for induction. Rectal route
is used to prevent and treat postpartum hemorrhage.
• Bioavailability: Extensively absorbed from the GIT
• Metabolism: De-esterified to prostaglandin F analogs
• Half life: 20–40 minutes, with peak plasma levels at 10-15 minutes
• Excretion: Mainly renal 80%, remainder is fecal: 15%

61. Oral misoprostol versus vaginal misoprostol
(WHO)
• Oral and vaginal misoprostol were similar with regard to all but one
of the priority outcomes: compared with vaginal misoprostol, oral
misoprostol was associated with a lower risk of Apgar score being less
than seven at 5 minutes of life

62. Oral or vaginal misoprostol versus
sublingual/buccal misoprostol (WHO)
• Trials indicate that vaginal and sublingual/buccal misoprostol are
similar with regard to all the priority outcomes. Data on oral versus
sublingual/buccal misoprostol are limited and no firm conclusions can
be drawn from them

63. (WHO)
• Recommendations
1. Oral misoprostol (25 µg, 2-hourly) is recommended for induction of labour.
(moderate-quality evidence. strong recommendation.)
2. Vaginal low-dose misoprostol (25 µg, 6-hourly) is recommended for
induction of labour. (moderate-quality evidence. Weak recommendation.)
3. Misoprostol is not recommended for women with previous caesarean
section. (low-quality evidence. strong recommendation.)

64. • ADVANTAGES:
• It is cheap, stable at room temperature
• Long shelf life
• Easily administered (oral, vaginal or rectal)
• Less side effects
• Induction delivery interval is short
• Need for oxytocin augmentation is less
• Failure of induction is less
• RISKS:
• Uterine tachysystole (incidence 31-49%) with or without FHR changes are more
common
• Hyperstimulation (8%)
• Rupture of uterus, rare
• Meconium staining of liquor

65. MIFEPRISTONE
• It is a 19-norsteroid with potent competitive antiprogestational & significant
antiglucocorticoid as well as antiandrogenic activity
• It is available as 200mg tablet
PHARMACOKINETICS:
• Active orally
• Bioavailability 25%
• Metabolised in liver
• t1/2 - 20-36 hours

66. • MECHANISM OF ACTION:
As it has greater affinity for progesterone receptor, it blocks the action of
progesterone at the cellular level.
Fall in level of progesterone is considered as important event in the onset of
spontaneous labour.
• DOSAGE:
• 200 mg orally
• It decreases induction delivery interval
• There is reduced need for prostaglandins

67. Nitric Oxide Donors
• Cervical NO metabolite concentrations are increased at the beginning of uterine
contractions.
• Cervical NO production is very low in postterm pregnancy
• NO donors - isosorbide mononitrate and GTN
1. Induces cervical COX-2
2. Brings about cervical ultrastructure rearrangement similar to that seen with
spontaneous cervical ripening.
Despite this, clinical trials have not shown NO donors to be as effective as PGE2 for
cervical ripening.
Addition of isosorbide mononitrate to either dinoprostone or misoprostol did not
enhance cervical ripening either in early or term pregnancy nor did it shorten time
to vaginal delivery.
Metaanalysis-do not appear to be useful for cervical ripening during labor induction.

68. ESTROGEN
• Parturition studies in sheep showed that there is a prelabor rise in estrogen
associated with a decrease in progesterone - stimulate prostaglandin
production - initiate labor.
• Through this mechanism, estrogen has been suggested and studied as a
cervical ripening agent and labor induction agent.
• This approach has limited widespread clinical applicability, because there is no
discussion of rates of vaginal delivery achieved within 24 hours or cervical
status change after 12 to 24 hours.
• Of note, the investigators reported that when comparing estrogen with
placebo, there were no differences in the rate of cesarean deliveries or in
uterine hyperstimulation between groups.
• Not currently used in common practice as an induction agent
• Insufficient evidence to draw any conclusions regarding its efficacy.

