Most babies are born following approximately nine calendar months of pregnancy. Delivery between 37–42 weeks of gestation is considered normal and full-term. A baby born prior to 37 weeks of gestation is considered premature, or preterm. After 42 weeks, it is considered postterm. Each of the latter circumstances is considered a higher risk delivery.
Labor occurs in three stages. The first is the dilation of the cervix, the second is the delivery of the baby, and
the third is the expulsion of the placenta. However, approximately 25% of babies born in the United States are surgically delivered by Caesarean section. This can be a necessary and even life-saving procedure, but this percentage is probably much larger than it could be with better management of labor and more informed birthing consumers.
A 2001 report showed that older pregnant women are more likely to deliver via Caesarean and also may more likely required induced labor. At one time, "once a Caesarean, always a Caesarean" meant a woman could not deliver vaginally after having a Caesarean, but that is no longer true for everyone. Women who have had previous surgical deliveries are increasingly choosing vaginal birth after Caesarean (VBAC). Having a sympathetic, informed caregiver and preparation helps achieve this goal.
The first stage of labor is the time that is required for the cervix to reach full dilation. It includes latent (early), active, and transition phases. The latent phase of labor, when the cervix progresses from being closed to 3 cm open, may last for days or longer. For some women, latent labor is not a distinguishable phase, and for others it leads immediately into active labor. The latent phase is often exciting for the mother, who wonders if her baby is finally going to be born. Contractions during this phase are not very painful. Active labor ensues around the time the cervix reaches 3 cm dilation, and continues until approximately 7 cm dilation. At this stage, labor contractions are powerful, and require the mother's concentration. The length of this stage is also variable, and is usually longer for first-time mothers than for those having subsequent babies. Active labor is followed by transition. This is the shortest and most intense stage of labor, when many women express feelings of despair, or "not being
able to do it anymore." At the end of transition, the cervix is fully dilated to 10 cm, and pushing can begin.
The second stage of labor is pushing the baby out through the vagina (birth canal). Contractions are generally less frequent than in the first stage of labor, but are very strong and long lasting. Many women find it a relief to be able to push. In the unmedicated mother, pushing is reflexive and instinctual. The pressure of the baby's head on stretch receptors in the maternal pelvis triggers the urge to push. Pushing is another phase where nature gives credit to the woman who has had a previous birth. First-time mothers generally push for about 60 minutes; subsequent births require an average of only 15 minutes.
The third stage of labor is the delivery of the placenta, which often goes unnoticed by the mother who is attending to her newborn. After the baby is delivered, the uterus should continue to contract in order to push out the placenta. This organ functioned to bring the baby nourishment from the mother throughout the pregnancy, and return the child's waste products to the mother to be excreted. If contractions become sluggish or stop before the placenta is delivered, breastfeeding the baby can trigger the release of the hormone oxytocin to stimulate the uterus to contract again. Alternatively, artificial oxytocin (pitocin) can be given by injection.
Causes & symptoms
The onset of spontaneous labor may be marked by irregular contractions, not very different from the Braxton-Hicks contractions that are common throughout late pregnancy. In approximately 10% of spontaneous labors, rupture of membranes ("water breaking") may occur before the onset of contractions. Since prolonged rupture of membranes prior to delivery presents a risk of infection, the care provider for the mother should be contacted whether or not she is experiencing contractions.
Even experienced mothers sometimes have difficulty telling when labor begins, as prelabor may occur on and off for days or longer before settling into a regular pattern. In general, the contractions associated with labor will gradually get more frequent, more regular, longer, and stronger. Walking or changing activity will not alter them. These contractions are effective at changing the cervix, which will become appreciably lower, thinner, and more dilated. By contrast, contractions of prelabor stay about the same intensity and frequency. A change of activity will often make them disappear. These contractions may be uncomfortable, and may even cause some mild cervical changes, but there is not a change on an hourly basis.
