Shoulder dystocia: definitions and incidence.

Area of Science:

• Obstetrics and Gynecology
• Perinatal Medicine

Background:

• Shoulder dystocia is defined as the need for additional obstetric maneuvers when initial gentle traction fails.
• Existing guidelines from the American College of Obstetricians and Gynecologists and the Royal College of Obstetricians and Gynaecologists agree on this definition.

Purpose of the Study:

• To analyze the incidence and risk factors associated with shoulder dystocia.
• To highlight disparities in shoulder dystocia rates based on maternal and delivery characteristics.

Main Methods:

• Review of obstetric practice bulletins and guidelines.
• Analysis of shoulder dystocia rates based on maternal diabetes status, mode of delivery (spontaneous vs. assisted), and birthweight.
• Comparison of incidence rates between the US and other countries.

Main Results:

• The overall rate of shoulder dystocia is 1.4% (0.7% for vaginal births).
• Diabetic mothers have a 201% higher rate (1.9%) compared to non-diabetics (0.6%).
• Assisted vaginal deliveries (vacuum/forceps) show a 254% higher likelihood (2.0%) versus spontaneous births (0.6%).
• Birthweight and geographical location influence shoulder dystocia likelihood.

Conclusions:

• Shoulder dystocia is a significant obstetric complication with identifiable risk factors.
• Further research should aim to decrease shoulder dystocia rates and associated morbidities without increasing cesarean delivery rates.