A Randomised Controlled Trial Comparing Transcervical Foleys Catheter With Oral V/S Vaginal Misoprostol In Pregnant Women At Term For Induction Of Labor

Induction of labor (IOL) implies stimulation of contractions before the spontaneous onset of labor, with or without ruptured membranes. It is an intervention designed for iatrogenic ripening of cervix and to initiate uterine contractions leading to progressive dilatation and effacement of cervix resulting into birth of the newborn. It is indicated only when the risks of continuing pregnancy outweigh the benefits to the mother and the fetus.

Methods of IOL presently in use include various mechanical, pharmacological or a combination of mechanical and pharmacological.

Mechanical methods include use of various agents such as transcervical folleys catheter(TCFC) inflated with various amounts of fluid, laminaria tents, synthetic osmotic dilators etc. TCFC is cheap, readily available and easy to use and moreover less painful alternative which affects changes on various components of the bishop score and does not cause overstimulation of the uterus and does not increase the risk of rupture or intrauterine infection and does not adversely affect the fetus and newborn. However its potential side effects include premature rupture of membranes, chorioamnionitis, bleeding, displacement of presenting part and futire risk of preterm bith.

Pharmacological methods of IOL include agents such as oxytocin, prostaglandins, relaxin, nitic oxide donors such as isosorbide mononitrate, mifepristone etc out of which prostaglandins are the most widely used agents which include various sub classes such as PGE1 ie. Misoprostol and PGE2 known commonly as dinoprostone which is being used as gel and tablet, has the advantage of being used intracervical or vaginally but is expensive and needs refrigeration. Misoprostol originally used as gastroprotective agent , has advantage of being cheap, stable at room temperature and easy to be administered by various routes i.e. vaginal, oral, sublingual or rectal  where the former two routes of administration are most commonly used .

Absorption by oral route is more rapid than vaginally administered misoprostol reaching peak serum concentrations within 30 min compared to one hour with vaginal route. Oral misoprostol is eliminated rapidly (2–3 h)  than vaginal (>=4 h). In 2014, a Cochrane review on the use of orally administered misoprostol for IOL suggested that vaginal misoprostol was less effective than oral misoprostol at achieving vaginal birth, with an increased risk of uterine tachysystole and CS with vaginal misoprostol

Nowadays, a combination approach using pharmacological and mechanical methods is followed for IOL. Whereas misoprostol is more effective in improving the scores of cervical length and consistency, TCFC is better at improving the cervical dilatation score at pre-induction cervical ripening; thus, both improve different parameters.Both oral and vaginal routes of misoprostol for IOL have its merits and demerits and its efficacy and safety as an adjunct with TCFC has not been widely studied. IOL may lead to longer lengths of stay, increased hospital costs and increased newborn and maternal morbidities. In order to mitigate these risks,  it is important to choose methods of IOL which are safe and efficacious in achieving a vaginal delivery.

Hence, we plan to compare TCFC with  oral vs vaginal misoprostol as an adjunct for IOL in pregnant women at term.