Note: I could only find the second and third pages of the article below among my computer notes, but I will try hard to find page one. Stay tuned.
... pelvis. The mobility allows the fetus to move about and adjust to the pelvis, eliminating long periods in which the cord is compressed. Flynn and Kelly repeated their study in 197817 and found the same results. Finally, it should be emphasized that in all the studies comparing ambulation with recumbency in labor, the women preferred the upright or ambulatory positions over the recumbent ones. They felt less pain. Although it was not measured quantitatively, we can predict that women who felt less pain also felt less fear. This would be a good avenue for research. One could compare catecholamine release in women who are laboring in various positions. I would predict that if women are more comfortable - and in a less passive and more active role during labor - they will also be less afraid. Thus they will secrete less of the "flight-or fight" hormones, epinephrine and norepinephrine. 'l'hese have been iound by many investigators to reduce uterine circulation markedly and are known to decrease uterine contractions.
The positions for giving birth have been subject to some of the same influences that have changed positions for labor; lithotomy is now nearly universal in Western birth. The lithotomy position is in direct contradiction to basic principles of anatomy and physiology. It has been adopted primarily to provide for the comfort and efficiency of the birth attendant. Lithotomy provides ready access to the perineum for forceps and episiotomy, for manual examinations and maneuvers, and for use of anesthetics and repair.
Historically, however, babies have arrived with their mothers squatting, kneel-ing, sitting, semi-reclining, lying down, on all fours and sometimes standing. These positions promote the use of the mother's own bearing down efforts to be aided by gravity. They provide for the chest and pelvis to be fixed by pelvic rock, and for flexion of the torso to occur. Both the anterior abdominal muscles and the thighs exert pressure on the uterine wall in most of these upright positions. Physiologically, the lithotomy position is the worst possibre position one could imagine. Not only is it impossible to use the thighs to press on the abdominal wall with pushes, but one is pushing the baby uphill, against any help gravity could contribute! What sense does that make? Having the legs far apart also pulls the perineal fascia taut, narrowing the introitus, and actually making it prone to tearing. Mothers also complain of back pain in the lithotomy position. Sometimes, they experience decreased circualtion to the lower extremities due to the lithotomy position.
The delivery table is relatively new in the history of human birth. It was developed and refined to assist the mother into the lithotomy position. There are many new types being manufactured - tables with stirrups that detach, that pop out when one presses a button, beds that fold in half, raise at the foot or head, and some that look like early American furniture. All have common faults. When the table/bed is removed at the woman's hips, suddenly part of her physical support is wiped out from under her. The woman is usually forced to be supine; her legs are in the air, spread out, and strapped into position. The mattress is often so thin over the steel bedframe that one cannot maneuver the baby's shoulders out during some births. One needs a softer mattress under the mother for that. Delivery tables are needed if one must use forceps or an episiotomy, but for most births, they restrict what both mothers and attendants can do at birth.
Some think that propping the mother up on the delivery table 30° solves many of these problems. However, in such a position, the mother still cannot flex her torso enough to make good expulsive efforts. Yes, she can bear down, but not nearly as effectively as if she was sitting more upright. There is still the risk of supine hypotension, as was explained above, and most of the other problems are still present, as well.
We have started a return to the birthing chair or stool in our practice, in order to utilize the forces of gravity and place the mother in a position that avoids supine hypotension, aortic compression, and umbilical cord compression. This is perhaps the optimum position for birth, as the muscles of the anterior abdominal wall exert a compressive force, with the pelvis fixed in a pelvic rock. The spine can be curved and is not flat. The woman can perform the valsalva maneuver in an upright position much more effectively than when lying flat or propped at 30°.
REFERENCES
1. Schwarcz R.L., et al: Fetal and maternal monitoring in spontaneous labors and in elective inductions: A comparative study. Am J Obstet Gynecol 120:356-62, 10 Oct 1974.
2. Leijon I., et al: Spontaneous labour and elective induction&emdash;a prospective random- ized study. Behavioural assessment and neurological examination in the newborn period. Acta Paediatr Scand 68:553-60, Jul 1979.
3. Brackhill Y.: Obstetrical medication and infant development. In Osofsky (Ed.), Handbook of Infant Development. New York, Wiley, 1978. (31 other related studies)
4. Martell M., et al: Blood acid-base balance at birth in neonates from labors with early and late rupture of the membranes. J Pediatr 6:963-7, Dec 1976.
5. Caldeyro-Barcia R., et al: Adverse effects of early amniotomy during labor, in Gluck L (Ed.). Modern Perinatal Medicine, Chicago, Year Book Medical Publishers, Inc., 1974.
6. Haire D.: The Cultural Warping of Childbirth. Wisconsin, International Childbirth Education Association, 1972.
7. Newton N. and Newton M.: Childbirth in cross-cultural perspective, in Howell J G (Ed.), Modern Perspectives in Psycho-Obstetrics. Brunner/Mazel, New York, 1972.
8. Englemann G.: Labor Among Primitive Peoples. Burke, Cleveland, 1882.
9. Liu Y.: Position during labor and delivery: History and perspective. J Nurs Midw 24: 23-6, May-June 1979. 10. Koberts J: Alternate positions for childbirth. I. First Stage. J Nurs Midw 25:11-18, Jul-Aug 1980.
11. Caldeyro-Barcia R., Noriega-Guerra L, Cibils LA, Alvarez H: Effect of position changes on the intensity and frequency of uterine contractions during labor. Am J Obstet Gynecol 80:284, Aug 1960.
12. Caldeyro-Barcia R, Bieniarz J, Maqueda E: Compression of the aorta by the uterus in late human pregnancy. Am J Obstet Gynecol 95 :795, 15 Jul 1966.
1. Bieniarz J, Caldeyro-Barcia R, Hashimoto T: Obstruction of the common iliac artery by the contracting uterus. f. J Jap Obstet Gynecol Soc (English) 13: 16, Jan 1966.
14. Mendez-Bauer C., et al: Effects of standing position on spontaneous uterine contractil- ity and other aspects of labor. J Perinat Med 3 :89- 100, 1975.
15. Huch A. and Huch R.: Transcutaneous, non-invasive monitoring of PO2. Hosp Pract 11 :6, Jun 1970.
16. Flynn A.M. and Kelly J.: Continuous fetal monitoring in the ambulant patient in labour. Br. Med J 2:842, 1976.
I 7. Flynn A.M. and Kelly J.: Ambulation in labour. Br Med J 2: 591-3, Aug 1978.
18. Hughey M.J., et al: The effect of fetal monitoring on the incidence of cesarean section. Obstet Gynecol 41 :513, May 1977.
19. Ueland K. and Hansen J.M.: Maternal cardiovascular dynamics II: Posture and uterine contractions. Am J Obstet Gynecol 103:1, 1 Jan 1969.
20. Gabbe S.G., et al: Umbilical cord compression associated with amniotomy: laboratory observation. Am J Obstet Gynecol 126:353, 1 Oct 1976.
21. Birth and the Family Journal Vol 7:4, Winter, 1980
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