There are many reasons moms-to-be might be interested in or need induction of labor. Patients might have decided that they:
- Are tired of being pregnant (and have made it to at least 39 weeks).
- Want to avoid a certain delivery date, such as a holiday. Alternatively, some patients have determined that some dates are favorable and want to deliver their babies on those specific dates.
- Need to arrange delivery around a loved one’s schedule. We’ve had women ask to be induced so their parents can arrange travel from overseas to be with them or a partner can be furloughed from the military and attend the delivery.
If your pregnancy is uncomplicated, it is best to wait to go into natural or spontaneous labor. In some situations, induction will be necessary because a complication has arisen that warrants delivery, such as preeclampsia or going significantly past your due date.
Your cervix plays a big role in determining the success of induction of labor. During pregnancy, the cervix usually is firm and stiff enough to help hold the baby in the uterus. That’s a good thing for most of the pregnancy. But in the final days or weeks before delivery, the cervix starts to soften and open up. Basically, it’s getting ready for labor. When this happens, we say that the cervix is becoming “favorable.”
If your cervix is has already started the process of softening and dilating, any method for induction has about an equal chance of success. But what if your cervix isn’t ready? If your cervix is still closed and firm, it might need some help before induction of labor is started. Your doctor may use the words “unripe” or “unfavorable.” In our experience, many women and their families don’t understand this part of process. In the following segment, we’ll describe commonly used methods to ripen the cervix so you and your family know what to expect.
Types of induction
During cervical ripening, we can use various methods to start preparing the cervix for contractions.
1. Mechanical cervical ripening
To say that we are mechanically ripening the cervix means that we are forcibly dilating it. A Foley catheter is typically used to drain urine from the bladder. The tip of the catheter has a balloon, which holds about 2 TBSP of water. If we place the tip of the Foley into the cervix and inflate the balloon, the balloon will push the cervix open over time.
Protocols vary, and the bulb will either be left inside the cervix for at least 12 hours or until it falls out. The cervix can also be dilated just by an examination by your provider. The finger can gently dilate the cervix and separate the membranes from the uterine wall. This is called “membrane stripping.” It may be uncomfortable for the patient, but it can be effective.
2. Medical cervical ripening
Medications also can be given to help induce softening and dilatation of the cervix. Oral or vaginal suppository drugs, such as misoprostol and other prostaglandins, are also commonly used to ripen the cervix. These medications come in different formulations, and the type you receive typically depends on what your doctor is familiar with and what is available at your delivery hospital.
Misoprostol comes in tablets that can be given by mouth or placed directly against the cervix. The medicine will be absorbed and will start softening your cervix over time. After several hours and several doses, you might end up 2 or 3 cm dilated, and, if you’re lucky, perhaps in early labor.
Other common formulations of medical induction agents include endocervical gels and vaginal inserts. They are similarly safe and effective and tend to be well tolerated by most patients. However, all of these medications can sometimes trigger too much uterine activity. If your doctor is worried about this, she may choose a mechanical form of cervical ripening.
3. Combination methods
In some protocols for cervical ripening, the mechanical and the medical agents are used simultaneously. Some studies have shown that using both methods at the same time is safe and can achieve the same result in less time.
Other considerations in cervical ripening
Misoprostol and other prostaglandins are not used for cervical ripening in term pregnancies with a prior cesarean birth or other prior major uterine surgeries, such as extensive myomectomies. These patients face an increased risk for uterine rupture.
You may not need cervical ripening if your cervix is already dilated, or if you’ve had a vaginal delivery before. If you do require cervical ripening before your induction of labor, we want you to understand that it is just the first step to having your baby. During the process, you may sleep some of the time and feel frustrated that not a whole lot is happening. It can be slow-going and pretty boring. If you are a low-risk patient, you might be allowed to have a light meal through the process.
We understand that patients and families are in a hurry to get the new baby here! But be patient. At the end, we hope to have a cervix that is ready for labor.
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