After Shoulder Dystocia: Managing the Subsequent Pregnancy and Delivery

After Shoulder Dystocia: Managing the Subsequent Pregnancy and Delivery

Edith D. Gurewitsch, MD,* † Tara L. Johnson, BS, BM, and Robert H. Allen, PhD

Among risk factors for shoulder dystocia, a prior history of delivery complicated by shoulder dystocia is the single greatest risk factor for shoulder dystocia occurrence, with odds ratios 7 to 10 times that of the general population. Recurrence rates have been reported to be as high as 16%. Whereas prevention of shoulder dystocia in the general population is neither feasible nor cost-effective, intervention efforts directed at the partic- ular subgroup of women with a prior history of shoulder dystocia can concentrate on potentially modifiable risk factors and individualized management strategies that can minimize recurrence and the associated significant morbidities and mortality. Semin Perinatol 31:185-195 © 2007 Elsevier Inc. All rights reserved.

KEYWORDS prior shoulder dystocia, history of shoulder dystocia, recurrence, brachial plexus palsy, injury prevention, risk management

T der dystocia recurrence, with odds ratios 7 to 10 times that of

he occurrence of shoulder dystocia is largely considered

unpredictable. Epidemiologically, although diabetics’ the general population. 8-10 Table 1 provides a summary of infants weighing more than 4 kg at birth are disproportion-

studies describing recurrence risks. 8-11 ately at higher risk for shoulder dystocia compared with av-

Unfortunately, the pathogenesis of shoulder dystocia is erage weight newborns, 1-5 nearly half of shoulder dystocia

multivariate, screening for “at-risk” individual pregnancies is events occur in nonmacrosomic infants of otherwise healthy

poorly predictive (positively or negatively) of its actual oc- women. 2,6 Although both antepartum and intrapartum risk

currence, and thus effective interventions for prevention are factors associated with occurrence of shoulder dystocia are

few. However, although avoidance of shoulder dystocia in known, 1,2 a substantial number of mother–infant pairs who

the general population is neither feasible nor cost-effec- actually experience shoulder dystocia during delivery have

tive, 12-14 concentrating intervention efforts on the particular none of these risk factors, whereas many more deliver un-

subgroup of women with a prior history of shoulder dystocia

has distinct merit. First, the occurrence of shoulder dystocia among risk factors for shoulder dystocia, a history of shoul-

eventfully despite having several risk factors. 7 However,

in a previous pregnancy indicates the need for a targeted der dystocia in a prior delivery carries a recurrence risk of

evaluation. Second, review of the details of a woman’s spe- 10% to 16%. 8-10 Akin to the single greatest predictor of pre-

cific shoulder dystocia experience can elucidate potentially term delivery being a history of preterm delivery in a previous

modifiable conditions and circumstances amenable to inter- pregnancy, a prior history of delivery complicated by shoul-

vention in a subsequent pregnancy. Third, even if shoulder der dystocia is indeed the single greatest risk factor for shoul-

dystocia recurs, complications may be minimized by individ- ualized management aimed at reducing or controlling those factors that predispose to significant morbidity and mortality

*Department of Gynecology and Obstetrics, Division of Maternal Fetal Med-

arising from shoulder dystocia. In focusing on the women

icine, The Johns Hopkins University School of Medicine, Baltimore, MD. †Department of Biomedical Engineering, The Johns Hopkins University

with a prior history of shoulder dystocia, this review will

School of Medicine, Baltimore, MD.

concentrate on those aspects of shoulder dystocia and injury

Some of the research reported in this review was funded by a grant from the

pathophysiology that are knowable and hence modifiable.

