Population-Based Risk Factors for Shoulder Dystocia

To re-examine the risk factors for shoulder dystocia given the increasing rates of obesity and diabetes in pregnant women.

Retrospective observational study.

Five hospitals located in Wisconsin, Florida, Maryland, Michigan, and Alabama.

We evaluated 19,236 births that occurred between April 1, 2011, and July 25, 2013.

Data were collected from electronic medical records and used to evaluate the risk of shoulder dystocia. Data were analyzed using a generalized linear mixed model, which controlled for clustering due to site.

When insulin was prescribed, gestational diabetes was associated with an increased risk of shoulder dystocia (odds ratio = 2.10, 95% confidence interval [1.01, 4.37]); however, no similar association was found with regard to gestational diabetes treated with glycemic agents or through diet. Use of epidural anesthesia was associated with an increased risk for shoulder dystocia (odds ratio = 3.47, 95% confidence interval [2.72, 4.42]). Being Black or Hispanic, being covered by Medicaid or having no insurance, infant gestational age of 41 weeks or greater, and chronic diabetes were other significant risk factors.

With the changing characteristics of pregnant women, labor and birth clinicians care for more pregnant women who have an increased risk for shoulder dystocia. Our findings may help prospectively identify women with the greatest risk.