Induction of labour Definition :- Induction of labour is defined as the artificial initiation of labour , performed when it is considered that there are benefits to the baby and or mother if the baby is delivered , compared with the alternative of the baby remaining in utero . Current rate of induction of labour are 20 - 22 % .
Indications 1-Abruptio placentae .2-Chorioamnionitis .3-fetal demise .4- Gestational hypertension .5- Pre-eclampsia and eclampsia .6- Pre-labour rupture of membranes .7- post term .8- Maternal medical conditions .9- fetal comprise .
Contraindications Absolute contraindications :-- Contraindication to vaginal delivery such as 1-complete placenta praevia 2-vasa praevia 3- transverse lie . 4-Conditions need immediate delivery such as cord prolapse 5-Previous classical C/S and previous myomectomy entering the endometrial cavity .
Relative contraindicationsPrevious C/S ( at increased risk of uterine rupture ). Success of induction of labor ::-- IOL is most successful when the cervix is ripe at the time of induction .
●Ripening :- is the process by which the cervix changes in consistency prior to the onset of labour , collagen content decline and water content increases . The most commonly used assessment of cervical ripening is the Bishop score . this score comprises five components of the cervix , all assessed on vaginal examination . IOL with unripe cervix will require more uterine activity to effect cervical dilatation , potentially causing , a longer labour , more pain and stress for both mother and baby , higher risk of uterine rupture and increase incidence of instrumental delivery and C/S .
Note :--- Bishop score of 8 and above mean high success rate of induction while low score mean unfavourable cervix and high failure rate of induction .
Pharmacological method 1-intravaginal prostaglandin (PG E2, dinoprostone) 2- intravaginal prostaglandin (PG E1, misoprostol ) Mechanical method :-- ( increase maternal infection ) 1-intrauterine administration of Foley catheter followed by extra amniotic saline . 2- laminaria . 3-Membrane sweeping . Once the cervix is ripe , continuation of labor induction may involve fore water amniotomy ( artificial rupture of membrane ) with or without augmentation of labor with Syntocinon .
Augmentation of labor :- is the process of speeding up the first stage of labor .Amniotomy with or without oxytocin has been the standard intervention . Complications 1--Failure of procedure , 15% in primigravida with unfavourable cervix but less commonly with multigravida and primi with favourable cervix and high Bishop score at the start of induction . 2--Caesarean section and operative delivery .
3-Hyperstimulation :- uterine hyperstimulation is defined as a contraction frequency of more than five in 10 min. or contraction exceeding 2 min. duration . 4-Tachysystol : occur when uterine hyperstimulation is accompanied by abnormal FHR patter n , which manage by Putting the patient in left lateral position , O2 mask , rehydration , and if FHR not improve finally we can give the patient tocolytic agent such as Teributalin .
Monitoring Monitoring of maternal and fetal wellbeing during induction of labor is sparse . cardiotocograph should be performed to confirm that the FHR is normal prior to PG insertion .The CTG should repeated when contraction begin , normally 2-6 hr after PG administration .