Reasons for Induction

Every woman needs to be considered as an individual about whether she needs induction. Common reasons for induction of labor include:

• Post-dates pregnancy (41 weeks)

• Pregnancy-induced hypertension or preeclampsia (high blood pressure in pregnancy)

• Gestational diabetes

• Prelabor rupture of membranes - your water breaking without contractions

• Intrauterine growth restriction - baby not growing well

There may be other reasons based on your own pregnancy and situation that might mean you need to be induced.

The Process of Induction

Every woman’s induction will look different depending on her body and the reason that she is being induced. Below are some common ways that a woman may be induced

Cervidil or Prostin Gel - Cervical Ripening

Cervidil and prostin gel are two medications that can help the body get ready for labor. They each contain a medicine called a prostaglandin (prost-ah-GLAHN-din) that your body normally produces in the early part of labor. These medicines are used to help get the cervix ready for labor and for further induction.

Getting the cervix ready in this way is called cervical ripening. The goal is to allow the cervix to become softer and start to gently dilate (open). For some women, this process is enough to start their contractions and allow labor to continue. For others, they will need to have further induction once the cervix is ‘ripe’ (see below).

Cervidil is a small piece of fabric that looks similar to a small, flat tampon with an extra long string. It contains a slow-release medication that sits by the cervix for 12-24 hours. Prostin gel is a gel that contains the same type of medication and coats the cervix.

If you are having a cervidil or prostin gel induction, it is very likely that you will need several doses to ripen the cervix. This takes place over 1-3 days. Each day, you will come to the Labor and Delivery ward, your cervix will be checked and we will record baby’s heartbeat for 20 minutes to check on baby’s health. Then, the cervidil or prostin gel will be inserted into the vagina. You and your baby will be monitored for an hour, instructed to walk around the hospital for an hour, and will have another check of baby’s heartbeat before going home. You will then come back at a specific time for reassessment, unless your labor starts sooner than that - your doctor and nurse will review those instructions with you.

Not all women are suitable candidates to have a cervidil or prostin gel induction. Reasons that you may not be able to have these medications include:

• Ruptured membranes

• Previous C-section

• Previous major uterine surgery

• Current cancer of the cervix

• Polyhydramnios (extra fluid in the uterus)

Misoprostol Induction

Misoprostol is also a prostaglandin (prost-ah-GLAHN-din) medication, like cervidil and prostin gel. Unlike those medications, this one is taken as a pill. This medicine can help both to ripen the cervix and to start contractions.

If you are receiving misoprostol, you will be staying on the maternity ward for most of your induction. When you arrive, your cervix will be checked and we will monitor baby’s heartbeat and any contractions you are having on the monitor for 20 minutes. You will then be given a dose of misoprostol to swallow with a glass of water. You will remain on the monitor for at least 30 minutes, and will stay on the monitor if your contractions start. The medication can then be given every 4 hours until your contractions start, or you have had 6 doses.

Foley Catheter Induction

A Foley catheter is a rubber tube with an inflatable bulb or balloon at the end. It is usually used to empty the bladder but is used differently for an induction. It is used to help the cervix begin to stretch and open, as well as to encourage your body to start releasing its own prostaglandin hormones from the uterus and membranes (similar to a membrane sweep - see Your Pregnancy Schedule for more discussion on this).

For induction with a Foley catheter, your doctor will use a speculum to locate your cervix. The deflated tube of the Foley catheter will be gently inserted through the open part of the cervix to sit between your membranes and the wall of the uterus. The balloon of the Foley catheter will then be filled with water (from the end of the catheter that sits outside the body) to keep it inside the cervix. It will be pulled back just enough to place some pressure on the inner part of your cervix (internal os).

The Foley catheter then stays in until the cervix is dilated enough for it to fall out - this might be when labor has started or when the cervix is ripened.

Oxytocin Induction

Oxytocin is the hormone that our bodies release during in labor to produce contractions. We can use it to induce labor, assist with progression of labor, and to treat or prevent post-partum bleeding.

When used for induction, oxytocin is given through an IV, starting at a slow rate and increasing gradually as needed to produce regular contractions. For this to be effective, it is important that cervix be ‘ripe’ - this allows the contractions to more easily dilate the cervix and move the baby down. If the cervix is not ripe, then the oxytocin can produce contractions with minimal dilation and a higher likelihood of complications for your or baby.

An oxytocin induction may be fast or slow depending how your body responds. Your doctor and nursing team will be monitoring you closely to ensure that your labor continues to progress appropriately.

Some women find the process of oxytocin induction very intense. Depending on the reason for your induction and the ripeness of your cervix, your doctor will discuss with you whether an epidural may be appropriate early in your induction process.

Risks of the Induction Process

All medical procedures carry some amount of risk. Your doctor will discuss with you the specific risks for you of induction versus continuing to wait for labor. The risks of ongoing pregnancy will depend on your specific reason for induction.

The common risks of induction include:

• Over-stimulation of the uterus - prostaglandins and oxytocin can sometimes cause the uterus to contract too strongly or too often

  • This can sometimes affect the blood flow through the placenta to your baby

  • Removing the prostaglandin or stopping the oxytocin usually resolve this issue

  • In the uncommon case that baby’s heartrate is abnormal after removing or stopping the medication, you may need an operative delivery (C-section)

• Prelabor rupture of membranes - this may change the timeline of your induction and the type of induction you have

• Need for C-section - women who undergo induction overall have a lower risk of needing a C-section

  • If you do need a C-section, it is more commonly related to the reason for the induction or in few cases to over-stimulation of the uterus

  • The C-section is more likely to be an emergency C-section if one is needed