For women who choose to deliver in a hospital, a diagnosis of active labor is generally made if contractions are regular and strong, and the cervix is effacing and/or dilating noticeably on an hourly basis. A woman who arrives at the hospital reporting regular contractions who has no complicating factors is generally observed for at least an hour to see whether her labor will progress. Monitors that fit around the abdomen measure the fetal heart rate, and the nature of the contractions. A nurse will check the position and station of the baby, as well as the effacement, dilation, and position of the mother's cervix. Admission is generally made regardless of progress if the water has broken (rupture of membranes), or if there are complications, such as high maternal blood pressure, more than one fetus, fetal distress, abnormal fetal presentation, or excessive bleeding. Women delivering before 37 weeks or after 42 weeks of gestation are also well-advised to deliver in a hospital.
For a routine, uncomplicated labor and delivery, the primary treatment required is assistance with comfort measures. What each mother finds comforting is very individual. At some point during the pregnancy, it is a good idea to make a list of things to try to relieve pain during labor, in the event that one or two favored techniques don't work. A mother who generally enjoys massage may suddenly discover that it is distracting to be touched during active labor; one who plans to rely on medication could have an epidural that does not take, or be laboring too quickly for it to be allowed. Having a list of comfort measures to refer to will be useful and reassuring
Fear of the unknown can certainly contribute to increased pain. Expectant parents should learn all they can about the process of childbirth. Many good reference books are available. Taking Lamaze classes lends a personal touch, and many couples enjoy the camaraderie of sharing the learning experience with other expectant families. Even though labor can take unexpected turns, being aware of the options at each stage will lend some perception of control. Making a list of birth preferences can be helpful in defining what the parents desire at the birth, but flexibility is important to avoid disappointment if every expectation is not met.
A skilled acupuncturist may be able to offer some relief of labor pain, particularly for women who have previously found acupuncture to be helpful with other types of pain.
Some women find massage or therapeutic touch to be quite relaxing during labor. Contractions are sometimes felt quite intensely in the back, and a combination of massage and counterpressure can offer relief. Foot massage may also be comforting, both during pregnancy and labor. There is a great temptation for the laboring woman to tense her abdomen against a contraction. The contraction will be more effective and less painful with effleurage (light stroking) of the area, and a verbal reminder to let the abdomen hang heavy and relax. The jaw area is also frequently clenched, and benefits from relaxation. Gentle touch and massage of any area that appears tense will help to relieve stress. This is a good technique to practice before labor begins.
The sounds of a favorite piece of music can be an excellent aid to relaxation. Instrumentals are generally preferable to singing. Soothing sounds or tunes that evoke happy memories are helpful. Some women enjoy tapes of nature sounds.
A warm tub or shower may be one of the most underestimated methods of relieving the pain of labor. Warmth encourages muscle relaxation, which in turn decreases anxiety. The water in a tub also supports the mother's body. In
a jetted tub, position and water pressure can be adjusted to soothe areas that are cramping or painful. This may be particularly comforting for back labor. In a birthing pool or large tub, the mother is free to move around and find a position that optimizes her comfort. The relaxation brought on by water can make for a shorter, more comfortable labor.
Some essential oils are particularly recommended during birth for those women who enjoy the scents. They can be added to a diffuser or a crock-pot of water in the birthing area, emitted from a scented candle, or concentrated drops of the scent can be placed on the pillow and bed linens. Clary sage and lavender are popular choices, but any scent that is pleasant to the mother may be used.
The use of visualization, or guided imagery, can be powerful to promote relaxation and the progress of labor. One exercise that can be practiced in advance of labor is choosing a place or image that the mother associates with comfort, security, and serenity. This place can be imagined and explored at any time to help relieve stress. If the details of this visualization are shared with someone who will be present during labor, that person can help to evoke those feelings during times of pain or stress. Another popular visualization is that of a flower blooming. The cervix can be envisioned as a flower bud that gradually opens to allow the baby to descend. Other scripts for guided imagery can be practiced to relieve stress and reduce pain.
Increasingly, women (not in high-risk pregnancies) desire a more "low-tech" approach to labor and choose a nurse midwife to assist them rather than a physician. For thousands of years, midwives have given women support
Modern pain relief for childbirth generally involves the use of medication. Although medication has evolved from the days of mothers being put under "twilight sleep" for a normal vaginal birth, the use of chemical pain relief is not without risk.
