Objective definition of shoulder dystocia: A prospective evaluation,☆☆,,★★

Presented at the Eighteenth Annual Meeting of the Society of Perinatal Obstetricians, Miami, Florida, February 2-7, 1998.
https://doi.org/10.1016/S0002-9378(98)70191-7Get rights and content

Abstract

Objective: The current study was undertaken to validate the objective definition of shoulder dystocia in a prospectively evaluated group of patients. Study Design: Selected vaginal deliveries from January 1995 to December 1996 (n = 722) were evaluated for head-to-body delivery time and use of ancillary obstetric maneuvers. Charts were reviewed for perinatal and outcome data. Results: Ninety-nine deliveries were complicated by shoulder dystocia and 623 deliveries had no shoulder dystocia. The objective definition described infants with lower 1-minute Apgar scores and increased birth weight. All fetal injuries were in the shoulder dystocia group. Duration of the second stage was significantly associated with a diagnosis of shoulder dystocia. The risk of shoulder dystocia was increased with maternal diabetes, but it was not correlated with birth weight in diabetics. Conclusions: The objective definition of shoulder dystocia identified a group of patients with an increased birth weight and risk of fetal injuries. The use of an objective definition will assist the evaluation of prophylactic and treatment proposals for shoulder dystocia. (Am J Obstet Gynecol 1998;179:934-7.)

Section snippets

Material and methods

The study was performed at Harbor–University of California, Los Angeles, Medical Center in Torrance, California, during 1995 and 1996. The study was approved by the Human Subjects Protection Committee of Harbor–University of California, Los Angeles, Medical Center. Nursing staff in the labor and delivery unit were instructed to record head-to-body time for vaginal vertex deliveries. Nursing staff and the delivery attendant also recorded the use of ancillary obstetric maneuvers. During this time

Results

Seven hundred twenty-two deliveries were timed and recorded between September 1995 and August 1996. During this time there were a total of 2235 deliveries on the obstetrics unit. Ninety-nine deliveries were complicated by shoulder dystocia, as defined objectively. Among these 99 deliveries, 46 were completed with the assistance of ancillary obstetric maneuvers and 72 had head-to-body times ≥60 seconds. Only 25% of objectively defined shoulder dystocia deliveries were subjectively identified by

Comment

We elected to develop an objective definition for shoulder dystocia because research on the prediction, prevention, and management of shoulder dystocia is difficult because of the lack of a standard definition. In our original report we quantified the time intervals for all events of vertex vaginal delivery from crowning to delivery of the placenta. We found that a head-to-body time interval of ≥60 seconds was 2 SDs above the mean and described a subpopulation with a significantly increased

Acknowledgements

We thank the Perinatal Clinical Research Nurses for technical support.

References (11)

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From the Division of Obstetrics, Department of Obstetrics and Gynecology, Harbor–University of California, Los Angeles, Medical Center.

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Supported in part by General Clinical Research Center grant No. MO1-RR00425 from the National Centers for Research Resources, National Institutes of Health.

Reprint requests: Marie Beall, MD, Harbor–University of California, Los Angeles, Medical Center, Department of Obstetrics and Gynecology, Box 3, 1000 W Carson St, Torrance, CA 90509.

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