Pain Relief During Childbirth: A Comprehensive Review

Dr. Bhavani Shankar Kodali
Associate Professor
Harvard Medical School
Brigham and Women's Hospital
Boston, MA (USA)

Dr. Karl Frindrich
Fellow
Harvard Medical School
Brigham and Women's Hospital
Boston, MA (USA)

The methods of pain relief offered to expectant mothers have increased significantly since the first half of the 20th century. It is fortunate that in this era, pain relief during labor and delivery is an accepted part of the birthing process. The American College of Obstetricians and Gynecologists (ACOG), in their committee opinion # 118, summarizes pain relief during childbirth as follows: "Labor results in severe pain for many women. There is no other circumstance where it is considered acceptable for a person to experience severe pain, amenable to safe intervention, while under a physician's care. Maternal request is a sufficient justification for pain relief during labor." The following is a guide to both pharmacologic and nonpharmacologic methods of pain control for the practitioner with the goal of keeping women safe and comfortable during labor. It includes a brief description of available practices, opinion of said practices based on research available, and references to find more information on the administration of these different methods of pain control.

The first pain-free childbirth using regional anesthesia was reported in July of 1900. Since then, a firm and dedicated commitment of anesthesiologists and professional societies such as the Society of Obstetric Anesthesia and Perinatology (SOAP) in the last century have led to tremendous advances in regional anesthesia. This has led to the availability of safe pain-free delivery to requesting expectant mothers. More than 2 million mothers used epidural analgesia to deliver their babies in the year 2000. Over 70% of pregnant women at Brigham & Womens Hospital, Boston choose epidural analgesia for childbirth. In the United States, national average use of epidural analgesia in the year 1992 was about 51%. The American College of Obstetricians and Gynecologists (ACOG) also believes that "of the various pharmacological methods used for pain relief during labor and delivery, the lumbar epidural block is the most effective and least depressant, allowing for an alert, participating mother."

Physiology of Labor Pain:

Each woman's labor is unique. The amount of pain is experienced is dependent on many different factors, which include:

  • Size of the baby
  • Position of the baby
  • Dimensions of the pelvis
  • Strength of the contraction
  • Mother's previous experience and expectations
  • Many issues not yet understood

For details visit: www.brighamandwomens.org/painfreebirthing/painofchildbirth.asp

Methods of Pain Relief:

1. Non-pharmacologic Methods of Pain Relief (Non- Medicated):

There are instances where a mother may wish not to use medications or regional anesthesia for childbirth or these options may not be available in some parts of the world. In these situations there are methods available that have been found by many laboring mothers to assist in dealing with the pain of labor. Included is a short description of each method and a link for more detailed information on the subject. In an effort to provide views based on good research we have summarized information on the following methods of nonpharmacologic pain relief.

It is hard to predict how much pain mothers will have until they go through labor. Some women have tolerable, controllable levels of pain, while others may benefit from some form of pain relief. Many non-medical techniques exist that can help with pain during labor, including breathing/ relaxation techniques, warm showers, massage, supportive nursing care, position changes (standing, sitting, walking, rocking), and using a labor ball to name a few.

  • Hypnobirthing®
    Hypnobirthing was introduced in the 19th century utilizing techniques for fear release and relaxation. "Women attempt to relieve all anxiety and reach a loose, limp, rag doll relaxed state.... then the body can do what it was designed to do during birth, without constriction and resulting discomfort"

    For details visit: www.painfreebirthing.com/hypnotherapy.htm or www.hypnobirthing.com

  • Lamaze
    Lamaze is another technique used by some women. Dr. Grantley Dick Read encouraged women to give birth naturally by reducing the fear (and pain) of childbirth through knowledge and relaxation. Dr. Lamaze advanced a number of simple strategies to facilitate normal birth and help women to give birth without medication. Psychoprohylaxis, the Lamaze Method of Childbirth, consists of continuous labor support (by the monitrice) and the use of a repertoire of relaxation and breathing strategies. Lamaze believed that controlled, conditioned breathing exercises were effective in blocking women's perception of pain of contractions.

