A cervical balloon is a mechanical way of inducing your labour as it does not involve any medications.
This procedure is performed on the labour ward by the doctors and involves a soft rubber tube being inserted through the cervix. Once in position the doctor will then inflate two balloons inside the tube, one above the cervix and one below the cervix. The balloon rubs against and stretches the cervix causing it to produce a hormone called prostaglandin. The prostaglandin causes the cervix to become shorter and soften (ripening). This prepares the cervix for labour and allows your midwife or doctor to break your waters.
Once the balloon is in you will return to the ward overnight before going back to labour ward in the morning to have the balloon removed and your waters broken. You will usually be offered a balloon if there is a reason why you would benefit from not having the medications. For example, if you have had a previous caesarean birth to avoid putting any strain on your scar, or if you have had a reaction to the induction medications which has made you contract too much.