Time, place & preparation• Time of induction: Preferably early morning• Place of induction: where facility forintervention and fetal monitoring is available• Preparation of Patient : Enema may be givento patients prior to induction
• Misoprostol (a prostaglandin E1 analogue) has several potentialadvantages: it is stable at room temperature, it is relativelyinexpensive and it can be given via several routes (oral, vaginal,sublingual, buccal). These properties make misoprostol an idealagent for induction of labour, particularly in settings where theuse of prostaglandin E2 is not possible owing to lack ofavailability, facilities for storage, or financial constraints.• Since the use of a powerful uterotonic such as misoprostol canlead to adverse maternal and perinatal effects, it is importantto review the effectiveness and the side-effects of misoprostoluse in cervical priming and induction of labour. This commentaryevaluates three Cochrane reviews that sought to determine theeffectiveness and safety of misoprostol administered orally (3),buccally (sublingually) (4), or vaginally (5) for third-trimestercervical ripening and induction of labour.
Membrane sweeping• Its possible only if thecervix has ripened to allowthe passage of one finger.• Insertion of a glovedfinger through the cervixand it’s rotation againstthe wall of the uterus.• Its strips off the chorionicmembrane from theunderlying deciduareleases PGS• Placenta previa should beexcluded, Accidentalamniotomy is adisadvantage.
Amniotomy• AROMstretching of the cervix & separationof the membranes release of Prostaglandins• Depends on the state of the cervix and stationof the presenting part• ADV:High success rate and chance to see theamniotic fluid• DIS: cannot be applied in an unfavourablecervix, possibility of cord prolapse
Prostaglandins• Chemistry:PG is a carboxylicacid synthetised fromarachidonic acid.• Source: menstrual fluid,endometrium, decidua andamniotic membraneTYPES• PGE1 -amnion• PGE2-amnion• PGF2-decidua and myometrium• PGI2-myometrium
Mechanism of action• It causes change in themyometrial cell membpermeablity and alterationin the membrane boundcalcium• It also sensitises themometrium to the oxytocin• PGE2 has its collagenolyticactivityalter the groundsubstance of cervixcxripening
How to give Misoprostol?• Dose of 25 micro gram every 4hrly to amaximum of 6 doses can be givenintravaginally• Dose of 50micro gram every 3hrs to amaximum of 6 doses can be given orally• Dose of 25micro gram every 2hrs canbe given orally• Other routes of administration:1.Buccal2.rectal3.sublingual
Oral Vs vaginal MisoprostolORAL• Less effectivewhen comparedto vaginal PG• Chance of fetaldistress is lessVAGINAL• More effective whencompared to oralroute• Chance of fetaldistress is more
Dinoprostone• Vaginal gel 0.5mg can be givenintracervically.• It can be repeated after 6 hrs for 3 – 4doses if required• Vaginal tab 3 mg can be given inthe posterior fornix followed by3mg after 6-8 hrs to a maximumdose of 6mg• Vaginal pessary releasingdinoprostone 10mg over 24hrs.Itis removed when cx ripening isadequate
Misoprostol Vs Dinoprostone• Cheap & costeffective• Stable at room temp• Easy to administer• Costly• Need refrigeration
Advantages Disadvantages• Misoprostol is Cheapand has long half life• It is stable at roomtemp• Induction-deliveryinterval is short• Failure of induction isless• Powerful oxytoxiceffect irrespectiveof gestation• Side eff: Vomiting,diarrhoea• Bronchospasm• Hyerstimulation ofuterus• Tachysystole• Fetal distress• Rupture uterus
Oxytocin• It’s a nanopeptidesynthetised in the supraoptic and paraventricularnuclei of the hypothalamus.• Half life of 3-4 mins andduration of action 20 mins• Oxytocin is used verycommonly to achieveinduction of labour.• The objective is to produceuterine contractions thateffectively produce cervicalchange and descent of thepresenting part.
Mode of Action1.It acts throgh the receptor and voltagegated calcium channelmyometrialcontraction2.It stimulates amniotic and decidual PGproductionPreparations• Available in ampoules containing 5IU/ml• Buccal tab containing 50IU/ml• Nasal solution containing 40units/mlRoutes of administration:• 1.I.V infusion• Intra muscular• Buccal tablets• Nasal spray
How to give?Maximum dose of oxytocin 5IU in 500ml offluid at the rate of 40drops /min
Oxytocin (syntocinon) should be usedwith extreme caution in multiparouswomen. Oxytocin (syntocinon) should not bestarted for six hours followingadministration of vaginal prostaglandins If a trial of labour is judged safethen Oxytocin may be used. Oxytocin should be used with cautionwith a previous uterine scar. Oxytocin should always be used inconjunction with the partogram once inestablished labour.FACTS
Advantages• Cheaper and effective• Easy titrableDisadv:.Needs refrigeration.Effectiveness less with:1. less Bishop score2.IUD3.lesser weeks ofpregnancy
Hazards of oxytocin• Uterine hyperstimulation:(Normal:3 contractions in 10 minseach lasting for 45secs)(>5 contractions in 10mins eachlasting for 1min)• Water intoxication:It due toanti diuretic action(30-40IU/ml).Manifested byhyponatremia,confusion,comaand CCF• Fetal distress• Uterine rupture• Hypotension
When to interrupt?• When there is hyperstimulation ofuterus• Fetal distress• Signs of water intoxication.(Occurswith the max dose of 100 IU in theinterval of less than 24hrs .clinicallyManifested after 24hrs)
Oxytocin Vs Misoprostol• Safe,cheap andeffective• Unstable at roomtemp• Easily titrable• Chance of fetaldistress is less• More effective nearterm• Less effective withless Bishop scoreand in IUD• Tablet form ischeap& effective• Stable at roomtemp,PGE1-unstable• Not titrable• Chance of fetaldistress is more• Effectiveirrespective ofgestation
Failed Induction Of Labor• If Amniotomy is stillimpossible after amaximum no. of doses ofProstaglandins have beengiven or• If the cervix remainsuneffaced and <3cmdilated after anAmniotomy has beenperformed &• Oxytocin has beenrunning for 6-8hrs withregular contractions• Possible Causes1. Placental Sulfatasedeficiency2. Lack of EssentialCytokines
CONCLUSIONduring Induction of Labor,B enefits should be weighed,R isks should be assessed,A lternatives should be considered,N ecessity of intervention adjudged&D ecision should be takenaccordinglyBUT,INJUDICIOUS USE of Labor Inducing agents shouldbe avoided