    For details visit: www.painfreebirthing.com/lamaze.htm or www.lamaze-childbirth.com

  • Bathing
    Many laboring women find bathing decreases the pain of labor. They have used baths for years in out-of-hospital birth settings for both labor and birth. Many hospitals either provide a bath service or allow families to bring in bathing equipment.

    For details visit: www.painfreebirthing.com/bathing.htm

  • Acupuncture
    Acupuncture has been used for thousands of years to assist with pain control, addiction, nausea/vomiting and many other purported uses. There have not been very many good studies to date of the effectiveness of acupuncture regarding pain control in labor. In theory there are more than 365 points along the 12 'meridians' (energy paths) of the body. Interruptions of energy flow (surgery, labor etc.) along meridians breaks up the harmony of the body producing feelings of pain or uneasiness.

    For details visit: www.painfreebirthing.com/acupuncture.htm

  • TENS
    TENS is the application of a very small electrical current to the skin to decrease the perception of pain elsewhere in the body. TENS has been used for surgical and chronic pain patients. The current prevents pain signals from reaching the brain, just like a gate not letting anything pass. In theory this may stimulates the body's production of higher levels of endorphins (natural painkillers).

    For details visit: www.painfreebirthing.com/tens.htm

  • Cutaneous Sterile Water Injections
    Many studies report 30-70% of laboring women have significant lower back pain. This has been thought to be in part due to the occiput posterior position of many babies in the mother's birth canal. Injections of small amount of sterile water just beneath the skin at the lower back have been reported to decrease this back pain. The mechanism is thought to be pain relief through distraction or a release of endorphins (natural painkillers) much like acupuncture. This may also be helpful for women who wish to delay epidural placement or relieve pain early in labor.

2. Pharmacologic Methods (Medicated methods of childbirth pain relief):

  • Intravenous Medications
    There are medications available that are given intravenously or intramuscularly to decrease the amount of labor pain. These medications are usually ordered by the obstetricians /midwives, and often given by nurses. Opioids are the most effective medications for the relief of pain. They have a long history of use in obstetrics for the relief of the labor and delivery pain. Although there are a great number of narcotics available today, only a few are commonly used for childbirth: meperidine (Demerol), morphine, fentanyl, butorphanol (Stadol), and nalbuphine (Nubain). These medications do not normally provide complete analgesia. The amount of pain relief does vary, but they can take the "edge" off the pain and make labor more tolerable. The vast majority of women who do not have a regional anesthetic for labor do opt for one of these medications. There is no problem with receiving such medications prior to receiving an epidural or spinal anesthetic.

    If the medications ordered by the obstetrician are not enough to provide satisfactory pain relief, the anesthesiologist can arrange administration of medications via an intravenous infusion pump. Here, women are provided with a button that can be activated whenever they desire pain relief. The pump is programmed deliver a set amount of medication into your system and is called 'patient controlled analgesia' (PCA). Women can control the delivered amount of pain medication up to a determined safety point. The anesthesiologist and nurse will monitor the intravenous medications being administered.

    A major disadvantage of IV medications is that these medications make laboring women drowsy and sleepy. In addition, there may be other side effects including nausea, vomiting, decreased respiratory rate, itching, constipation and urinary retention. If women are planning to breast feed, initial efforts may be difficult.

    Effect on the baby:
    Another side effect of narcotics is, they all cross the placenta and enter the baby's circulation. As a result of this, the baby may also show some effects. In utero, the baby's heart rate may change slightly in pattern. There are no deleterious effects known due to this change in heart rate pattern.

    The baby has the ability to metabolize the medications, but it does so more slowly than the mother. After delivery the baby may be slightly sleepy. Again, it is unlikely that the baby will be affected adversely as a result of small amounts of pain medications, but it is important to realize that the medication is getting to the baby. The probability of seeing an effect of mother's medication in the baby may be dependent on the dosing of medication in relation to the time of birth. If the baby has adequate time to break down the medication, only a minimal effect may be seen. Most practitioners feel that it is safe for the baby when narcotics are given to mother to relieve labor pain.

