Labor and Delivery

Labor and delivery are the process by which a baby is born, from the body's preparations to when the baby and the placenta leave the womb.

The earliest stage of labor prepares the body for delivery. This is a period of hours or days when the uterus regularly contracts and the cervix gradually thins out (called "effacing") and opens (called "dilation") to allow the baby to pass through.

Once the cervix has opened completely, the woman can begin pushing to deliver the baby. When the baby and placenta come out through the vagina, it is known as a vaginal delivery.

When does labor usually start?

For most women, labor begins sometime between week 37 and week 42 of pregnancy. Labor that occurs before 37 weeks of pregnancy is considered premature, or preterm.

Just as pregnancy is different for every woman, the start of labor, the signs of labor, and the length of time it takes to go through labor vary from woman to woman and even from pregnancy to pregnancy.

Signs of Labor

The primary sign of labor is a series of contractions (tightening and relaxing of the uterus) that arrive regularly. Over time, they become stronger, last longer, and are more frequent. Some women may experience false labor, when contractions are weak or irregular or stop when the woman changes positions. Women who have regular contractions every 5 to 10 minutes for an hour should let their health care provider know.

It is important to discuss labor and signs of labor with a health care provider early in pregnancy, before labor begins. Some providers may want a woman to wait until she has multiple signs of labor or is in "active" labor before coming to the hospital or birthing center.

Other signs of labor include:

  • "Lightening." This term refers to when the fetus "drops," or moves lower in the uterus. This may happen several weeks or only a few hours before labor begins. Not all fetuses drop before birth. Lightening gets its name from the feeling of lightness or relief that some women experience when the fetus moves from the rib cage to the pelvic area. It allows some women to breathe more easily and more deeply and may provide relief from heartburn.
  • Increase in vaginal discharge. Called "show" or "the bloody show," the discharge can be clear, pink, or slightly bloody. This discharge occurs as the cervix begins to open (dilate) and can happen several days before labor or just as labor begins.

Labor contractions before 37 weeks of pregnancy are a sign of preterm labor. Women who notice regular, frequent contractions at any point in pregnancy should notify a provider or go to the hospital. Providers can check for changes in the cervix to see whether labor has begun. As needed, providers can also give women in preterm labor specialized care. Among women who experience preterm labor, only about 10% go on to give birth within a week.

Other signs of labor include:

  • Change in vaginal discharge
  • Pain or pressure around the front of the pelvis or the rectum
  • Low, dull backache
  • Cramps that feel like menstrual cramps, with or without diarrhea
  • A gush or trickle of fluid, which is a sign of water breaking

Sometimes, if the health of the mother or the fetus is at risk, a woman's health care provider will recommend inducing or causing labor using medically supervised methods, such as medication.

Unless earlier delivery is medically necessary or occurs on its own, waiting until at least 39 weeks before delivering gives mother and baby the best chance for healthy outcomes. During the last few weeks of pregnancy, the fetus's lungs, brain, and liver are still developing.

What is induction of labor?

Induction of labor refers to the use of medications or other methods to induce, or cause, labor. This practice is used to make contractions start so that delivery can occur.

When would a provider induce labor?

Induction is usually used only when a problem with the pregnancy risks the health of either the mother or the fetus or when the due date has passed.

Monitoring the Body's Preparation for Labor

Several weeks before labor begins, the cervix begins to soften (called "ripening"), thin out, and open to prepare for delivery. If the cervix is not ready, especially if labor has not started 2 weeks or more after the due date, a health care provider may recommend medication or other means to ripen the cervix before inducing labor.

Health care providers use a scoring system, called the Bishop score, to determine how ready the cervix is for labor. The scores range from 0 to 13. A score of less than 6 means that the cervix may need help to prepare for labor.

Preparing the Cervix for Labor

If the cervix is not ready for labor, a health care provider may suggest one of the following steps to ripen the cervix:

  • Stripping the membranes. The health care provider can separate the thin tissue of the amniotic sac, which contains the fetus, from the wall of the uterus. This process causes the body to release prostaglandins (pronounced pros-tuh-GLAN-dins), which soften the cervix and cause contractions.
  • Giving prostaglandins. This drug may be inserted into the vagina or given by mouth. The body naturally makes these chemicals to ripen the cervix, but sometimes additional amounts are needed to help labor occur.
  • Inserting a catheter. A small tube with an inflatable balloon on the end can be placed in the cervix to widen it.

How is labor induced?

Once the cervix is ripe, a health care provider may recommend one of the following techniques to start contractions or to make them stronger:

  • Amniotomy (pronounced am-nee-OT-uh-mee). A health care provider uses a tool to make a small hole in the amniotic sac, causing it to rupture (or the water to break) and contractions to start.
  • Giving oxytocin (also called Pitocin). Oxytocin is a hormone the body naturally makes that causes contractions. It is given to start labor or to speed up labor that has already begun.

