Anna L. Meenan, MD, Ina May Gaskin, MA, Pamela Hunt, and Charles A. Ball, MD

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The problem of shoulder dystocia has received increasing attention in the medical literature in recent years, probably
because of the tremendous potential for litigation that accompanies this disastrous complication. It has been estimated
that at least 8% of malpractice claims alleging fetal damage involve a birth complicated by shoulder dystocia
1. True shoulder dystocia has been defined as any birth in which maneuvers in addition tolateral traction and episiotomy
     are required to deliver the shoulders.
2  The reported incidence of shoulder dystocia ranges from 0.15% to 1.50% of allbirths,2-5 but the morbidity5-7 and
     mortality5 are high, with perinatal mortality ranging from 21 per 1000 to 290 per 1000, and morbidity rangingfrom
    16% to 48%. The most common fetal complications include asphyxia, seizures, brachial plexus palsy, and fractures of
    the humors and clavicle.8

Maternal risk factors have been studied extensively in an effort to predict and possibly prevent this complication
(Table 1).4 Numerous authors 2-4,9-11 have pointed out that shoulder dystocia occurs frequently in patients with few
or no risk factors. Even in women with more than one risk factor, the cost of preventing all, or even most, shoulder
dystocias would be prohibitive, both in dollars and in the number of cesarean sections performed.

Attention has thus been turned to techniques for managing a shoulder dystocia when it occurs. Several different
techniques have been proposed for freeing the impacted shoulders in this situation.l2 These have included lateral
traction in conjunction with fundal pressurc (sometimes condemned as ineffective and dangerous to both mother and
fetus),6,9,13-16 suprapubic pressure on the anterior shoulder, various rotational maneuvers involving either abduction
(Woods') or adduction (Rubin's) of the fetal shoulders, delivery of the posterior arm, intentional fracture of the clavicle,
and symphysiotomy.l2 Two recent additions to this list are the McRoberts maneuver.8 and the Zavanelli maneuver.12

The McRoberts maneuver, or hyperflexion of the mother's thighs onto her abdomen, is an elegantly simple maneuver that
releases the infant's impacted anterior shoulder and causes cephalad rotation of the mother's pubic bone and a subsequent
decrease in its angle of inclination. This maneuver has been reported to be quite successful, but may not work in all cases,
especially in those involving severe impaction of both shoulders. Because it is fast, simple, and can be done in any
situation, however, it should probably be the first maneuver attempted when gentle traction fails to deliver the shoulders.

The Zavanelli maneuver involves reversing the mechanism of delivery of the vertex by rotation to the occiput anterior
position and flexion of the head, returning it to the vagina with upward pressure, followed by immediate extraction of the
infant by emergency cesarean section. Of the nine shoulder dystocias known to have been managed this way so far,l7
one infant was stillborn, with resulting maternal sepsis and hysterectomy, one was bornwith an Apgar score of 1/4 but
is currently normal at age 7 years, and one currently has some degree of mental retardation.l7 The other six were
apparently delivered in healthy condition with no maternal or fetal complications. This maneuver is indeed a
revolutionary concept and will undoubtedly prove to be of value in rare cases of severe shoulder dystocia when used
as a method of last resort. It may have minimal applicability, however, to the situation of a family physician who
encounters a shoulder dystocia in a remote rural area without immediate access to obstetrical backup. In addition, the
Zavanelli maneuver involves an emergency procedure that is not without risks of its own. What childbirth attendants need
is a simple maneuver that can be performed quickly, with no special equipment or expertise, and that will result in the
prompt delivery of an uninjured infant with no maternal or fetal complications.

Table 1. Factors Predisposing to Shoulder Dystocia

Obesity
Multiparity
Postdates
Prior history of macrosomic infant
Midpelvic delivery
Prolonged 2nd stage
Macrosomia
Diabetes mellitus

