Labour Induction Methods: An Overview

Overall the rate of induced labours has increased and almost 25% of women undergo labour induction worldwide. Cervical ripening and cervical preparedness is necessary before labour can be induced. The status of the cervix is traditionally assessed with help of Bishop's score. Labour induction becomes necessary when the cervix is not favourable as noted on the cervical scoring system. Mechanical or surgical methods or a combination of both can be sued for labour induction. These include Foley's catheter induction, sweeping of membranes, amniotomy etc. Pharmacological agents like oxytocin, prostaglandins PGE1 & PGE2 and newer agents like mifepristone can be used. Mechanical methods like Foley's catheter induction are associated with lesser FHR variability and decreased rates of caesarean section as compared with oxytocin infusion or prostaglandins used locally. Oxytocin is the most widely used pharmacological method used for induction of labour. Proper titration of oxytocin can result in contractions that mimic normal labour. Oxytocin is often combined with amniotomy. Prostaglandins PGE1 & PGE2 are safe and effective options for labour induction. Prostaglandin PGE1 or misoprostol is used in the dose of 25 microgram mcg given orally or vaginally or via the sub-lingual route. Prostaglandin PGE2 or dinoprostone is used intra-cervically or vaginally in the posterior fornix. The newer drug mifepristone is being studied as cervical ripening agents because of its anti-progesterone effect.