Can induction be requested?

In most cases, induction is limited to situations in which there is a problem with the pregnancy or in which the pregnancy has continued past the infant's due date. It is usually best to "let the baby set the delivery date" and allow labor to begin on its own, unless there is a medical reason to do otherwise.

Women who want labor induction for non-medical reasons should discuss it with their health care providers.

What are the stages of labor?

Stage 1

The first stage of labor happens in two phases: early labor and active labor. Typically, it is the longest stage of the process.

During early labor:

  • The opening of the uterus, called the cervix, starts to thin and open wider, or dilate.
  • Contractions get stronger, last 30 to 60 seconds, and come every 5 to 20 minutes.
  • The woman may have a clear or slightly bloody discharge, called "show."

A woman may experience this phase for up to 20 hours, especially if she is giving birth for the first time.

During active labor:

  • Contractions become stronger, longer, and more painful.
  • Contractions come closer together, meaning that the woman may not have much time to relax in between.
  • The woman may feel pressure in her lower back.
  • The cervix starts dilating faster.
  • The fetus starts to move into the birth canal.

Stage 2

At this stage, the cervix reaches full dilation, meaning that it is as open as it needs to be for delivery (10 centimeters). The woman begins to push (or is sometimes told to "bear down") to help the baby move through the birth canal.

During stage 2:

  • The woman may feel pressure on her rectum as the baby's head moves through the vagina.
  • She may feel the urge to push, as if having a bowel movement.
  • The baby's head starts to show in the vaginal opening (called "crowning").
  • The health care provider guides the baby out of the vagina.

This stage can last between 20 minutes and several hours. It usually lasts longer for first-time mothers and for those who receive certain pain medications.

Stage 3

Once the baby comes out, the health care provider cuts the umbilical cord, which connected the mother and fetus during pregnancy. In stage 3, the placenta is delivered. The placenta is the organ that gave the fetus food and oxygen through the umbilical cord during the pregnancy. It separates from the wall of the uterus and also comes out the birth canal. The placenta may come out on its own, or its delivery may require a provider's help.

During stage 3:

  • Contractions begin 5 to 10 minutes after the baby is delivered.
  • The woman may have chills or feel shaky.

Typically, it takes less than 30 minutes for the placenta to exit the vagina. The health care provider may ask the woman to push. The provider might pull gently on the umbilical cord and massage the uterus to help the placenta come out. In some cases, the woman might receive medication to prevent bleeding.

What are the options for pain relief during labor and delivery?

The amount of pain felt during labor and delivery is different for every woman. The level of pain depends on many factors, including the size and position of the baby, the woman's level of comfort with the process, and the strength of her contractions.

There are two general ways to relieve pain during labor and delivery: using medications and using "natural" methods (no medications). Some women choose one way or another, while other women rely on a combination of the two.

A woman should discuss the many aspects of labor with her health care provider well before labor begins to ensure that she understands all of the options, risks, and benefits of pain relief during labor and delivery before making a decision. It might also be helpful to put all the decisions in writing to clarify things for all those who might be involved with delivering the baby.

Pain-Relieving Medications

Pain-relief drugs fall into two categories: analgesics (pronounced an-uhl-JEE-ziks) and anesthetics (pronounced an-uhs-THET-iks).

Each category has different forms of medications. Some of these medications carry risks. It is important for women to discuss medications with their health care provider before going into labor to ensure that they are making informed decisions about pain relief.

Analgesics

Analgesics relieve pain without causing total loss of feeling or muscle movement. These drugs do not always stop pain completely, but they reduce it.

  • Systemic analgesics affect the whole nervous system rather than a single area. They ease pain but do not cause the patient to go to sleep. Systemic analgesics are often used in early labor. They are not given right before delivery, because they may slow the baby's breathing and reflexes. They are given in three ways:
    • Injected into a muscle or vein
    • Administered through a small tube placed in a vein. The woman can often control the amount of analgesic flowing through the tube.
    • Inhaled or breathed in with a mixture of oxygen. The woman holds a mask to her face, so she decides how much or how little analgesic she receives for pain relief.
  • Regional analgesics relieve pain in one region of the body. In the United States, regional analgesia is the most common way to relieve pain during labor. Several types of regional analgesia can be given during labor:
    • Epidural analgesia, also called an epidural block or an epidural, causes loss of feeling in the lower body while the patient stays awake. The drug starts working about 10 minutes to 20 minutes after it is given. A health care provider injects the drug near the spinal cord. A small tube (catheter) is placed through the needle. The needle is then withdrawn, but the tube stays in place. Small amounts of the drug can then be given through the catheter throughout labor without the need for another injection.
    • A spinal block is an injection of a much smaller amount of the drug into the sac of spinal fluid around the spine. The drug starts working right away, but it lasts for only 1 to 2 hours. Usually, a spinal block is given only once during labor, to help with pain during delivery.
    • A combined spinal-epidural block, also called a "walking epidural," gives the benefits of an epidural block and a spinal block. The spinal part relieves pain immediately. The epidural part allows drugs to be given throughout labor. Some women may be able to walk around after a combined spinal-epidural block.