Case Report

A 22-year-old woman, GIPO, presented to the labor and delivery unit at 41 weeks' gestation with ruptured membranes,
precipitous labor, and cervical dilation to an anterior rim. Her pregnancy had been uncomplicated except for obesity; she
weighed 255 l/2 pounds at admission. A 2-hour postprandial glucose at 29 weeks was 88 mg/dL (4.9 mmol/L). Her
fundal height was 40 cm the day before admission. The cervix quickly became completely dilated after admission, and
the vertex of the infant was born after 15 minutes of second stage labor, but the infant's anterior shoulder was not
deliverable by gentle traction. The McRoberts maneuver was tried without success, and as the patient was still in a labor
bed because of her precipitous labor, she was asked to get onto her hands and knees for delivery of the shoulders. This
she did with minimal assistance and surprising agility. Downward traction was then employed in an attempt to deliver the
posterior shoulder first, but this was also unsuccessful. A hand was then inserted into the vagina with the intent of
delivering the posterior arm, but at that moment the patient pushed again and the 8 Ib 11 oz (3940 g) male infant literally
squirted out onto the bed, over (or under, as it were) an intact perineum. The infant had no injuries and had an Apgar
score of 4/9 at 1 and 5 minutes. Total time from delivery of the head to completed delivery of the infant was estimated to
be less than 2 minutes.

Discussion

The inspiration for the use of the all-fours maneuver in this case, which was managed by the principal author, came from
aninformal article writtenby Ina May Gaskin on the results of a previously unpublished series of shoulder dystocias in
which the maneuver hadproven to be extremely effective.l8 This case series was accumulated by a group of direct-entry
midwives at the Farm Midwifery Center, Summertown,Tennessee, who learned the maneuver from Ms. Gaskin, director
of the birth center. She had, in turn, learned it from indigenous midwives while visiting the highlands of Guatemala in
1976. The midwives of the Farm Midwifery Center, with physician backup, operate a home birth service and
free-standing birth center, and have participated in a nationwide multicenter study of low-intervention birth practices and
outcomes.l9 From 1971 to the present, the midwives have attended 1750 births. Thirty-five of these were complicated by
shoulder dystocia, and all of them were managed by midwives  (Table 2). Three early births were managed with
traditional maneuvers, resulting in some birth injuries. The remaining 32 were managed by having the mother assume
the all-fours position, with no mortality, no birth injuries, and with excellent Apgar scores. All the babies for whom
follow-up was  possible (29 of 35) were developmentally normal (ages 9 months to 15 years). These statistics compare
favorably with the reported mortality rates of 21% to 29% and morbidity rates of 16% to 48%. In addition, despite
frequent  recommendations that any maneuvers to deliver the shoulders be preceded by a generous episiotomy or
proctoepisiotomy, 2 23 of the babies were delivered over an intact perineum, and there were no 3rd or 4th-degree
lacerations. Finally, though some authors recommend the time-consuming step of administering general anesthesia to
the mother before attempting alternative maneuvers,2 23 these babies were all delivered without anesthesia.

The incidence of shoulder dystocia in this series was 2.0% of all births, which is higher than the reported incidence, but
probably partially explained by the lower cesarean section rate of 1.45%, as an increase in cesarean section rate in any
series of births will lower the incidence ofshoulder dystocia as a percentage of all births. It might also be said that there
is a potential for over diagnosis of shoulder dystocia in any series of births, and that overdiagnosis of any condition
would result in adverse outcomes being diluted and favorable outcomes becoming more frequent. In the case of
shoulder dystocia, it is certainly true that the amount of lateral traction that a practitioner is willing to apply in attempting
to deliver the anterior shoulder before resorting to alternative maneuvers would significantly affect the frequency of
diagnosis, in addition to affecting the outcome for the baby. In *is series, however, the complete lack of morbidity and
mortality suggests that all of the cases that were indeed true shoulder dystocias had a favorable outcome, and that no
babies were harmed by unnecessary use of the maneuver.

The all-fours maneuver, described in George Engelmann's classic work, Labor Among Primitive Peoples,24 has been
mentioned only once, briefly, in recent medical literature, and promptly dismissed as not very likely to be useful.25 To
date there has been no documentation of the effectiveness ofthis technique in the mainstream medical literature, and
practitioners who have heard anecdotal reports of its usefulness have undoubtedly beenreluctant to try an unproven
maneuver, especially one that represents such a radical departure from the traditional approach to shoulder dystocia.

The explanation for the success of this maneuver probably lies in movement at the sacroiliac joints at term, which can
result in a l-cm to 2-cm increase in the sagittal diameter of the pelvic outlet.26 The lithotomy position restricts posterior
movement of the sacrum, while placing the mother on her hands and knees with weight evenly distributed over all four
extremities allows rotational movement around a transverse axis through the sacroiliac joints (Figure 1). Additional
benefit is probably obtained from the movement involved in the actual change of position, which may help to disimpact
the shoulders, and the addition of gravity to the forces tending to push the posterior shoulder anteriorly, allowing it to
slide over the sacral promontory. This would make it particularly useful in severe bilateral shoulder impactions. Indeed,
babies who were tightly wedged in the lithotomy position have been known to literally fall out of the vagina once this
position is assumed. This position is not to be confused with the knee-chest position, which has been mentioned in
recent texts,l6,27 although its effectiveness in treating shoulder dystocia has not been documented.