    For details visit: www.brighamandwomens.org/painfreebirthing/systemic.asp

  • Regional Anesthesia
    There are different aspects of pain felt by the mother at different periods in labor. The first part of labor with uterine contraction and cervical dilation produces more visceral non-localized pain transmitted from spinal segments T10-L1 to the brain. A frequent complaint in stage one labor is lower back pain often associated with an occiput posterior fetal position. The second stage of labor from complete cervical dilation to delivery of the baby produces more somatic localized pain transmitted by spinal segments S2-4 to the brain. The goal of regional anesthesia is to administer medications directly to the CSF (cerebro spinal fluid) or surrounding nerves to inhibit transfer of these pain impulses while allowing the mother to maintain lower extremity motor and pushing ability.

    For details visit: www.painfreebirthing.com/methods2.htm

    Types of regional anesthesia for labor and vaginal delivery:

    1. Epidural
    2. Combined spinal epidural (CSE)

    Epidural:
    Epidural is medication delivered through a small flexible catheter placed in the epidural space at the L3-4 interspace and taped to the back. Medications administered by epidural include bupivicain, ropivicain along with fentanyl. These medications are delivered at a constant rate by a pump or administered in bolus dose as needed. Epidural anesthetics allow woman to remain awake and alert but more comfortable during contractions of childbirth. Different medications and combinations of medications for epidural anesthesia are used at different institutions.

    For details: www.painfreebirthing.com/epidproc.htm

What happens after epidural placement?

Continual Vigilance

After epidural placement, the patient will be under the watchful eyes of the labor and delivery nurse and the anesthesiologist. There will be continuous monitoring of baby's heart rate. Vital signs will be recorded frequently. Frequency of uterine contractions is also recorded. Although one is resting, or sleeping while labor progresses, the monitoring and vigilance continues unimpeded.

Do epidurals affect blood pressure?

The nurse and the anesthesiologist will monitor blood pressure all through epidural anesthesia. Occasionally, the blood pressure can decrease during epidural anesthesia. The anesthesiologist will correct the decreases expeditiously with I.V medications to normalize the blood pressure. This transient decreases in blood pressure should pose no problem for the baby, as baby is under constant surveillance via fetal heart rate monitor.

Goal of the ideal epidural anesthesia
Anesthesiologists aim to provide good pain relief without impeding ones ability to move legs or push the baby out during childbirth. In other words, the patient will be pain free but will be able to move legs during epidural analgesia. A relatively new development is 'walking epidural' (see section on "Walking epidural"), which allows the patient to stand up and walk during labor. Although one may feel strong enough to stand up and move around, some hospital policies may not allow to walk once epidural is in place.

Depending upon one's requirements for local anesthetic medications via epidural, occasionally one can have transient weakness of legs hampering ability to move legs, which should resolve over time. The anesthesiologist with the assistance of labor and delivery nurse would monitor requirements of local anesthetic medications via epidural route.

Combined Spinal Epidural (CSE):
Often in multiparous women or mothers late in labor we find it beneficial to place a combined spinal epidural to provide more immediate pain relief for rapid or late laboring women. This technique is identical to epidural placement with the following exceptions. Once the epidural space is located by needle. A second needle administers a local anesthetic with narcotic into the intrathecal space through the epidural finder needle. The epidural catheter is then placed as usual and the epidural pump is started. Benefits of the CSE include immediate pain relief with near full strength of abdominal and limb muscles.

Combined spinal epidural techniques (CSE) can combine the advantages of each technique. Distinct advantages of CSE over the epidural are:

  • Rapid onset
  • Profound suppression of pain
  • Minimal loss of ability to move legs
  • Negligible amount of medications going to other systems of the body, including the baby
  • High satisfaction rate from the expectant mother

For details: www.brighamandwomens.org/painfreebirthing/cse.asp

Frequently asked questions:

How does pain relief affect labor?

