Shoulder dystocia is a life-threatening emergency that occurs during delivery when a baby’s shoulder becomes stuck in the birth canal after the head has emerged. The baby’s shoulder usually becomes stuck behind the mother’s pelvic bone. Brain injury or death can occur when the umbilical cord is compressed and the baby suffers from asphyxia or hypoxia. There can be significant complications for the mother as well, such as post-partum hemorrhage, rectovaginal fistula, or rupture of the uterus.
Risk Factors and Complications
Although shoulder dystocia is difficult to predict and can appear without warning, there are well-recognized risk factors, such as diabetes, fetal macrosomia, and maternal obesity.
Other risk factors include:
- Maternal short stature or petite frame
- Previous shoulder dystocia delivery
- Post due-date delivery
- Larger-than-average fetus
- Forceps or vacuum delivery
- Extended labor period
- Breech deliveries
Complications that can arise from shoulder dystocia are:
- Brachial plexus palsy (Erb’s palsy or Klumpke’s palsy)
- Clavicle fracture
- Fetal hypoxia and death
- Permanent brain damage
- Humerus fracture
When one or more of these risk factors are present, the delivery team should be prepared for shoulder dystocia and ready to perform the necessary intervention(s). If shoulder dystocia is highly suspected, a scheduled C-section may be the safest course of action. A pre-birth ultrasound can also reveal if the baby is too large to pass easily through the pelvic bones. There are vaginal delivery methods that can be utilized to lessen the chance of complications, including the “head and shoulder method,” where the doctor doesn’t pause after the head is delivered and instead continues with the downward momentum of the baby until her shoulders are present.
Once shoulder dystocia is discovered, timely intervention is the key to delivering a healthy baby. There are a series of well-known maneuvers used by doctors to dislodge the baby’s shoulder and allow for a vaginal delivery. The alternative to these maneuvers is to perform an immediate C-section.
Williams Obstetrics 23rd Ed.
New England Journal of Medicine Vol. 352, No. 24, pp. 2477-2485
T. Russell – J. Tolliver, M.D.