The final post in this blog series will examine the pros and cons of assuming a lateral lying position during the second stage of labor as compared to dorsal lithotomy position. Anatomical implications, perineal outcomes, and orthopedic concerns will all be addressed.

Anatomical implications
As discussed in earlier posts, dorsal lithotomy puts the birth canal in an "uphill" orientation. Conversely, the lateral lying position places the birth canal in a gravity-eliminated orientation, allowing the laboring mother to have a mechanical advantage during the pushing stage. Also, when in side lying on the left side, there is optimal blood flow as compression of the inferior vena cava by the uterus is avoided.

Perineal outcomes
Shorten (2002) compared birth positions, Accoucher, and perineal outcomes in almost 2900 births. It was found that the lateral lying position produced quite favorable results with regards to the health of the perineum. Below average rates of episiotomy were observed and intact perineums were seen in 66.6% of the women who delivered while lying on their side. The lateral lying position was, by far, the best choice for decreasing the risk for tears and the need for sutures in their research.

In a study by Soong (2005), the need for perineal sutures was decreased when a lateral lying position was assumed during delivery with epidural anesthesia. The semi-recumbent position was associated with an increased need for suturing. If a woman does choose to receive an epidural during her labor, it is important to realize that there are a fewer number of possible positions that she can assume because of the effects of the anesthesia. However, given the aforementioned study by Soong, a woman should be able to make an informed decision about what position may be the best choice to improve perineal outcomes.

Orthopedic concerns
Although the lateral lying position does not have as many advantages as, for example, squatting or quadruped during a "normal" birth, it does have many indications when looking at births that involve a mother with orthopedic issues present. One example is when a woman is suffering from coccygeal (tailbone)pain. Lateral lying may be the best choice for her to be in as this position does not place any force on this area and also allows the coccyx to move freely and out of the way as the baby descends. Furthermore, it may be helpful to the woman who has pubic symphysis dysfunction, if careful attention is given to not overly abduct the lower extremities, placing undue stretch to the already separated joint.

In consideration of the spine, the side lying position is beneficial to keep the lumbar spine in a flexed position when spondylolisthesis or spinal stenosis are present. The amount of flexion may be easily adjusted to maintain or improve maternal comfort during second stage and may improve her ability to recruit the proper musculature to push, if pain due to spine impairments is decreased.

Lastly, the lateral lying position may be optimal if hip joint dysfunction, knee joint dysfunction or superficial/deep vein thrombosis (while lying on unaffected side) is present (Hobel 2004). Once again, attention must be paid to avoid end ranges of motion to decrease strain on the hip and knee joints and decrease risk for further injury. (See previous posts in this series for further discussion on the above-mentioned orthopedic conditions)

Summary
I have covered many advantages and disadvantages over the last three posts when considering second stage labor positions. It is important to note that further research is needed in this area so we may better understand the implications of each position. Likewise, additional information will further support our education of women on optimal second stage positioning. There are many different individual concerns of every woman, in every circumstance, in every birth. It is my hope that women everywhere will be empowered to make an informed decision according to what birth outcome is important and specific to them based on the evidence presented in these posts.

picture source: http://www.flickr.com/photos/joygant/1447261129/

References

Gardosi, J., Sylvester, S. and B-Lynch, C. (1989), Alternative positions in the second stage of labour: a randomized controlled trial. BJOG: An International Journal of Obstetrics & Gynaecology, 96: 1290-1296.

Hobel CJ, Chang AB. "Normal Labor, Delivery, and Postpartum Care:

Anatomic Considerations, Obstetric Analgesia and Anesthesia, and Resuscitation of the Newborn" in Essentials of Obstetrics and Gynecology, 4th Edition, Editors Hacker, Moore, Gambone. Elsevier Saunders:

Philadelphia. 2004.

Liddell, H. S. and Fisher, P. R. (1985), The Birthing Chair in the Second Stage of Labour. Australian and New Zealand Journal of Obstetrics and Gynaecology, 25: 65-68

Oxorn, Harry MD Human Labor and Birth (University of Ottawa, Ontario, Canada,McGraw-Hill Professional Publishing)1986

Sax TW, Rosenbaum RB. Neuromuscular disorders in pregnancy. Muscle Nerve. 2006 Nov; 34(5):559-71

Shorten, A., Donsante, J. and Shorten, B. (2002), Birth Position, Accoucheur, and Perineal Outcomes: Informing Women About Choices for Vaginal Birth. Birth, 29: 18-27.

Snow, R., Neubert, A. Peripartum Pubic Symphysis Separation: A Case Series and Review of the Literature. Obstetrical & Gynecological Survey: July 1997 - Volume 52 - Issue 7 - pp 438-443

Soong B, Barnes M. Maternal position at midwife-attended birth and perineal trauma: is there an association? Birth. 2002;32(3):164-169.

Posted By: Amanda Blaz, DPT

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