Consult the medical resource doctors trust

UpToDate is one of the most respected medical information resources in the world, used by over 360,000 doctors and thousands of patients to find answers to medical questions.

  • Content written by a faculty of over 4,000 physicians from leading medical institutions
  • Unbiased: free of advertising or pharmaceutical funding
  • Evidence-based treatment recommendations
  • Continuously updated to incorporate new medical findings

Diagnosis and management of pregnancies at risk for shoulder dystocia

INTRODUCTION

Shoulder dystocia is best defined as the need for additional obstetric maneuvers to effect delivery of the fetal shoulders at the time of vaginal delivery. It occurs in 0.2 to 3 percent of all births and represents an obstetric emergency [1]. Shoulder dystocias can be anticipated only rarely, as many occur in the absence of identifiable risk factors. Therefore, all obstetric care providers must be prepared to recognize a shoulder dystocia immediately and proceed through an orderly sequence of steps to effect delivery in a timely manner and minimize risk to the mother and fetus. It should be noted, however, that permanent birth injury, and even fetal death, can result in cases of shoulder dystocia that are appropriately identified and managed.

Risk factors for shoulder dystocia and management of pregnancies at risk will be discussed here. Diagnosis and intrapartum management of shoulder dystocia are reviewed separately. (See "Intrapartum management and outcome of shoulder dystocia".)

RISK FACTORS

High birth weight is a major risk factor for shoulder dystocia. Several other factors have also been associated with shoulder dystocia, although many of these are related to high birth weight.

Fetal macrosomia — Studies have consistently shown that macrosomia is a major risk factor for shoulder dystocia [2,3]. Fetal macrosomia is best defined as an estimated fetal weight (EFW) of greater than or equal to 4500 grams, as morbidity and mortality increase above this level [4,5]. The overall prevalence of birth weight over 4000 grams in the general obstetric population of the United States is 10 percent [6], but falls to 1.5 percent for birth weight over 4500 grams [4]. Risk factors for macrosomia are listed in the table (table 1).

The relationship between fetal/newborn size and shoulder dystocia is illustrated by the following examples:
To continue reading this article you need to subscribe.

