Dra. Ivone Lobo

Obstetrician Gynaecologist · Sub specialist in Maternal Fetal Medicine
Director of the Gynecology & Obstetrics Unit

Shoulder dystocia

An obstetric emergency

HPA Magazine 19

Shoulder Dystocia (SD) is one of the most feared and stressful situations in an Obstetric Emergency. This can occur during a vaginal delivery, when additional obstetric maneuvers are required for foetal extraction after expulsion of the foetal head.
It is important for the obstetric team to be aware of the risk factors that contribute to SD; what are the complications; how to reach a diagnosis; and what interventions are needed to provide the patient with the best care possible, before, during, and after delivery.
Regular team training on SD is therefone of the utmost importantce.  The term dystocia comes from the Greek, where “dys” means difficult and “tokos” means childbirth.

In SD, the fetal shoulders cannot progress beyond the maternal pubic bone, causing the interval between expulsion of the fetal head and body to exceed 60 seconds.
Although there are several risk factors: mother (lower and smaller pelvis, diabetes, obesity, exaggerated weight gain, previous macrosomic fetus or previous SD); foetus (foetal macrosomia); (prolonged second stage or abnormal progression of labour), these have a low positive predictive value alone or in combination to permit  in most cases the prevention of SD. 
There is a variation in the incidence of SD of 0.2% and 3% of the total deliveries. 
The main priorities in SD are to avoid maternal or foetal injury during childbirth.
Foetal death is a possible and more serious outcome. Brachial plexus injury is the most important complication of SD, causing a 2.3% to 16% complication in deliveries where this occurs. Most brachial plexus injuries are solved without permanent disability, but about 10% result in permanent neurologic dysfunction.
There is an increase in maternal morbidity particularly postpartum hemorrhage (11%) and 3rd and 4th degree perineal lacerations (3.8%).
There can be significant neonatal morbidity and mortality even when treated correctly.
It is important that the obstetric team quickly recognize the SD, stay calm, ask for help and have a systematic approach in order to minimize maternal and fetal complications.
To make sure the team is prepared should a situation arise, we regularly carry out training sessions on SD, consisting of theory and practical simulators. The last one was held on the 28th of October 2022. 
Specialists should be aware of the risk factors associated with women in labor and always remain alert to the possibility of developing Shoulder Dystocia.