Critics of the all-fours position will claim such a change in position is time-consuming and difficult to accomplish,
precluding the use of other maneuvers. In the unlikely event that this maneuver is not successful, several other
suggested maneuvers can be performed in this position, including attempting to rotate either shoulder toward the
fetal back or chest, and attempting to deliver the posterior arm. Although delivery of the posterior arm in the lithotomy
position has been reported to be difficult in some cases because of inability to insert a hand into the vagina,7,l2,20 the
all-fours position offers the potential for increased space between the shoulder and the vaginal wall because of the
mobility of the sacrum and the fact that the weight of the maternal abdomen and fetus are not resting directly on the
posterior arm. In the case reported here, it is quite possible that the simple act of inserting a hand between the sacrum
and the posterior shoulder provided the leverage to lift the sacrum posteriorly and allow the baby to be born
spontaneously. Though fundal pressure and suprapubic pressure would be difficult if not impossible in this position,
they are not likely to be necessary or useful in attempts to deliver the posterior shoulder. Deliberate fracture of the
clavicle would be no more difficult in this position, and as a last resort even the Zavanelli maneuver can be performed
in this position.

It takes surprisingly little time (as little as 30 seconds) to get a patient to her hands and knees, even in the event of an
unexpected shoulder dystocia, such as the one reported here, and it can be accomplished even more quickly in a patient
with more than one known risk factor if the following precautions are taken in advance:

1. Encourage the mother to assume the all-fours position at intervals during labor. It is a very comfortable position,
especially when the baby is occiput posterior, and it is useful for facilitating rotation and descent. Admittedly, not all
mothers will be comfortable in this position, or it may be one of many different positions assumed by the patient
during the course of her labor, but it will help if she becomes familiar with this position in advance of the birth. Advise
her that it may become necessary to assume this position again for delivery of the shoulders.

2. Avoid intravenous lines. A heparin lock can provide emergency venous access without the restrictions of dangling
    IV lines.

3. For the same reason, avoid continuous electronic fetal monitoring equipment, or remove the belts as the vertex is
    delivered. Belts and cables are also restrictive, and studies have shown that auscultation of the fetal heart tones every
    5 minutes during the second stage of labor is sufficient.23,30

4. Along the same lines, avoid stirrups and extensive sterile drapes, and for obvious reasons, avoid epidural anesthesia.

5. Have at least two assistants present at the birth. Labor coaches can be helpful in facilitating rapid changes in position
     if necessary.

6. Finally, deliver the baby in a bed, not on a narrow delivery table. Consider using the lateral decubitus position, or
    better yet, complete the entire delivery in the all-fours position in those patients at high risk for a shoulder dystocia
 

Admittedly, these recommendations run counter to the whole technological approach to childbirth that has been
developed over the past 20 years, and they are not likely to be adopted in large traditional centers. Although anecdotal
reports indicate the maneuver has been used successfully in high-tech settings,l8 we expect it to prove most useful in the
context of the low-intervention approach to obstetrics that is most familiar to family physicians.

Clearly, maintaining a high level of alertness to this problem and avoiding panic when shoulder dystocia is encountered
will prevent the obstetrical disasters that occur when excessive fundal pressure and lateral traction are used in desperation
by unprepared birth attendants. An orderly plan of management, which should be initiated as soon as shoulder dystocia
is suspected, would include a quick McRoberts maneuver, followed immediately by the all-fours position and an attempt
to deliver the posterior shoulder first by gentle downward traction and, failing that, the posterior arm, by flexing it at the
elbow and drawing it out across the fetal chest and face. Use of this maneuver appears to be a safe and costeffective way
of dealing with shoulder dystocia for all birth attendants, but particularly for those who practice in rural areas.

Acknowledgment

An instructional program showing an actual shoulder dystocia delivery in the all-fours position is available. For more
information, write to:

Video, Farm Midwifery Center, 12, The Farm, Summertown, TN 38483.