Centers for Disease Control’s National Center for Injury Prevention and

It is axiomatic that birth remains a moderately hazardous

Control: Grants for Traumatic Injury Biomechanics Research Program

process and that certain unintended and unavoidable out-

04047: #CE00433-03. The contents of the article are the sole opinions of the authors and do not represent the opinions of the NCIPC.

comes will occur even when complications are anticipated

Address reprint requests to Edith D. Gurewitsch, MD, The Johns Hopkins

and managed appropriately. Importantly, it is the untoward

Hospital, 600 North Wolfe Street, Phipps 217, Baltimore, MD 21287.

outcomes of the condition and not necessarily the condition

E-mail: egurewi@jhmi.edu

itself that we wish to prevent. Indeed, avoidance of shoulder

0146-0005/07/$-see front matter © 2007 Elsevier Inc. All rights reserved.

doi:10.1053/j.semperi.2007.03.009

186

E.D. Gurewitsch, T.L. Johnson, and R.H. Allen

dystocia recurrence per se should neither be expected nor set rior P

a Rate/ for Labor

as a goal. However, its outcome may be significantly im-

proved if those factors that increase the risk for harm are in

Rate of

prepared for and managed. As with any emergency, logical evidence-tested response to shoulder dystocia— either be-

fore it occurs or once in progress—is directly correlated with Dystocia

outcome, whether it occurs for the first time or is recurrent.

SD Failed

Cesarean

Unfortunately, fully tested and evidence-validated ap-

proaches to management specifically of the subsequent preg- Shoulder

nancy and delivery of a woman with a prior history of shoul- of

SD

der dystocia do not exist. Nevertheless, empiric modification

(RR) of

of delivery method or of intrapartum management for

women with a history of prior shoulder dystocia appears to History

SD

Rate Subjects of

be commonplace 8,10,11 ; however, without targeted emphasis

(RR-17) (RR-7) (RR-10) (RR-6.3)

on modifiable risk factors, such strategies have had little im-

pact on either recurrence or morbidity. 10,11 Our goal is to Recorded

propose a reasonable and logical approach to the management a

of a subsequent pregnancy and delivery after a shoulder dys-

tocia based on interpretation of the available literature. with

Among Recurrence

with

Recurrence Prevention

Women of

Starts Immediately After

SD Cesarean of

the Initial Shoulder Dystocia

Preventive strategies for the next possible shoulder dystocia

occurrence begin with the proper management of the after-

math of the index event. The incidence of shoulder dystocia is increasing. Among 1,15,16 for This may be due to better diagnoses, better documentation, or physical factors such as increasing birth

weight and obesity. The same is true for shoulder dystocia- Dystocia

Proportion

associated brachial plexus injury. 17 Fortunately, the majority

SD

of shoulder dystocia events are inconsequential in terms of untoward outcome. Still, up to 27% of shoulder dystocia will

Shoulder

Having after

be complicated by some maternal and/or fetal injury, with

significant proportion (up to 10%) having attendant perma- of

(%)

(25.1%) (13.5%) (12.1%) (20.2%)

N 18 nent sequelae. Whether the original shoulder dystocia

event was mild, moderate, or severe, the occurrence of shoul-

der dystocia at any delivery is worthy of documentation and

Proportion Pregnancy

evaluation.

Recurrence

Documentation

SD

risk.

Regardless of outcome, details of the shoulder dystocia— even

of

merely that it occurred—must be communicated to the mother Investigates

0.85% 2.0% 1.5% 1.9%

and, by way of documentation in the medical record, to the next that

Background Rate

relative

RR,

obstetrician who will care for her. Ideally, each participant in the delivery’s emergency response should author a note about the event itself and their role. However, there is no substitute for the

primary delivering clinician’s giving a comprehensive account- Literature

dystocia;

ing of each aspect of the management and its results. Items the

important to document are listed in Table 2 . of

Period)

(1993-2004)

(1993-1999) 11 shoulder

Acker proposed a shoulder dystocia intervention form 15

10 al.

(1980-1985) (1983-1992)

years ago that was in keeping with the idea that this degree of

(Time 8 9 al.

detail and documentation is not only important, but should be

standardized. Summary 19 et et The merits of documenting all of this informa-

1 Study

tion from risk management and medicolegal perspectives are reviewed elsewhere. 20-22 However, the relevance of such detail

Table Delivery

Smith, Lewis, Ginsberg, Gurewitsch,

Abbreviations:

to assessment of recurrence risk should not be underestimated.

Each aspect provides potential clues to the pathogenesis of that particular shoulder dystocia and, regardless of any retrospective assessment of the specific management’s propriety or prudence, thorough review of the precise sequence of events may identify potentially modifiable contributors to recurrence and outcome for that particular patient.