Epidural analgesia minimally lengthens labor and does not increase the risk of cesarean delivery

  • Patients receiving epidural analgesia have longer labors when compared to women receiving I.V method of childbirth pain relief. Numerous studies have shown that the difference is approximately one hour on an average. However, this may be highly variable depending on your labor pattern.
  • Epidural analgesia does not increase the risk of cesarean delivery. Randomized clinical trials present powerful evidence that there is no added risk of cesarean delivery owing to epidural analgesia.
  • The relationship between epidural analgesia and forceps deliveries is complex. Some studies have shown more forceps deliveries in patients with epidurals while others have not. This may be highly dependent on practice style and preferences of your own obstetrician.
  • Patient satisfaction and neonatal outcome are better after epidural than I.V method of childbirth pain relief.

If you would like to know more details, click below:

DETAILS

When is the optimum time to administer an epidural, CSE, or spinal during childbirth?

The decision to receive an epidural anesthetic is between you, your obstetrician/midwife, and your anesthesiologist. Epidural analgesia is generally given when you have begun active labor with regular painful uterine contractions. We recommend that if you are even minimally interested in getting an epidural, you ask to see the anesthesiologist in advance. This will allow the anesthesiologist to obtain your complete medical history and to perform a physical exam. Most importantly, you can discuss your pain relief options before you are in severe pain. Telling the anesthesiologist your preference, or signing a consent form for anesthesia does NOT obligate you to get an epidural anesthetic. You may later decide that you would rather have natural childbirth or another method of pain relief.
Many factors determine when you can get an epidural, including the position of the baby in the birth canal, or whether this is your first baby or a later child. Some obstetricians/midwives would prefer that you be dilated at least four centimeters prior to getting an epidural. These obstetricians/midwives believe that an early epidural may slow your labor, but the available data on this topic is controversial. Certain medical conditions, however, may favor earlier commencement of epidural analgesia. Once the obstetrician/midwife gives his/her permission for you to get an epidural anesthetic, the anesthesiologist will place the epidural. If you have not seen an anesthesiologist in advance, an abbreviated history and physical, and consent for the procedure will be obtained.

It is almost never too late to get an epidural unless the head of the baby is visible (crowning). Even if you initially attempted natural childbirth and never saw an anesthesiologist, you may change your mind later on if you find labor to be extremely painful. It is our recommendation that you attend childbirth education classes and listen to a lecture about the available forms of pain relief. It is important that you keep an open mind and be flexible throughout the prenatal period and labor itself. Different people experience labor differently, and being flexible provides the maximum benefit for you and your baby.

Recent opinion of American college of Obstetricians and Gynecologists: Issue date, February 2002:
Various studies report conflicting data with regard to the level of risk of cesarean delivery for nulliparous women (women with first pregnancy) who receive epidural analgesia before 5 cm of cervical dilatation. As a result some institutions are requiring that laboring women reach 4-5 cm of dilatation before receiving epidural analgesia. It is unclear whether these institutions have developed local protocols that are sensitive to patients' needs. Labor results in severe pain for many women, and there is no other circumstance where it is considered acceptable for a person to experience untreated severe pain, amenable to safe intervention. Therefore, the American College of Obstetricians and Gynecologists wishes to reaffirm the opinion published jointly with the American Society of Anesthesiologists that while under a physician's care, in the absence of medical contraindication, maternal request is sufficient medical indication for pain relief during labor. Decisions regarding analgesia should be coordinated among the obstetricians, the anesthesiologist, the patient, and support personnel.

How does pain relief affect the baby?

Does epidural cause elevated temperature?

Side effects of medicated methods:
The anesthesiologist takes special precautions to prevent complications. Although side effects are rare, they occasionally include the following. Some of the side effects may be specific to the circumstances of your presentation. Therefore you should discuss them with your anesthesiologists.

Shivering: Shivering may occur and is a common reaction. Sometimes it happens during labor and delivery, even if you have not received any anesthetic medications. Keeping you warm often helps it subside.

Decreased blood pressure: You will receive intravenous fluids and your blood pressure will be carefully monitored and treated. Decreases in blood pressure are expeditiously corrected.

Mild itching during labor: This is a result of narcotics used in the epidural/spinal medications. If itching becomes bothersome, your anesthesiologist can treat it with medications. Most women find itching to be mild.

Local anesthetic reaction: While local anesthetic reactions are rare, they can be serious. Be sure to tell your anesthesiologist if you ever had any allergic reaction to local anesthetic medications.

