principles and practice Reevaluating Positions for Labor-Lateral vs Supine SUSAN BOND, RN, RSN

Studies have shown that the lateral positimi is often viore adaantageuus tban the supine position. Reviewed here are data on when and why rbc lateral position is preferred during labor to positively affect the cardiovnscrrlnr systent md the urinary and respiratory tracts and to regulate uterine contractions. Advantages of the supine Fosition are also discussed.

How many times have you heard a nurse or doctor tell a patient in labor, “Lie on your back and the cervix will dilate faster,” or “If you lie on your side your labor will last Ionger because the baby’s head will not come down”?

These are only two of the many common mis- conceptions about positioning during labor. Rela- tively little research has been done on this aspect of childbirth, and unfortunately, very few obstetric teams apply the information that is available.

Research has shown that position affects virtu- ally every body system and can therefore affect the normality and duration of labor, as well as influence the safety and welfare of mother and baby.

Studies also indicate that, in most instances, the lateral position is more advantageous than the supine during labor. Yet much too often, the supine position is forced on patients solely for the con- venience of the OB team. Indeed, our practice of keeping laboring patients on their backs has be- come so routine that many patients are totally unaware that they can assume another position and will often ask permission to turn on the side.

Following is a summary of data collected from a variety of research studies on positioning. Cited are the advantages of the lateral position over the supine to the cardiovascular system and the urinary and respiratory tracts. Use of the lateral position to regulate uterine contractions and for other aspects of labor is covered, and instances in which the supine position is preferred are given. T h e purpose here is to make the data more readily available for clinical application in obstetric nursing.

Benefits of the Lateral Position to Body Systems

Cardiovascular System

A11 output determinations are higher when the left side position is assumed.’ T h e lateral position may be useful to patients with the following con- ditions.

a. Congestive heart failure, shock, or other con- ditions in which cardiac output is diminished.2

b. Preeclampsia or eclampsia because blood pres- sure determinations are lower during contractions than when the supine position is

c. Obstetric complications, such as abruptio placenta, prolapsed cord in which increase or maintenance of the uterine blood flow benefits the mother or baby.2

d. T h e “Poseiro Effect,” seen in 15-20% of parturients. T h e condition occurs only when the supine position is used. Femoral arterial pressure and femoral pulse decreases due to compression of the lower aorta and the common iliac arteries by the u t e r u ~ . ~

e. “Supine Hypotensive Syndrome,” seen in lO-lS% of gravidas. Turning the patient on her left side eliminates this condition, which is due to compression of the inferior vena cava by the gravid uterus. Diminished venous return and cardiac out- put cause severe arterial hypotension, which can result in profound shock and placental abruption.’

Urinary Tract

Urinary output can be increased when the pa- tient assumes the lateral position. This reduces the

Nocember/December 1973 JOGN Nursing 29

need for catheterization, thus avoiding undue em- barrassment and discomfort and the risk of urinary tract infection.

The lateral position can also relieve relative oliguria which may persist for hours. It it postu- lated that this condition is due to reduction of renal blood flow and glomerular filtration rate when the inferior vena cava, renal vessels, or the kidney itself are compre~sed.’~~

Respiratory Tract

The lateral position may relieve shortness of breath and other discomforts caused by pressure of the enlarged uterus on the d ia~hragm.~

Use of Lateral Position to Regulate Uterine Contractions

Contractions are less frequent and more intense when the patient is in a lateral po~i t ion.~ Therefore, the side position may be useful in relieving excess tonus or contractility sometimes found in the supine uterus.

Heightened intensity of contractions may shorten the labor process. When the patient is on her side, contractions are usually better coordinated and therefore more effective in producing cervical effacement and dilatatior~.~

Other Advantages of the Lateral Position

The side position can help alleviate discomfort associated with “back labor” by decreasing the pressure of the presenting part on the sacral area.‘ It also facilitates drainage from the pharynx if the patient vomits.

Finally, this position is preferred when either caudal or epidural anesthesia is used.

