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Dr. Mona Shroff MD
INDUCTION OF LABOUR
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Dr Mona Shroff
DEFINITION
Artificial stimulation of uterine contractions before
spontaneous onset of labour with the purpose of
accomplishing successful vaginal delivery
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Dr Mona Shroff
INDICATIONS
MATERNALPreeclampsia,
eclampsiaPROMPostterm pregAbruptio placentaChorioamnionitisMedical
conditions-DM,Heart ds, Renal ds,Chr. HT etc
FETALIUFDFetal anomaly
incompatible with life
Severe IUGRRh
isoimmunisationMacrosomia
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Dr Mona Shroff
CONTRAINDICATIONS
Severe degree CPDMajor degree placenta praeviaTransverse liePrevious classical CS,MyomectomyPrevious>= 2 LSCSGrand multiparityActive genital herpesHypersensitivity to inducing agent
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RISKS OF INDUCTION
Failure leading to CSUterine hyperstimulationFetal distress,deathRupture uterusIntrauterine infection,sepsisIatrogenic delivery of preterm infantPrecipitate/dysfunctional labourInc. risk of operative vaginal deliveryInc. risk of birth traumaInc. risk of PPH
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Adverse Effects
Tachysystole Criteria: >10 contractions in 20 minutesDinoprostone Tachysystole Incidence: 33%Misoprostol Tachysystole Incidence
Intravaginal gel or tablet: 31 to 49%Oral crushed form or tablet: 16 to 22%
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Dr Mona Shroff
Hyperstimulation Criteria
Exaggerated uterine response (i.e. Tachysystole)Concerning Fetal Heart Rate tracing
Late Decelerations
Fetal Tachycardia >160 beats per minute
Dinoprostone Hyperstimulation Incidence: 17%Misoprostol Hyperstimulation Incidence
Intravaginal gel or tablet: 8%Oral crushed form or tablet: 1 to 2%
Uterine Rupture in VBAC Risk: 2.5% in Trial of Labor after Cesarean
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Dr Mona Shroff
PREREQUISITES
Establish indication clearlyInformed consentConformation of gestational ageAssessment of fetal size & presentationPelvic assessmentCervical assessment (BISHOPs score)Availability of trained personnel
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Dr Mona Shroff
MOD. BISHOPS SCORE
SCORE 0 1 2 3DILATATION 0 1-2 3-4 >4
EFFACEMENT 0-30% 40-50% 60-70% >80%
STATION -3 -2 -1/0 +1,+2,+3
CONSISTENCY firm medium soft
POSITION posterior
mid anterior
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Dr Mona Shroff
METHODS OF INDUCTION
NATURALBreast/nipple stimulationSexual intercourseMembrane strippingAmniotomyAcupuncture/acupressure
MECHANICALBalloon cathetersLamineria tentsSynthetic osmotic dilators
CHEMICAL
NONHORMONALHerbs,evening primrose oilHomeopathic prepEnemasCastor oil
HORMONALOxytocinProstaglandins –
PGE2,MisoprostolRelaxinNitric oxide donorsmifepristone
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Dr Mona Shroff
Stripping of the Membranes
Stripping of the membranes causes an increase in the activity of phospholipase and prostaglandin as well as causing mechanical dilation of the cervix, which releases prostaglandins. The membranes are stripped by inserting the examining finger through the internal cervical os and moving it in a circular direction to detach the inferior pole of the membranes from the lower uterine segment. [Evidence level C]
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contd.
Risks of this technique include infection, bleeding, accidental rupture of the membranes, and patient discomfort. The Cochrane reviewers concluded that stripping of the membranes alone does not seem to produce clinically important benefits, but when used as an adjunct does seem to be associated with a lower mean dose of oxytocin needed and an increased rate of normal vaginal deliveries. [Evidence level A, RCT]
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Dr Mona Shroff
Amniotomy.
It is hypothesized that amniotomy increases the production of, or causes a release of, prostaglandins locally. Risks associated with this procedure include umbilical cord prolapse or compression, maternal or neonatal infection, FHR deceleration, bleeding from placenta previa or low-lying placenta, and possible fetal injury.
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Dr Mona Shroff
Balloon catheters
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.
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Dr Mona Shroff
Prostaglandins
M/A :Act on the cervix to enable ripening by a number of different mechanisms. They alter the extracellular ground substance of the cervix, and PG increases the activity of collagenase in the cervix. They cause an increase in elastase, glycosaminoglycan, dermatan sulfate, and hyaluronic acid levels in the cervix. A relaxation of cervical smooth muscle facilitates dilation. prostaglandins allow for an increase in intracellular calcium levels, causing contraction of myometrial muscle..
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Dr Mona Shroff
contd.
Risks associated with the use of prostaglandins include uterine hyperstimulation and maternal side effects such as nausea, vomiting, diarrhea, and fever. Currently, two prostaglandin analogs are available for the purpose of cervical ripening, dinoprostone gel (CERVIPRIME: 0.5 mg ) and dinoprostone inserts (PRIMIPROST :10 mg ).
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Dr Mona Shroff
Technique for Placement of Dinoprostone Gel
Patient selection: Patient is afebrile. No active vaginal bleeding is present. Fetal heart rate tracing is reassuring. Patient gives informed consent. Bishop score is < 4. Bring gel to room temperature before application, per manufacturer's instructions.
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Dr Mona Shroff
Initiate Fetal Heart Rate and tocometry Start 15-30 minutes before gel insertedContinue monitoring for 30-120 minutes after
Insertion Technique Use one syringe of gel (0.5 mg )Introduce gel into cervix
Just below level of internal osIntracervical is preferred over posterior fornix (if leaking p/v posterior Fx)
Patient remains supine for 30 minutes
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Dr Mona Shroff
Dosing Repeat every 6 hours up to 3 doses in 24 hours
End points Bishop Score of 8 or greaterStrong uterine contractions
Drug interactions Wait 6-12 hours before starting Pitocin
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Dr Mona Shroff
PGE2 GEL