Induction of Labour | Medical Science Optional Notes for UPSC PDF Download

Methods used for cervical ripening/Induction/Augmentation are

• PGE2 (dinoprostone) Gel, administered in the cervical region at a dosage of 0.5 mg, can be repeated every 6 hours, allowing for a total of three doses.
• Another option is the insertion of Misoprostol (PGE1) in the posterior fornix, with a common dosage being 25 µg vaginally every 4 hours as required. The maximum allowable dose is 150 µg.
• Nitric Oxide Donors can be employed as part of the process.
• Artificial rupture of membranes, also known as Surgical Amniotomy, is another approach.

Mechanical techniques used in case of unfavorable cervix are

• The use of Laminaria tents, which are hygroscopic cervical dilators, involves their absorption of fluid from the surrounding tissue, causing expansion. This expansion exerts radial pressure on the cervix and induces the release of prostaglandins, leading to a rapid improvement in the Bishop's score.
• Another method is the utilization of a Transcervical Foley's catheter, commonly known as a Balloon catheter.
• Membrane sweeping, performed during an internal examination, entails the practitioner moving their finger around the cervix to stimulate and/or separate the membranes around the baby. This action induces the release of prostaglandins, contributing to the initiation of labor.

Oxytocin infusion/drip

• Oxytocin finds application in both labor induction and augmentation.
• Typically, a 1-mL ampule containing 10 units is diluted into 1000 mL of Ringer's Lactate (RL) and administered through an infusion pump.
• This dilution results in oxytocin concentrations of either 10 or 20 milliunits per milliliter (mU/mL), depending on the specific mixture used.

Infusion rate

The Parkland Hospital protocol calls for a starting dose of oxytocin at 6 mU/min and with 6- mU/min increases every 40 minutes, but it employs flexible dosing based on uterine tachysystole.

When to Stop

In general, oxytocin should be discontinued if the number of contractions persists with a frequency of more than five in a 10-minute period or more than seven in a 15-minute period or with a persistent nonreassuring fetal heart rate pattern.

Modified Bishop's score is a system used to evaluate the condition of cervix and station of presenting part as a prognostic index for successful induction of labour.
It is shown in the table:

Total score 13, favourable score 6-13, unfavourable score 0-5

Induction of Labour-Repeats

Q1: Methods of induction of labour. (1994) 

Q2: What are the methods recently used for induction of labour? What are the indications for termination of induction of labour? (2013)