Breathing problems: On rare occasions, the anesthetic medication may affect the chest muscles and make it harder to breathe. Oxygen can be given to relieve this and help the breathing.

Injection into veins: The veins located in the epidural space become swollen during pregnancy. There is a risk that the anesthetic medication could be injected into one of them. To help avoid unusual reactions stemming from this, your anesthesiologist will first administer a test dose of medication and you may be asked if you notice any dizziness, a funny taste, numbness of ears, dizziness or rapid heart beat.

Persistent pain in some areas/no pain relief: Sometimes the anesthetic does not reach an area leaving a "spot" which is still painful. Your anesthesiologist may change your position on the bed or withdraw the epidural catheter to relieve the pain. Occasionally the epidural catheter may need to be removed and reinserted again if you do not get adequate pain relief. Your anesthesiologist will work with you to make you comfortable.

Paresthesias (feeling of nerve sensations): Transient "Feeling of nerve sensations/electric shock" (hitting your funny bone) can occur while inserting the epidural catheter as it brushes against the nerves in the epidural space. Although these sensations are common during epidural injections, permanent nerve damage is extremely rare.

Back pain: You may have localized back pain from the needle insertion, which should last a day or so. On the other hand, you may experience generalized back pain, which is not necessarily attributable to the epidural. Studies have shown that mothers who have natural childbirth deliveries are as likely to experience generalized back pain lasting a few days as those who have epidurals. It seems that pregnancy itself can increase the incidence of back pain because of softening of the ligaments resulting in back strain.

Headache: There may be several reasons why you can get a headache after labor and delivery that are unrelated to epidural anesthesia. However, although uncommon, a headache may develop following the epidural block procedure (<1%). this occurs as a result of a needle hole in the sac containing fluid (spinal fluid) during the epidural procedure. leakage of spinal fluid into the epidural space may result in headache. by holding as still as possible while the epidural needle is placed, you help to decrease the likelihood of a headache. usually the headache occurs in about 24 hours following the epidural block. typically, the headache occurs while you sit up and relieved by assuming lying down position. the head and neck discomfort sometimes lasting few days, often can be reduced or eliminated by simple measures such as lying flat, drinking fluids and taking pain tablets. occasionally, a patient may need additional treatment if the headache persists, or associated with other features such as nausea, difficulty in seeing light, or hearing noises.

A major complication such as nerve damage, bleeding into the epidural or spinal space, paralysis, and infection are extremely rare events.

Since epidural anesthesia involves needle placement in the back, there is a natural tendency to assume that any post-delivery nerve problem is due to the epidural anesthesia. however, the majority of nerve problems following labor and delivery are commonly due to the impinging of the nerves by the moving baby along the birth canal, and rarely to regional anesthesia. if you experience any weakness in the legs or other nerve problems, your anesthesiologist will help to evaluate the problem and make sure you have the proper follow-up.

3. Anesthesia for cesarean delivery:

There are instances when a vaginal delivery is not possible, in these cases a cesarean delivery may be the best option for mother or baby. Cesarean delivery may be done with regional or general anesthesia depending on the specific situation.

Regional anesthesia for cesarean delivery

  • S pinal
  • Epidural

Spinal/epidural
General anesthesia
Post-operative pain relief

Further reading:

  1. History of Obstetric Anesthesia. In Obstetric Anesthesia. Chestnut D.H. Mosby; 1999.
  2. The Work of Sir JY Simpson. Volume II. Editor: Simpson WG. Adam and Charles Black, 1871.
  3. Mrs. Longfellow. Selected Letters and Journals of Family Appleton Longfellow (1817-1861). Editor: Wagenknecht, E. Longmans, Greens, 1956
  4. Eappen S, Robbins D., Nonpharmacological means of pain relief for labor and delivery, Int Anesthesiol Clini. 2002 Fall; 40(4): 103-14, Review
  5. Simkin P., Nonpharmacologic relief of pain during labor: Systematic reviews of five methods, Am J Obstet gynecol, 2002 Volume 186, Number 5, S131-159.
  6. Datta S. Childbirth and pain relief. Next Decade, Inc.2001

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