OJOG  Vol.4 No.6 , April 2014
Predicting Birth-Related Levator Ani Tear Severity in Primiparous Women: Evaluating Maternal Recovery from Labor and Delivery (EMRLD Study)
Abstract: Objective: To determine which maternal characteristics or birth events independently predict severity of levator ani muscle (LA) tears at first vaginal birth in a longitudinal/observational investigation in a tertiary care hospital. Sample: Ninety primiparas with at least one at risk for LA tear inclusion factor at vaginal birth: maternal age ≥ 33 years, second stage ≥ 150 minutes, macrosomia, instrumented delivery, and/or anal sphincter laceration were studied. Methods: Magnetic Resonance Imaging (MRI) was obtained early postpartum (mean ± sd 48.9 ± 21.6 days) to identify LA tear. Severity of LA muscle fiber loss was graded on an ordinal scale of: “0” as no loss, “1” as <50% unilateral loss, “2” as ≥50% unilateral or <50% bilateral loss, and “3” as ≥50% bilateral loss. Data were analyzed using proportional odds modeling. Inclusion factors were explored as predictors of LA tear severity and at analysis episiotomy, time spent actively pushing, epidural, and oxytocin were also considered. The main outcome measures of interest included grading of severity of LA muscle fiber loss on an ordinal scale. Results: Respective counts/percentages of women within each 0 thru 3 ordered category of LA tear severity were: “0” = 58(64%), “1” = 9(10%), “2” = 15(17%), and “3” = 8(9%). Estimates and 95% CI for significant demographic or obstetric univariate predictors of LA tear severity level were age, OR 1.093 (CI 1.012 - 1.180), p = 0.023; and time spent in active pushing, OR 1.089 (CI 1.005 - 1.180), p = 0.038. The other factors considered were not significant. There were too few women with forceps deliveries to analyze. Conclusion: In our enriched sample of primiparous women, 26% showed a significant LA tear. Maternal age and time spent actively pushing independently predict LA tear severity.
Cite this paper: Low, L. , Zielinski, R. , Tao, Y. , Galecki, A. , Brandon, C. and Miller, J. (2014) Predicting Birth-Related Levator Ani Tear Severity in Primiparous Women: Evaluating Maternal Recovery from Labor and Delivery (EMRLD Study). Open Journal of Obstetrics and Gynecology, 4, 266-278. doi: 10.4236/ojog.2014.46043.

[1]   Lukacz, E.S., Lawrence, J.M., Contreras, R., Nager, C.W. and Luber, K.M. (2006) Parity, Mode of Delivery, and Pelvic Floor Disorders. Obstetrics and Gynecology, 107, 1253-1260.

[2]   Hendrix, S.L., Clark, A., Nygaard, I., Aragaski, A., Barnabei, V. and McTiernan, A. (2002) Pelvic Organ Prolapse in the Women’s Health Initiative: Gravity and Gravidity. American Journal of Obstetrics and Gynecology, 186, 1160-1166.

[3]   DeLancey, J.O., Morgan, D.M., Fenner, D.E., Kearney, R., Guire, K., Miller, J.M., et al. (2007) Comparison of Levator Ani Muscle Defects and Function in Women with and without Pelvic Organ Prolapse. Obstetrics and Gynecology, 109, 295-302.

[4]   Dietz, H.P. and Lanzarone, V. (2005) Levator Trauma after Vaginal Delivery. Obstetrics and Gynecology, 106, 707-711.

[5]   Lavy, Y., Sand, P., Kaniel, C. and Hochner-Celnikier, D. (2011) Can Pelvic Floor Injury Secondary to Delivery Be Prevented? International Urogynecology Journal, 6, 2011.

[6]   Shek, K.L. and Dietz, H.P. (2010) Intrapartum Risk Factors for Levator Trauma. BJOG, 117, 1485-1492.

[7]   Valsky, D.V., Lipshuetz, M., Bord, A., Eldar, I., Messing, B., Hochner-Celnikier, D., et al. (2009) Fetal Head Circumference and Length of Second Stage of Labor Are Risk Factors for Levator Ani Muscle Injury, Diagnosed by 3-Dimensional Transperineal Ultrasound in Primiparous Women. American Journal of Obstetrics and Gynecology, 201, e1-e7.