References

1. Ifiy L, Goldsmith LS. Obstetric background of malpractice claims involving fetal damage. Second Perinatal Practice
    and Malpractice Symposium. New York: Healthmark Communications, 1985: 95.

2. Resnick R. Management of shoulder girdle dystocia. Clin Obstet Gynecol 1980; 23:559.

3. Gross TL, Sokol RJ, Williams T, et al. Shoulder dystocia: a fetal-physician risk. Am J Obstet Gynecol 1987;
   156:1408.

4. Lee CY. Shoulder dystocia. Clin Obstet Gynecol 1987, 30:77.

5 . 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.

6. Gross SJ, Shime J, Farine D. Shoulder dystocia. Predictors and outcome. A five-year review. Am J Obstet Gynecol
   1987; 156: 334.

7. McCall JD. Shoulder dystocia: a study of after effects. Am J Obstet Gynecol 1962; 83:1486.

8. Gonick B, Stringer CA, Held B. An alternative maneuver for the management of shoulder dystocia.
    Am J Obstet Gynecol 983; 145:882.

9. Smeltzer JS. Prevention and management of shoulder dystocia. Clin Obstet Gynecol 1986, 29:299.

10. Acker DB, Sach BP, Friedman EA. Risk factors for shoulder dystocia in the average weight infant. Obstet Gynecol
     1986; 67:

11. Deter RL, Hadlock FP. Use of ultrasound in the detection of macrosomia: a review. J Clin Ultrasound 1985, 13:519.

12. Sandberg EC. The Zavanelli maneuver: a potentially revolutionary method for the resolution of shoulder dystocia.
      Am J Obstet Gynecol 1985; 52:479.
13. Chez RA, Benedetti TJ. How to manage shoulder dystocia during delivery. Contemp Obstet Gynecol 1982, 19:203.

14. Swartz DP. Shoulder girdle dystocia in vertex delivery. Obstet Gynecol 1960; 15:194.

15. Dignam WJ. Difficulties in delivery, including shoulder dystocia and malpresentation of the fetus.
      Clin Obstet Gynecol 976;

16. Gabbe SG, Neibyl JR, Simpson JL. Obstetrics: normal and problsm pregnancies. New York: Churchill Livingstone,
     1986:479-80.

17. Sandberg EC. The Zavanelli maneuver extended: progression of a revolutionary concept. Arn J Obstet Gynecol 1988;
     158:1347.

18. Gaskin IM. Shoulder dystocia: controversies in management. Birth Gazette 1988; 5:14.

19. Rooks JP, Weatherby NL, Emst EKM, et al. Outcome of care in birth centers: the National Birth Center study.
      N Engl J Med 1989; 321:1804.

20. Rubin A. Management of shoulder dystocia. JAMA 1964; 189:

21. Schwartz BC, Dixon DM. Shoulder dystocia. Obstet Gynecol 1958; 11:468.

22. O'Leary JA, Leonetti HB. Shoulder dystocia: prevention and treatment. Am J Obstet Gynecol 1990, 162:5.

23. Benedetti TJ. Managing shoulder dystocia. Contemp Obstet Gynecol 1979; 14:33.

24. Englemann G. Labor among prirnitive peoples. 2nd ed. St Louis: JH Cambers and Co, 1883:56.

25. Baird J. More on shoulder dystocla [Letter]. Contemp Obstet Gynecol 1982, 20:19.

26. Borell U, Femstrom I. A pelvimetric method for the assessment of pelvic 'mouldability'. Acta Radiol 1957a; 47:365.

27. Varney H. Nurse-Midwifery. 2nd ed. Boston: Blackwell Scientific Publications, 1987:348.

28. Haverkamp AD, Thompson HE, McFee JC, et al. The evaluation of continuous fetal heart rate monitoring in high
      risk pregnancy. Am J Obstet Gynecol 1978, 125:310-20.

29. Haverkarnp AD, Orleans M, Langedoerfer S, et al. A controlled trial of the differential effects of intrapartum fetal
      monitoring. Am J Obstet Gynecol 1979, 134:399-412.

30. Luthy D, Shy D, VanBelle G, et al. A randomized trial of electronic fetal monitoring in pretemn labor.
      Obstet Gynecol 69:687.

Some related works available on-line:

   * The Boots at The Door
   * Insurance Industry Kills Health Care Reform
   * Bibliography of Midwifery
   * Interview with Ina May Gaskin
   * The Mother of Midwifery

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