69. RELAXIN
• Protein hormone thought to have a promoting effect on cervical ripening through
connective tissue remodeling.
• Source - corpus luteum of pregnancy.
• Advantage – less risk of uterine hyperstimulation.
• Most research on induction of labor with relaxin has used porcine or bovine
preparations and demonstrated improved efficacy over a placebo for cervical
ripening.
• With the advent of DNA technology, human recombinant relaxin has become
available for evaluation. Two studies totaling 113 women who received human
recombinant relaxin for induction of labor compared with placebo showed no effect
on cervical ripening or labor induction.
• The place of relaxin as an induction or cervical priming agent is unclear, and further
trials are needed to determine its effect and place in current clinical practice.147

70. HYALURONIC ACID
• The cervix is a fibrous organ composed principally of hyaluronic
acid, collagen, and proteoglycan.
• Hyaluronic acid increases as pregnancy progresses, peaks after the
onset of labor, and decreases rapidly after birth of the infant.
• The increase in the level of hyaluronic acid is associated with an
increase in tissue water content of the cervix, which is one of the
mechanisms involved in cervical ripening.
• In the past, investigators postulated that cervical injection of
hyaluronic acid would lead to cervical ripening.
No data are available to assess its use for cervical ripening or labor
induction.

71. METHODS THAT ARE NOT RECOMMENDED
•Herbal supplements
•Acupuncture
•Homeopathy
•Castor oil hot baths and enemas
•Breast stimulation
AVAILABLE EVIDENCE DOES NOT SUPPORT ITS USE IOL

72. MECHANICAL
METHODS

73. • They were among the first methods used for labor induction.
• Advantages
1. Less costly
2. Less hyperstimulation
3. Easy to store
4. Result in fewer side effects for mother and fetus
• Disadvantages
1. Risk of infection
2. Disruption of a low-lying placenta
3. Some maternal discomfort on manipulation of the cervix.

74. MEMBRANES STRIPPING
• Digital separation of the chorioamniotic
membrane from the wall of the cervix and
lower uterine segment.
• First reported in 1810 by Hamilton in
England.
• For membrane stripping, the fetal vertex
should be well applied to the cervix, and the
cervix should be dilated sufficiently to allow
introduction of the examiner’s finger.
• This process of membrane stripping is
presumed to cause the release of
endogenous prostaglandins from the
adjacent membranes and decidua, as well as
from the cervix (FERGUSON REFLEX).

75. •Many investigations have been conducted using routine
membrane stripping at 38 or 39 weeks to either prevent
prolonged pregnancies or decrease the frequency of more
formal inductions occurring after 41 weeks.
•A metaanalysis including 19 trials demonstrated that routine
membrane stripping at term will
1. Reduce the interval to spontaneous labor by 3 days
2. Decrease the frequency of pregnancies continuing beyond
41 and 42 weeks
3. Lower the frequency of formal induction.

76. • There was no difference in the maternal or neonatal infection rate, or the rates
of membrane rupture or cesarean delivery.
• Complications
1. Rupture of membranes
2. Hemorrhage from disruption of an occult placenta previa
3. Development of chorioamnionitis.
There does not appear to be a contraindication to membrane stripping in Group
B streptococcus (GBS)–colonized women.
In accordance with Centers for Disease Control and Prevention guidelines,
antibiotic prophylaxis should be administered to any GBScolonized woman once
labor ensues or membrane rupture occurs.

77. WHO
• Recommendation
1. Sweeping membranes is recommended for reducing formal induction of
labour. (moderate quality evidence. strong recommendation.)
• Remarks
1. The panel acknowledged that maternal discomfort and bleeding associated
with the procedure should be balanced with the anticipated benefits. since
the interval between intervention and result (i.e. sweeping membranes and
initiation of labour) can be longer than with formal methods of induction of
labour, this intervention would be suitable for non-urgent indications for
pregnancy termination.
2. Regarding breast stimulation, sexual intercourse and other similar methods
of preinduction of labour, the participants in the technical consultation agreed
that there was insufficient evidence for recommending those methods.

78. AMNIOTOMY ( Artificial Rupture of
Membranes)
• Technique involving the perforation of the chorioamniotic membranes.
• It is used as a method of induction, either following prostaglandin with an
unfavourable cervix or as an initial procedure in women with favourable
cervical scores
• MECHANISM OF ONSET OF LABOUR:
1. Streching of cervix
2. Separation of membranes
(liberation of prostaglandins)
1. Reduction of amniotic fluid volume

79. • EFFECTIVENESS DEPENDS ON:
• State of cervix
• Station of presenting part
• ADVANTAGES:
• High success rate
• Chance to observe the amniotic fluid for blood or meconium
• Access to use fetal scalp electrode or intrauterine pressure catheter
or fetal scalp blood sampling
• LIMITATIONS:
• It cannot be employed in an unfavourable cervix (long, firm cervix
with os closed). The cervix should be atleast one finger dilated

80. • INDICATIONS:
• Abruptio placenta
• Chronic hydramnios
• Severe preeclampsia-eclampsia
• In combination with medical induction
• To place scalp electrode for electronic fetal monitoring
• CONTRAINDICATIONS:
• Intrauterine fetal death
• Maternal AIDS
• Genital active herpes infection

