Cervical Ripening

1. What is cervical ripening?

For labor to be successful, the cervix needs to be softened and thinned and the baby’s head descended into the birth canal with it’s head against the cervix. This softening and thinning of the cervix is called prodromal labor. Sometimes physicians try to increase the chances of a woman going into active labor with the use of prostaglandins. Normally, when your baby is ready to be born, your body produces prostaglandins to soften and thin the cervix. However, with inductions, your body may not ready to deliver your baby, so this cervical softening and thinning hasn’t occured. With inductions, prostaglandins may be given to start prodromal labor. This is called cervical ripening.

2. What are prostaglandins?

Prostaglandins are hormone-like substances which are involved in many bodily functions. In pregnant women, they are the active element in producing prodromal labor, which is the preparation for active labor.

There are a variety of prostaglandin compounds available for cervical ripening. The two approved for use in cervical ripening are very expensive, as is often the case with approved medications. Misoprostol, which is approved for heartburn, can also be used. The use of misoprostol in cervical ripening is what is called “off label.” It works, it’s safe, and much cheaper than the approved medications. The standard dose of misoprostol is 25 mg inserted vaginally. However, sometimes a second and third dose is given because the misoprostol doesn’t seem to be working well. If a second and third dose are given when the first one doesn’t produce the desired result, it can cause too many contractions which are too strong. 

3. How should misoprostol be used in cervical ripening?

When I administered misoprostol in my office, I would have my patients come to my clinic in the morning. We had special small induction rooms which were quiet and private. When the patient arrived at my clinic, I would do a non-stress test on the baby to establish the baseline fetal heart rate and I would then insert 25 mcg of misoprostol vaginally. I could easily check on my patients as I passed their rooms in my clinic. 

I monitored the mother the entire day and sent her home or to the hospital after the clinic closed. If my patients had gone home after they left the clinic instead of to the hospital, many would call me during dinner time and report they were ready to go to the hospital. I had many deliveries between 7:00 and 10:00 p.m. with my use of misoprostol. 

The secret to the success of my approach was to be patient and not give a second dose of misoprostol. Wait for the medication to work. Sometimes the misoprostol is crushed and put under the mother’s tongue, but in my experience this does not work. In my review of the studies of the use of misoprostol for cervical ripening, there were reports of hyperstimulation, but I suspect it’s the overdosing that causes the hyperstimulation.

The important message here is that if 25 mcg of misoprostol doesn’t start prodromal labor, your baby is not ready to be born.