Read the rest of this article and others like it

The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use (click here) ©2009 UpToDate, Inc.
References Top
  1. ACOG practice bulletin clinical management guidelines for obstetrician-gynecologists. Shoulder dystocia. Number 40, November 2002. Obstet Gynecol 2002; 100:1045.
  2. Dildy, GA, Clark, SL. Shoulder dystocia: Risk identification. Clin Obstet Gynecol 2000; 43:265.
  3. Nesbitt, TS, Gilbert, WM, Herrchen, B. Shoulder dystocia and associated risk factors with macrosomic infants born in California. Am J Obstet Gynecol 1998; 179:476.
  4. Boulet, SL, Alexander, GR, Salihu, H, Pass, M. Macrosomic births in the United States: Determinants, outcome, and proposed grades of risk. Am J Obstet Gynecol 2003; 188:1372.
  5. Zhang, X, Decker, A, Platt, RW, Kramer, MS. How big is too big? The perinatal consequences of fetal macrosomia. Am J Obstet Gynecol 2008; 198:517.
  6. Ventura, SJ, Bachrach, CA. Nonmarital childbearing in the United States, 1940-99. Natl Vital Stat Rep 2000; 48:1.
  7. Overland, EA, Spydslaug, A, Nielsen, CS, Eskild, A. Risk of shoulder dystocia in second delivery: does a history of shoulder dystocia matter?. Am J Obstet Gynecol 2009; 200:506.
  8. Langer, O, Berkus, MD, Huff, RW, Samueloff, A. Shoulder dystocia: Should the fetus weighing greater than or equal to 4000 grams be delivered by cesarean section? Am J Obstet Gynecol 1991; 165:831.
  9. Chauhan, SP, Grobman, WA, Gherman, RA, et al. Suspicion and treatment of the macrosomic fetus: A review. Am J Obstet Gynecol 2005; 193:332.
  10. Mahony, R, Walsh, C, Foley, ME, et al. Outcome of second delivery after prior macrosomic infant in women with normal glucose tolerance. Obstet Gynecol 2006; 107:857.
  11. Modanlou, HD, Komatsu, G, Dorchester, W, et al. Large-for-gestational-age neonates: Anthropometric reasons for shoulder dystocia. Obstet Gynecol 1982; 60:417.
  12. McFarland, MB, Trylovich, CG, Langer, O. Anthropometric differences in macrosomic infants of diabetic and nondiabetic mothers. J Matern Fetal Med 1998; 7:292.
  13. Bofill, JA, Rust, OA, Devidas, M, et al. Shoulder dystocia and operative vaginal delivery. J Matern Fetal Med 1997; 6:220.
  14. Demissie, K, Rhoads, GG, Smulian, JC, et al. Operative vaginal delivery and neonatal and infant adverse outcomes: population based retrospective analysis. BMJ 2004; 329:24.
  15. Caughey, AB, Sandberg, PL, Zlatnik, MG, et al. Forceps compared with vacuum: rates of neonatal and maternal morbidity. Obstet Gynecol 2005; 106:908.
  16. Cheng, YW, Norwitz, ER, Caughey, AB. The relationship of fetal position and ethnicity with shoulder dystocia and birth injury. Am J Obstet Gynecol 2006; 195:856.
  17. Benedetti, TJ, Gabbe, SG. Shoulder dystocia. A complication of fetal macrosomia and prolonged second stage of labor with midpelvic delivery. Obstet Gynecol 1978; 52:526.
  18. Gherman, RB, Chauhan, S, Ouzounian, JG, et al. Shoulder dystocia: the unpreventable obstetric emergency with empiric management guidelines. Am J Obstet Gynecol 2006; 195:657.
  19. Lewis, DF, Raymond, RC, Perkins, MB, et al. Recurrence rate of shoulder dystocia. Am J Obstet Gynecol 1995; 172:1369.
  20. Ginsberg, NA, Moisidis, C. How to predict recurrent shoulder dystocia. Am J Obstet Gynecol 2001; 184:1427.
  21. Baskett, TF, Allen, AC. Perinatal implications of shoulder dystocia. Obstet Gynecol 1995; 86:14.
  22. Moore, HM, Reed, SD, Batra, M, Schiff, MA. Risk factors for recurrent shoulder dystocia, Washington state, 1987-2004. Am J Obstet Gynecol 2008; 198:e16.
  23. Usta, IM, Hayek, S, Yahya, F, et al. Shoulder dystocia: what is the risk of recurrence?. Acta Obstet Gynecol Scand 2008; 87:992.
  24. Smith, RB, Lane, C, Pearson, JF. Shoulder dystocia: what happens at the next delivery?. Br J Obstet Gynaecol 1994; 101:713.
  25. Gemer, O, Bergman, M, Segal, S. Labor abnormalities as a risk factor for shoulder dystocia. Acta Obstet Gynecol Scand 1999; 78:735.
  26. Acker, DB, Gregory, KD, Sachs, BP, Friedman, EA. Risk factors for Erb-Duchenne palsy. Obstet Gynecol 1988; 71:389.
  27. Poggi, SH, Stallings, SP, Ghidini, A, et al. Intrapartum risk factors for permanent brachial plexus injury. Am J Obstet Gynecol 2003; 189:725.
  28. Mehta, SH, Bujold, E, Blackwell, SC, et al. Is abnormal labor associated with shoulder dystocia in nulliparous women?. Am J Obstet Gynecol 2004; 190:1604.
  29. Acker, DB, Sachs, BP, Friedman, EA. Risk factors for shoulder dystocia in the average-weight infant. Obstet Gynecol 1986; 67:614.
