How can labor be induced?

Toward the end of their pregnancy, many expectant mothers can hardly wait for things to finally “get going” – especially if their baby's due date has passed. Some then try out various things themselves, like going on long walks. Having sex or stimulating their own nipples is believed to induce labor, too. The idea is that the hormones released when a woman is sexually aroused soften the cervix and help it to start opening (dilate). The hormones in sperm are also thought to have this effect. But research has not clearly shown that sexual activity can make the birth start sooner.

Some pregnant women drink raspberry leaf tea to soften the cervix, while others try homeopathy, evening primrose oil, clove oil tampons, or hypnosis. There's no scientific proof that these approaches work, though.

Some women try to start their contractions with the help of acupuncture. But there's no scientific proof that this works, either. Research in this area found that the time it took to give birth was similar – no matter whether the women were given acupuncture, sham acupuncture or no acupuncture at all. Sham acupuncture is when the needles are inserted in random places or not deep enough into the skin, for example.

For a long time, castor oil was traditionally used to induce labor. Known for its laxative effect, it comes in the form of pure oil, a "cocktail" (mixed with juice), or capsules that can be swallowed. Castor oil can cause nausea. There's not enough research to say whether it's a safe and effective way to induce labor.

Please note that some of the following information describes the situation in Germany specifically. You may find that things are different in other countries.

When a baby is more than a week past its due date, induction can lower the health risks for the mother and baby. This is because problems are slightly more likely from the 42^nd week onward. For example, it’s more common for these babies to need treatment in an intensive care unit when they’re born.

There are other reasons for inducing labor, too. One is if your water breaks too early and your contractions don’t start naturally in the next 24 hours. Another is if you have high blood pressure. This could be due to pre-eclampsia. Labor may also be induced if your baby is expected to be larger than average. Then an earlier birth could be easier for both you and your child. Your doctor or midwife might recommend inducing your labor for other health reasons – or at least give you the option.

Some women want to be induced before the 42^nd week of their pregnancy even though they don’t have any special health problems. If this is something you’re considering, it’s important to carefully consider the pros and cons together with your doctor or midwife. In Germany, this kind of induction is possible from the 40^th week onward.

The aim of labor induction is to get the cervix to dilate (open). If the cervix has already dilated, the aim is to make the contractions start.

During pregnancy, the cervix is usually closed tight to keep the baby safely in the womb. When your body starts preparing for birth, it releases hormones (prostaglandins) to make your cervix soften and dilate. A cervix that is ready for birth is called a “ripe” cervix. If this doesn’t happen by itself, mechanical approaches can be used to encourage the body to release the hormones. There are also medications that can help the cervix to soften and the contractions to begin.

The approach used will depend on things like how dilated your cervix is and whether your water has broken. It will also depend on whether this is your first baby or whether you’ve had a C-section or other womb surgery in the past.

Medically induced labor tends to be done in hospital, with the help of a childbirth team (a doctor and midwife). They keep an eye on you and your baby. That includes monitoring the baby’s heartbeat and your contractions. Sometimes, labor can be induced as an outpatient process. Then you can go home to wait for some time after you’ve been induced.

Various medications can be used to soften the cervix. They contain the hormone dinoprostone, which is a prostaglandin.

You can get this medication in the form of a vaginal suppository (tablet) or a gel to put inside your vagina. Alternatively, it can be used in the form of a vaginal insert (also known as a pessary). This looks a bit like a small tampon and it stays in your vagina for up to one day. Before you’re given one of these products, the doctor will examine the opening of your cervix. Then they will insert the product.

Sometimes the effect of these products isn't strong enough to get the contractions going properly on their own. Then you can be given extra medication after a certain amount of time – through a drip, for example.

Tablets containing misoprostol can also be used to induce labor. Misoprostol works in a similar way to prostaglandins. It helps to open the cervix and causes contractions. But you can only use it if you haven’t started having regular or painful contractions yet.

You take the tablet in hospital. The childbirth team keep an eye on you during the induction process. They check whether you and your baby are doing well and whether your contractions have started. If necessary, you can take another tablet a few hours later.