81. • IMMEDIATE BENEFICIAL EFFECTS OF ARM:
• Relief of maternal distress in hydramnios
• Control of bleeding in APH
• Relief of tension in abruptio placenta & initiation of labour
• HAZARDS OF ARM:
• Chance of cord prolapse
• Amnionitis
• Accidental injury to placenta, cervix, uterus, fetal parts or vasa previa
• Liquor amnii embolism

82. PROCEDURE
• Indoor procedure
• Patient in lithotomy position after emptying her bladder
• Two fingers are introduced into the vagina smeared with antiseptic ointment.
The index finger is passed through the cervical canal beyond the internal os.
The membranes are swept free from the lower segment as far as reached by
the finger
• With one or two fingers still in the cervical canal with palmar surface
upward,a long Kocher’s forceps with blades closed or an amnion hook is
introduced along the palmar aspect of fingers upto the membranes
• The blades opened to seize the membranes and are torn by twisting
movements. Aminohook is used to scratch over the membranes

84. • This is followed by escape of amniotic fluid
• Head not engaged-assistant should push the head to fix it to brim to prevent
cord prolapse
• Head deeply engaged-gentle pushing of head up,facilitates escape of desired
amount of amniotic fluid
• After the membranes rupture, following are to be assessed
• 1) Colour of amniotic fluid
• 2)Status of cervix
• 3)Station of head
• 4)Detection of cord prolapse
• 5)Quality of FHR

85. TRANSCERVICAL BALLOON CATHETARS
•A deflated Foley catheter, usually a 16 French(gabbe)
26 F(Williams) 30 mL balloon, can be passed through an
undilated cervix into the extra-amniotic space and then
inflated. The balloon is then retracted to rest against the
internal os.
• To add more traction, pressure may be applied by attaching
a weight such as a liter of intravenous fluid to the end of
the catheter and suspending it with the force of gravity or
by taping the catheter under tension to the patient’s inner
thigh. The benefit of traction has not been proven, and may
confer no added clinical benefit.

86. • No increased risk of preterm delivery in subsequent pregnancies following
the placement of balloon catheters in the lower uterine segment.

87. • The Atad Ripener
Device in place with the
two balloons inflated.
The uterine balloon is
at the internal os and
the cervicovaginal balloon
is at the external os.

88. • EXTRA-AMNIOTIC SALINE INFUSION
• Infusion of isotonic fluid into the extraovular space has been employed as an
adjunct to transcervical balloon catheter placement in the lower uterine
segment.
• The hypothesis – FERGUSON REFLEX
• Most commonly, isotonic saline is used; hence, the name extra-amniotic saline
infusion (EASI) and is infused continuously at rates of 20 to 40 ml/h.
• Cochrane review comparing EASI to any prostaglandin for cervical ripening
showed that EASI infusion was significantly less likely to result in vaginal delivery
within 24 hours, had a higher risk of cesarean delivery and did not reduce the
risk of hyperstimulation.
• From these data, there is little support for the use of EASI as an adjunct to
transcervical balloon catheter placement.

89. WHO
• Recommendations
1. Balloon catheter is recommended for induction of labour. (moderate-quality
evidence. strong recommendation.)
2. The combination of balloon catheter plus oxytocin is recommended as an
alternative method when prostaglandins (including misoprostol) are not available
or are contraindicated. (low-quality evidence. Weak recommendation.)
• Remark
1. The participants in the technical consultation noted that when using the balloon
catheter for induction of labour it is important to monitor the woman and her fetus
closely once labour is established. They also noted that balloon catheter and vaginal
prostaglandins may have similar effectiveness. However, balloon catheter may be
preferred for women with scarred uterus, since it is less likely to be associated with
hyperstimulation of the uterus.

90. Hygroscopic dilators
• They absorb endocervical and local tissue fluids,
causing the device to expand within the
endocervix and provide mechanical pressure.
• These dilators are either natural osmotic dilators
(e.g., Laminaria japonicum) or synthetic osmotic
dilators (e.g., Lamicel- magnesium sulfate in
polyvinyl alcohol), Dilapan (polyacrilonitrile)
• Advantages:
1- Outpatient placement
2- No need for fetal monitoring
3- Easy placement & removal
4- Low cost

91. Risks :
• Maternal & fetal infection
• Bleeding
• Membrane rupture
• Placental separation

92. THANK YOU