[8]   Chan, S.S., Cheung, R.Y., Yiu, A.K., Lee, L.L., Pang, A.W., Choy, K., et al. (2012) Prevalence of Levator Ani Muscle Injury in Chinese Primiparous Women after First Delivery. Ultrasound in Obstetrics & Gynecology, 39, 704-709.

[9]   Kearney, R., Miller, J., Ashton Miller, J. and DeLancey, J.O. (2006) Obstetric Factors Associated with Levator Ani Muscle Injury after Vaginal Birth. Obstetrics and Gynecology, 107, 144-148.

[10]   Dietz, H.P. and Shek, K.L. (2008) Validity and Reproducibility of the Digital Detection of Levator Trauma. International Urogynecology Journal, 19, 1097-1101.

[11]   Cassadó Garriga, J., Pessarrodona Isern, A., Espun Pons, M., Duran Retamal, M., Felgueroso Fabrega, A. and Rodriguez Carballeira, M. (2011) Four-Dimensional Sonographic Evaluation of Avulsion of the Levator Ani According to Delivery Mode. Ultrasound in Obstetrics & Gynecology, 38, 701-706.

[12]   Miller, J.M., Brandon, C., Jacobson, J., Kane Low, L., Zielinski, R., Ashton-Miller, J., et al. (2010) MRI Findings in Patients Considered High Risk for Pelvic Floor Injury Studied Serially after Vaginal Birth. AJR, 195, 786-790.

[13]   Brandon, C., Jacobson, J., Low, L., Park, L., DeLancey, J. and Miller, J. (2012) Pubic Bone Injuries in Primiparous Women: Magnetic Resonance Imaging in Detection and Differential Diagnosis of Structural Injury. Ultrasound in Obstetrics & Gynecology, 39, 444-451. uog.9082

[14]   McCullagh, P. (1980) Regression Models for Ordinal Data (with Discussion). Journal of the Royal Statistical Society, Series B, 42, 109-142.

[15]   Agresti, A. (2010) Analysis of Ordinal Categorical Data. 2nd Edition, Wiley, Malden.

[16]   Hsieh, F.Y., Block, D.A. and Larsen, M.D. (1998) A Simple Method of Sample Size Calculation for Linear and Logistic Regression. Statistical Methodology, 17, 1623-1634.<1623::AID-SIM871>3.0.CO;2-S

[17]   Hornemann, A., Kamischke, A., Luedders, D., Beyer, D., Deidrich, K. and Bohlmann, M. (2010) Advanced Age Is a Risk Factor for Higher Grade Perineal Lacerations during Delivery in Nulliparous Women. Archives of Gynecology and Obstetrics, 281, 59-64.

[18]   Gabbe, B.J., Bennell, K.L. and Finch, C.F. (2006) Why Are Older Australian Football Players at Greater Risk of Hamstring Injury? Journal of Science and Medicine in Sport, 9, 327-333.

[19]   Osterman, M. (2009) Birth Stats: Percentage of Mothers Receiving Epidural/Spinal Anesthesia by Age, Race, and Hispanic Origin of Mother: Total of 18 US Reporting Areas, Singletons Only, 2006. Birth, 36, 340-342.

[20]   Brancato, R.M., Church, S. and Stone, P.W. (2008) A Meta-Analysis of Passive Descent versus Immediate Pushing in Nulliparous Women with Epidural Analgesia in the Second Stage of Labor. Journal of Obstetric, Gynecologic, and Neonatal Nursing, 37, 4-12.

[21]   Hansen, S.L., Clark, S.L. and Foster, J.C. (2002) Active Pushing versus Passive Fetal Descent in the Second Stage of Labor: A Randomized Controlled Trial. Obstetrics and Gynecology, 99, 29-34.

[22]   Viswanathan, M., Hartmann, K., Palmieri, R., Lux, L., Swinson, T., Lohr, K.N., et al. (2005) The Use of Episiotomy in Obstetrical Care: A Systematic Review. Evidence Reports/Technology Assessments, No. 112. Agency for Healthcare Research and Quality, Rockville.

[23]   Spong, C., Berghella, V., Wenstrom, K., Mercer, B. and Saade, G. (2012) Preventing the First Cesarean Delivery Summary of a Joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, and American College of Obstetricians and Gynecologists Workshop. Obstetrics and Gynecology, 120, 1181-1193.