Advantages of the Supine Position over the Lateral

Easier access to the patients by members of the health care team seems to be the main advantage of the supine position. It is preferred for fetal mon- itoring, auscultation of fetal heart tones, monitoring contractions, and performing rectal and vaginal examinations. When the patient is supine during the transition stage of labor, it is easier for the nurse to observe for show, buldging of the perineum, perineal pressure, and c r o ~ n i n g . ~ ~ ~

This position promotes relaxation early in labor, especially if the knees and hips are slightly flexed to allow for relaxation of the abdominal wall, and it is the desired position for pushing during the later stages of l a b ~ r . ~ , ~

Comments

The nurse should be familiar with available in- formation on the use of positioning to enhance patient comfort and safety. She can suggest posi- tion changes and explain to patients how these changes can help alleviate discomfort. Staff edu- cation through inservice programs would be a step in the right direction.

There is a need for further resarch on positioning. Some questions that might be answered include the following:

1. What are the effects of various positions on fetal heart rate and position?

30 Novernber/Decernber 1973 JOGN Nursing

2. To what degree can certain positions shorten or prolong labor?

3. How does freedom of movement affect the reactions and perceptions of patients who are en- couraged to assume different positions during labor?

4. Is it necessary to limit positioning techniques by keeping patients in bed throughout labor?

5 . What other positions are appropriate during labor and how do they affect body homeostasis?

Natural childbirth enthusiasts are instructed in the use of labor positions ranging from the knee- chest position to tailor sitting, squatting, and kneel- ing on all fours. Hopefully, the increasing interest in natural childbirth will stimulate further interest in positioning, discussions and demonstrations of various positions will be included in all prenatal instruction in the future, and such data as presented here will become an integral part of the body of knowledge in obstetric nursing.

References

1, Bonica, John: Principles and Practice of Obstetric Analgesia and Anesthesia, Vol 2. Philadelphia, F. A. Davis Company, 1969

2. Vorys, Nichols, et al.: “The Cardiac Changes in Various Positions in Pregnancy.” A m J Obstet Gynecol

3 . Bonica, John: Principles and Practice of Obstetric Analgesia 82:1312-1321, 1961

and Anesthesia, Vol. 1. Philadelphia, F. A. Davis Company, 1969

Position on Renal Function in the Near Term Pregnant Woman.” J Clin Invest 34:777-781, 1955

5 . Barcia, Roberto, et 01.: “Effect of Position Changes on the Intensity and Frequency of Uterine Contractions During Labor.” A m J Obstet Gynecol 80:284-290, 1960

4. Pritchard, Jack, and Allan C. Barnes: “Effect of Supine

6. Bing, Elizabeth: Six Practical Lessons for an Easier

November/December 1973 JOGN Nursing

Childbirth. New York, Grosset and Dunlap, Inc. (Bantam Books), 1967

7. Wiedenbach, E.: Family-Centered Maternity Nursing. New York, G. P. Putnam’s Sons, 1967

8. Fitzpatrick, E., J. Nicholson, and S. Reeder: Maternity Nursing. Philadelphia, J. B. Lippincott Company, 1966

Supplemental Bibliography

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Cappe, Bernard E., and Sylvan N. Surks: “Inferior Vena Cava Syndrome in Late Pregnancy.” Am J Obstet Gynecol 89:162, 1960 Hendricks, Charles H., and Allan C. Barnes: “Effect of Supine Position on Urinary Output in Pregnancy.” A m ] Obstet Gynecol69:1225-1232,1965 Hendricks, Charles H., and Edward J. Quilligan: “Cardiac Output During Labor.” Am J Obstet Gynecol

Howard, Benk, James Goodson, and William F. Mengert: “Supine Hypotensive Syndrome in Late Pregnancy.” Obstet Gynecol 1:371-377, 1953 Marx, Gertie F., et 01.: “Cerebrospinal Fluid Pressures During Labor.” Am J Obstet Gynecol 84:213-219, 1962 Quilligan, Edward J., and Carl Tyler: “Postural Effects on Cardiovascular Status in Pregnancy: A Comparison of Lateral and Supine Postures.” Am J Obstet Gynecol 78:465-471, 1959 Wright, Liam: “Postural Hypotension in Late Pregnancy.” Br Med J 1:760-762, 1962

71~9.53-972,1956

Address reprint requests to Susan Bond, RN, 804 Gloria Place, Virginia Beach, VA 23454.

The author is Staff Nurse on the Surgical Unit at General Hospital of Virginitz Beach, Virginia. A graduate of the Medical College of Virginia, Health Sciences Division of Virginia Cormuonwealth University, she is interested in various aspects of prenatal teaching, Lamaze and other methods of natural childbirth and widwifery.

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