Undoubtedly one of the most common pain relief methods during labor is the epidural. This technique involves the injection of anesthetic medication through a catheter into the epidural space in the back. Epidurals often provide excellent relief of pain from contractions, episiotomy, and perineal repair. They do not impair the mother's mental alertness, although she may sleep if labor to that point has been long and arduous. The disadvantages of epidurals include possible prolonging of labor, impaired ability to push, inability to move around, possible need for bladder catheterization and accompanying risk of infection or injury, maternal low blood pressure, maternal fever, spinal headache from inadvertent injection into the subdural space, and patchy or ineffective blocks. Low blood pressure can result in nausea and dizziness, as well as fetal distress. Supplemental oxygen may be given to the mother to alleviate this effect. Allergic reactions to the anesthetic agents occur rarely. The woman who wishes to have an epidural needs to have IV access, IV fluids in advance to help prevent low blood pressure, and fetal monitoring. The woman's inability to move around and change positions because of the tubes and wires can impede the progress of labor. If labor slows, it may be augmented by the injection of pitocin. Assisted delivery via forceps or vacuum extractor may be necessary if the mother finds herself unable to push effectively.
Injectable narcotic pain medications are also available. They can be given by either intramuscular (IM) or intravenous (IV) routes. When given intravenously, the effects are felt sooner and are shorter in duration. These medications are more likely to affect the fetus, and are generally not given late in labor. Some women say that their pain is not greatly diminished, but that they are better able to rest between contractions. Others experience side effects, such as nausea, vomiting, and dizziness that they feel negate any benefit that they get from the medication.
Techniques that are used to prevent pregnancy are known as contraception. Some methods require a prescription, including those involving hormones, diaphragms, cervical caps, or intrauterine devices (IUDs). Hormonal birth control is available as a daily pill, an injection, or an implant. Consultation with a health care professional will determine the appropriateness of these methods. Conditions including clotting diseases, breast cancer, and liver disease will preclude hormonal forms of birth control. Significant side effects may occur even in women who are good candidates for these methods. Timing of taking the daily birth control pills is important, and back-up methods should be available if doses are missed. Diaphragms and caps are both barriers used next to the cervix along with a spermicide. For both methods, there is a pregnancy rate between 8% and 27% in the first year. The IUD is a uniquely long-term device. It is placed by a medical professional, and depending on the type, can retain effectiveness for as long as 10 years. It is not recommended for women who have ever had pelvic inflammatory disease, or for those who are not in a mutually monogamous relationship. The pregnancy rate in the first year for IUD users is around 3%.
Several popular forms of birth control are nonprescriptive. Barrier method materials, such as condoms, foam, and spermicides are available over the counter. Condoms have the distinction of being the only type designed for males. Used correctly, they are highly effective in preventing pregnancy. They have no side effects, and latex varieties have the additional advantage of providing some protection against sexually transmitted diseases. Average pregnancy rates are around 12%.
Periodic abstinence, sometimes called natural family planning, requires training and attentiveness to physical signs. A variety of methods are available, and may include monitoring of cycle days, basal body temperature, cervical mucus characteristics, and other symptoms related to the timing of ovulation. Effectiveness can be as great as 93%, but it requires significant commitment for the couple to faithfully monitor signs and abstain from intercourse for at least one week of every cycle. Women with irregular cycles or unreliable signs have the most unplanned pregnancies with these methods.
Levchuck, Caroline M., Jane Kelly Kosek, and Michele Drohan. "Certified Nurse-Midwife." In Healthy Living. UXL, 2000.
Sears, William, and Martha Sears. The Birth Book. Boston: Little, Brown and Company, 1994.
Stoppard, Miriam. New Pregnancy and Birth Book. New York: The Ballentine Publishing Group, 1999.
Ecker, Jeffrey L., et al. "Increased Risk of Caesarean Delivery with Advancing Maternal Age: Indications and Associated Factors in Nulliparous Women." American Journal of Obstetrics and Gynecology 185, no. 4 (October 2001): 883–885.
Association of Labor Assistants and Childbirth Educators (ALACE) (formerly Informed Birth & Parenting). P.O. 382724. Cambridge, MA, 0228-2724. (617) 441-2500 or local (818) 358-2318.
International Childbirth Education Association (ICEA). P.O. Box 20048. Minneapolis, MN 55420-0048. (612) 854-8660. <http://www.icea.org>.
Teresa G. Odle
- —Mild, painless contractions of prelabor.