[Epidemiology of shoulder dystocia].

Abstract

OBJECTIVES:

To synthetize the available evidence regarding the incidence and risk factors of shoulder dystocia (SD).

METHODS:

Consultation of the Medline database, and of national guidelines.

RESULTS:

Shoulder dystocia is defined as a vaginal delivery that requires additional obstetric manoeuvres to deliver the foetus after the head has delivered and gentle traction has failed. With this definition, the incidence of SD in population-based studies is about 0.5-1% of vaginal deliveries. Many risk factors have been described but most associations are not independent, or have not been constantly found. The 2 characteristics consistently found as independent risk factors for SD in the literature are previous SD (incidence of SD of about 10% in parturients with previous SD) and foetal macrosomia. Maternal diabetes and obesity also are associated with a higher risk of SD (2 to 4 folds) but these associations may be completely explained by foetal macrosomia. However, even factors independently and constantly associated with SD do not allow a valid prediction of SD because they are not discriminant; 50 to 70% of SD cases occur in their absence, and the great majority of deliveries when they are present is not associated with SD.

CONCLUSION:

Shoulder dystocia is defined by the need for additional obstetric manoeuvres to deliver the foetus after the head has delivered and gentle traction has failed, and complicates 0.5-1% of vaginal deliveries. Its main risk factors are previous SD and macrosomia, but they are poorly predictive. SD remains a non-predictable obstetrics emergency. Knowledge of SD risk factors should increase the vigilance of clinicians in at-risk contexts.

• Authors: C Deneux-Tharaux, P Delorme
• Journal: Journal de gynecologie, obstetrique et biologie de la reproduction (J Gynecol Obstet Biol Reprod (Paris)) Vol. 44 Issue 10 Pg. 1234-47 (Dec 2015) ISSN: 1773-0430 [Electronic] France
• Vernacular Title: Épidémiologie de la dystocie des épaules.
• PMID: 26527012 (Publication Type: English Abstract, Journal Article, Review)
• Copyright: Copyright © 2015. Published by Elsevier Masson SAS.

Topics

• Birth Injuries (epidemiology)
• Delivery, Obstetric (adverse effects, statistics & numerical data)
• Dystocia (epidemiology, therapy)
• Female
• Fetal Macrosomia (complications, epidemiology)
• Humans
• Incidence
• Infant, Newborn
• Pregnancy
• Risk Factors
• Shoulder