A 29 year old pregnant female is undelivered at 43 weeks gestation. She agrees to undergo induction. All of the following are options for cervical ripening except:

Inducing agents include - Prostaglandin E2 preparations available as a vaginal/cervical gel (Prepidil) or vaginal inse (Cervidil). Misoprostol, a synthetic PGE1 analogue for preinduction cervical ripening. It can be administered the oral or vaginal route. Mechanical ripening of the cervix can be achieved with laminaria, which is a hygroscopic dilator that is placed in the cervical canal and absorbs water from the surrounding cervical tissue. Oxytocin is not considered a cervical ripening agent but a labor-inducing agent.