Sometimes the cervix is soft and open, but the contractions don’t start or they’re too weak. Then an oxytocin drip can help. The medication is delivered into a vein in your arm. It makes the muscles in the womb tighten and squeeze, causing contractions. This effect usually kicks in within just a few minutes. Oxytocin drips can also be combined with a procedure to artificially break your water (open the amniotic sac).

Labor-inducing medication can cause digestive problems like nausea, vomiting and diarrhea. Other potential side effects include fever and shivering.

Your childbirth team will choose a dose that makes the contractions as normal as possible. But sometimes labor-inducing medication causes contractions that are too strong and too frequent. The medical name for this is uterine hyperstimulation. If this happens, you might need extra medication to reduce the contractions and the pain. Having contractions that are too strong and too frequent can be stressful for your baby too.

If the contractions are particularly strong, the wall of the womb might tear open (uterine rupture). This is a medical emergency because it can cause heavy bleeding and the baby might not get enough oxygen. If the womb tears, the medical team usually delivers the baby by C-section as quickly as possible, and then they sew up the tear after that. Research suggests that the womb may tear in up to 4 out of 1,000 medication-induced births.

The risk of a uterine rupture is slightly higher if you’ve had a C-section or other womb surgery in the past. Then your doctor will talk to you beforehand about whether labor can be induced in your case and, if so, which approach is suitable.

One mechanical approach to inducing labor is called a membrane sweep. Here, the membranes of the amniotic sac surrounding the baby are separated from the wall of the womb. The doctor or midwife does this by inserting one or two fingers into your cervix and “sweeping” them around the lower part of your womb. It is also called membrane stripping or a cervical sweep.

Membrane sweeping causes the body to release hormones that help the contractions to start (prostaglandins). It can be done several times if necessary. Research suggests that two sweeps in the space of one week are more likely to start labor than just one sweep. Women who have two sweeps are also less likely to need further labor-inducing measures.

Most women find the procedure uncomfortable. It can cause bleeding, but this is usually not harmful.

A balloon catheter is a thin tube with one or two small balloons at the end of it. The doctor inserts the tube through the vagina into your cervix. Then the balloons are filled with a liquid to make them bigger. As a result, the balloon catheter presses against the inside of your cervix. This causes your body to release hormones (prostaglandins) that make your cervix soften and help the contractions to start. The balloon catheter stays in your cervix for around twelve hours. Some women find the process of inserting it unpleasant.

Like labor-inducing medication, balloon catheters can cause uterine hyperstimulation (contractions that are too strong and too frequent). The likelihood of this happening with balloon catheters is about the same as with misoprostol, but lower than with dinoprostone.

If the catheter isn’t enough to induce labor, you can also take labor-inducing medication to help things along.

Osmotic dilators (also called hygroscopic dilators) are thin rods that are inserted into the cervix. There, they absorb moisture and expand. This causes them to press against the inside of the cervix, like balloon catheters do.

If the cervix is already dilated, the doctor can artificially break your water (open the amniotic sac surrounding your baby). They do this using an instrument that looks a little like a crochet needle, which they insert through the vagina into the cervix. They then use the needle to burst the amniotic sac, and the fluid inside the sac comes out. This doesn't hurt. The aim is to make the contractions start.

Once the amniotic sac has been opened, your baby is no longer protected by the amniotic fluid. This means that bacteria can get into your womb. Because of this, you'll usually be given an oxytocin drip to speed up the birth as well.

After your water has broken, there's a risk of umbilical cord prolapse. This is when part of the umbilical cord slips past the baby into your vagina and gets squashed by the baby’s head or body. That can cut off the baby's blood and oxygen supply. If that happens, the medical team will deliver the baby quickly by C-section.

Women generally have very different experiences of induced labor. While some say they would do it again, others would rather avoid it if they have another baby.

Inducing labor doesn't necessarily mean that everything will happen really quickly. Many women are surprised how long it still takes for their baby to arrive. When labor is induced, more vaginal examinations are needed than usual. These examinations can be uncomfortable. If you’re connected to a CTG machine to monitor the baby’s heartbeat and your contractions, the wires may stop you from moving around freely.

It can be helpful to ask your midwife or doctor about how labor can be induced in your hospital, and about the pros and cons of each approach. Induction of labor isn't an emergency – there's usually enough time to get used to the idea and have all your questions answered.