Anesthetics

Anesthetics block all feeling, including pain.

  • General anesthesia causes the patient to go to sleep. The patient does not feel pain while asleep.
  • Local anesthesia removes all feeling, including pain, from a small part of the body while the patient stays awake. It does not lessen the pain of contractions. Health care providers often use it when performing an episiotomy (pronounced uh-pee-zee-OT-uh-mee), a surgical cut made in the region between the vagina and anus to widen the vaginal opening for delivery or when repairing vaginal tears that happen during birth.

Natural Pain-Relief Methods (Also Called Natural Childbirth)

Women who choose natural childbirth rely on a number of ways to ease pain without taking medication. These include:

  • The company of others who offer reassurance, advice, or other help throughout labor, also known as continuous labor support
  • Relaxation techniques, such as deep breathing, music therapy, or biofeedback
  • A soothing atmosphere
  • Moving and changing positions frequently
  • Using a birthing ball
  • Massage
  • Yoga
  • Taking a bath or shower
  • Hypnosis
  • Using soothing scents (aromatherapy)
  • Acupuncture or acupressure
  • Applying small doses of electrical stimulation to nerve fibers to activate the body's own pain-relieving substances (called transcutaneous electrical nerve stimulation, or TENS)
  • Injecting sterile water into the lower back, which can relieve the intense discomfort and pain in the lower back known as back labor

What is a C-section?

A cesarean delivery, also called a C-section or cesarean birth, is the surgical delivery of a baby through a surgical cut or incision in a woman's abdomen and uterus. After the baby is removed from the womb, the uterus and abdomen are closed with stitches that later dissolve.

According to the U.S. Centers for Disease Control and Prevention, in 2015, 32% of births were by cesarean delivery—the lowest rate since 2007. Between 1996 and 2008, the number of cesarean deliveries increased by 72%.

 

What are some common complications during labor and delivery?

Each pregnancy and delivery is different, and problems may arise.

If complications occur, providers may assist by monitoring the situation closely and intervening, as necessary.

Some of the more common complications are:

  • Labor that does not progress. Sometimes contractions weaken, the cervix does not dilate enough or in a timely manner, or the infant's descent in the birth canal does not proceed smoothly. If labor is not progressing, a health care provider may give the woman medications to increase contractions and speed up labor, or the woman may need a cesarean delivery.
  • Perineal tears. A woman's vagina and the surrounding tissues are likely to tear during the delivery process. Sometimes these tears heal on their own. If a tear is more serious or the woman has had an episiotomy (a surgical cut between the vagina and anus), her provider will help repair the tear using stitches.
  • Problems with the umbilical cord. The umbilical cord may get caught on an arm or leg as the infant travels through the birth canal. Typically, a provider intervenes if the cord becomes wrapped around the infant's neck, is compressed, or comes out before the infant.
  • Abnormal heart rate of the baby. Many times, an abnormal heart rate during labor does not mean that there is a problem. A health care provider will likely ask the woman to switch positions to help the infant get more blood flow. In certain instances, such as when test results show a larger problem, delivery might have to happen right away. In this situation, the woman is more likely to need an emergency cesarean delivery, or the health care provider may need to do an episiotomy to widen the vaginal opening for delivery.
  • Water breaking early. Labor usually starts on its own within 24 hours of the woman's water breaking. If not, and if the pregnancy is at or near term, the provider will likely induce labor. If a pregnant woman's water breaks before 34 weeks of pregnancy, the woman will be monitored in the hospital. Infection can become a major concern if the woman's water breaks early and labor does not begin on its own.
  • Perinatal asphyxia. This condition occurs when the fetus does not get enough oxygen in the uterus or the infant does not get enough oxygen during labor or delivery or just after birth.
  • Shoulder dystocia. In this situation, the infant's head has come out of the vagina, but one of the shoulders becomes stuck.
  • Excessive bleeding. If delivery results in tears to the uterus, or if the uterus does not contract to deliver the placenta, heavy bleeding can result. Worldwide, such bleeding is a leading cause of maternal death. NICHD has supported studies to investigate the use of misoprostol to reduce bleeding, especially in resource-poor settings.

Delivery may also require a provider's special attention when the pregnancy lasts more than 42 weeks, when the woman had a C-section in a previous pregnancy, or when she is older than a certain age.

Source: National Institutes of Child Health and Human Development
Last updated : 6/3/2022

Labor and Delivery originally published by National Institutes of Child Health and Human Development