Dystocia is a term used to describe the difficult delivery of a baby. In shoulder dystocia, the baby's head can be delivered, but the shoulders cannot pass through the birth canal. The shoulders are too wide to fit and become lodged behind the mother's pubic bone or the opening of the birth canal.
Typically, babies born with shoulder dystocia do not suffer long-term complications. If complications do occur, they are usually because the baby has become stuck too long in the birth canal.
For the baby:
- Lack of oxygen
- Broken arm or collarbone
- Arm nerve damage
For the mother:
- Tearing or bruising of the cervix, rectum, or vagina
- Bruising to the bladder
There are a variety of reasons why a baby's shoulders may become lodged during delivery. The most common reasons include:
- Delivering large babies with unusually high birth weights. This is is most often caused by diabetes or mothers who are overweight.
- Mother's pelvic opening being too small to allow the baby's shoulders to fit
Factors that may increase your baby's chance of shoulder dystocia include:
- Maternal diabetes
- Mothers who are significantly overweight
- Mothers of small stature may also have a small pelvic structure
- A baby who is very large
Signs and Symptoms
The signs of shoulder dystocia are noticeable when the baby's head is delivered. The delivery does not progress because the baby's shoulders are lodged in the birth canal behind the mother's pubic bone.
Shoulder dystocia cannot be diagnosed until it occurs during delivery. It can sometimes be predicted by determining the weight and size of the fetus and the structure of the mother's pelvis. This information can help determine whether a vaginal delivery is safe for the mother and baby. An ultrasound may be done prior to labor to determine if the baby is too large to fit safely through the birth canal during delivery.
After shoulder dystocia is diagnosed, the doctor will go through a series of maneuvers to attempt to dislodge the baby's shoulder and allow for a vaginal delivery. Options include:
- Manipulated vaginal delivery—There are a variety of maneuvers that the doctor can do to help the mother deliver the baby vaginally.
- Cesarean section (C-section)—If the maneuvers do not work, the baby will need to be delivered via an emergency C-section. For babies who are at risk of shoulder dystocia because of their large size, a C-section may be scheduled.
Shoulder dystocia cannot be prevented. Babies who are at risk of shoulder dystocia because of large size can be evaluated prior to delivery with regular prenatal care and ultrasound testing. Women with diabetes or who are very overweight should have the size of their babies estimated. Women with pregnancies complicated by a large fetus are at risk for shoulder dystocia and should be counseled about the option of delivery by C-section.
- Reviewer: EBSCO Medical Review Board Beverly Siegal, MD, FACOG
- Review Date: 09/2017 -
- Update Date: 09/30/2013 -