  30. McFarland, M, Hod, M, Piper, JM, et al. Are labor abnormalities more common in shoulder dystocia?. Am J Obstet Gynecol 1995; 173:1211.
  31. Lurie, S, Levy, R, Ben-Arie, A, Hagay, Z. Shoulder dystocia: could it be deduced from the labor partogram?. Am J Perinatol 1995; 12:61.
  32. Acker, DB, Sachs, BP, Friedman, EA. Risk factors for shoulder dystocia. Obstet Gynecol 1985; 66:762.
  33. Campbell, MK, Ostbye, T, Irgens, LM. Post-term birth: Risk factors and outcomes in a 10-year cohort of Norwegian births. Obstet Gynecol 1997; 89:543.
  34. Geary, M, McParland, P, Johnson, H, Stronge, J. Shoulder dystocia--is it predictable?. Eur J Obstet Gynecol Reprod Biol 1995; 62:15.
  35. Hassan, AA. Shoulder dystocia: Risk factors and prevention. Aust N Z J Obstet Gynaecol 1988; 28:107.
  36. Sama, JC, Iffy, L. Maternal weight and fetal injury at birth: data deriving from medico-legal research. Med Law 1998; 17:61.
  37. Hope, P, Breslin, S, Lamont, L, et al. Fatal shoulder dystocia: a review of 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy. Br J Obstet Gynaecol 1998; 105:1256.
  38. Perlow, JH, Morgan, MA, Montgomery, D, Towers, CV, Porto, M. Perinatal outcome in pregnancy complicated by massive obesity. Am J Obstet Gynecol 1992; 167:958.
  39. Robinson, H, Tkatch, S, Mayes, DC, et al. Is maternal obesity a predictor of shoulder dystocia?. Obstet Gynecol 2003; 101:24.
  40. Bahar, AM. Risk factors and fetal outcome in cases of shoulder dystocia compared with normal deliveries of a similar birthweight. Br J Obstet Gynaecol 1996; 103:868.
  41. Gudmundsson, S, Henningsson, AC, Lindqvist, P. Correlation of birth injury with maternal height and birthweight. BJOG 2005; 112:764.
  42. Seigworth, GR. Shoulder dystocia. Review of 5 years' experience. Obstet Gynecol 1966; 28:764.
  43. Kitzmiller, JL, Mall, JC, Gin, GD, et al. Measurement of fetal shoulder width with computed tomography in diabetic women. Obstet Gynecol 1987; 70:941.
  44. Verspyck, E, Goffinet, F, Hellot, MF, et al. Newborn shoulder width: a prospective study of 2222 consecutive measurements. Br J Obstet Gynaecol 1999; 106:589.
  45. Cohen, BF, Penning, S, Ansley, D, et al. The incidence and severity of shoulder dystocia correlates with a sonographic measurement of asymmetry in patients with diabetes. Am J Perinatol 1999; 16:197.
  46. Klaij, FA, Geirsson, RT, Nielsen, H, et al. Humerospinous distance measurements: accuracy and usefulness for predicting shoulder dystocia in delivery at term. Ultrasound Obstet Gynecol 1998; 12:115.
  47. Ouzounian, JG, Gherman, RB. Shoulder dystocia: are historic risk factors reliable predictors?. Am J Obstet Gynecol 2005; 192:1933.
  48. Athukorala, C, Middleton, P, Crowther, CA. Intrapartum interventions for preventing shoulder dystocia. Cochrane Database Syst Rev 2006; :CD005543.
  49. Gonen, R, Bader, D, Ajami, M. Effects of a policy of elective cesarean delivery in cases of suspected fetal macrosomia on the incidence of brachial plexus injury and the rate of cesarean delivery. Am J Obstet Gynecol 2000; 183:1296.
  50. Sacks, DA, Chen, W. Estimating fetal weight in the management of macrosomia. Obstet Gynecol Surv 2000; 55:229.
  51. Rouse, DJ, Owen, J, Goldenberg, RL, Cliver, SP. The effectiveness and costs of elective cesarean delivery for fetal macrosomia diagnosed by ultrasound. JAMA 1996; 276:1480.
  52. Rouse, DJ, Owen, J. Prophylactic cesarean delivery for fetal macrosomia diagnosed by means of ultrasonography--A Faustian bargain?. Am J Obstet Gynecol 1999; 181:332.
  53. Weeks, JW, Pitman, T, Spinnato JA, 2nd. Fetal macrosomia: does antenatal prediction affect delivery route and birth outcome?. Am J Obstet Gynecol 1995; 173:1215.
  54. Weiner, Z, Ben-Shlomo, I, Beck-Fruchter, R, et al. Clinical and ultrasonographic weight estimation in large for gestational age fetus. Eur J Obstet Gynecol Reprod Biol 2002; 105:20.
  55. Boulet, SL, Alexander, GR, Salihu, HM. Secular trends in cesarean delivery rates among macrosomic deliveries in the United States, 1989 to 2002. J Perinatol 2005; 25:569.
  56. Sanchez-Ramos, L, Bernstein, S, Kaunitz, AM. Expectant management versus labor induction for suspected fetal macrosomia: a systematic review. Obstet Gynecol 2002; 100:997.
  57. Irion, O, Boulvain, M. Induction of labour for suspected fetal macrosomia. Cochrane Database Syst Rev 2000; :CD000938.
white circle LOG IN
white circle DEMO