Last Updated on February 1, 2025 by Michelle Wan
Shoulder dystocia is a serious childbirth complication that occurs when a baby’s shoulders become stuck behind the mother’s pelvic bone after the head has been delivered. This condition requires immediate medical intervention, as prolonged delays can lead to birth injuries, such as nerve damage, fractures, oxygen deprivation, or cerebral palsy.
While shoulder dystocia can happen unexpectedly, certain risk factors and medical conditions increase the likelihood of its occurrence. In this detailed blog, we will discuss what causes shoulder dystocia, the risk factors involved, and how healthcare providers can manage this complication to prevent injuries.
Understanding Shoulder Dystocia
During a normal vaginal delivery, the baby’s head, shoulders, and body pass smoothly through the birth canal. However, in cases of shoulder dystocia, the baby’s anterior shoulder (the one closest to the mother’s pubic bone) gets trapped behind the pelvic bone, preventing the rest of the body from being delivered easily.
If this condition is not resolved quickly, it can cause:
✔ Oxygen deprivation (hypoxia), leading to brain damage.
✔ Brachial plexus injuries, such as Erb’s palsy or Klumpke’s palsy.
✔ Fractured collarbone or humerus.
✔ Severe maternal complications, including postpartum hemorrhage and perineal tearing.
Understanding the causes and risk factors can help doctors take preventive measures to reduce the likelihood of shoulder dystocia and its complications.
What Causes Shoulder Dystocia?
Shoulder dystocia occurs when there is a mismatch between the baby’s shoulder size and the mother’s pelvic dimensions, making vaginal delivery difficult. Several factors can contribute to this condition:
Fetal Macrosomia (Large Baby Size)
- One of the most common causes of shoulder dystocia is fetal macrosomia, which means the baby weighs more than 8 lbs 13 oz (4,000 grams) at birth.
- Larger babies have broader shoulders, increasing the risk of getting stuck behind the mother’s pelvic bone.
- Gestational diabetes significantly increases the likelihood of macrosomia, as babies born to diabetic mothers tend to be larger.
Maternal Factors (Pelvic Shape & Size)
- Some women have a narrow or small pelvis (cephalopelvic disproportion – CPD), which makes it difficult for the baby’s shoulders to pass through during delivery.
- Obesity and excessive weight gain during pregnancy can also affect the pelvic outlet, increasing the risk of shoulder dystocia.
Prolonged or Difficult Labor
- Dysfunctional labor (slow or stalled labor progression) can increase the risk of the baby getting stuck.
- If labor lasts too long, the baby’s shoulders may become wedged into the birth canal, leading to shoulder dystocia.
Use of Assisted Delivery Tools (Forceps or Vacuum Extractor)
- Doctors sometimes use forceps or vacuum extractors to assist with delivery when labor is prolonged.
- However, if these tools are used incorrectly or with excessive force, they can contribute to the baby’s shoulders becoming trapped behind the pelvic bone.
Post-Term Pregnancy (Overdue Baby)
- Babies born after 40 weeks tend to be larger in size, increasing the risk of shoulder dystocia.
- The placenta may also start to function less effectively, leading to distress and complications during delivery.
Multiple Pregnancies (Twins, Triplets, etc.)
- Carrying twins or triplets increases the chances of abnormal positioning or restricted space in the uterus, which can lead to shoulder dystocia.
Previous Shoulder Dystocia
- Women who experienced shoulder dystocia in a previous pregnancy are at a higher risk of it happening again in subsequent deliveries.
- Doctors should monitor these cases closely and consider early intervention strategies, such as C-section delivery if necessary.
Can Shoulder Dystocia Be Prevented?
While shoulder dystocia is unpredictable, doctors can identify high-risk factors early and take preventive measures to reduce the chances of complications:
Identifying High-Risk Pregnancies
- Doctors should monitor fetal weight, maternal diabetes, and previous obstetric history to determine if a mother is at risk for shoulder dystocia.
Performing an Early C-Section in High-Risk Cases
- If a baby is too large or the mother has had previous shoulder dystocia, an elective C-section may be recommended to prevent complications.
Managing Gestational Diabetes
- Proper blood sugar control during pregnancy can help prevent excessive fetal growth and reduce the risk of macrosomia and shoulder dystocia.
Proper Use of Labor Induction and Delivery Techniques
- Avoiding excessive Pitocin (oxytocin) can help prevent strong, rapid contractions that may increase the likelihood of shoulder dystocia.
- If shoulder dystocia occurs, doctors should use McRoberts maneuver, suprapubic pressure, and other emergency techniques to safely deliver the baby without causing injury.
Medical Negligence and Shoulder Dystocia
In some cases, shoulder dystocia-related injuries occur due to medical negligence, including:
❌ Failure to monitor fetal size and risk factors during pregnancy.
❌ Improper use of forceps or vacuum extractors.
❌ Delayed C-section decision in high-risk cases.
❌ Failure to manage shoulder dystocia properly, leading to birth injuries.
If medical malpractice contributed to a birth injury caused by shoulder dystocia, families may be able to file a legal claim to receive compensation for medical expenses, therapy costs, and long-term care.
How Thomas & Wan LLP Can Help
At Thomas & Wan LLP, we specialize in birth injury cases, including those caused by shoulder dystocia-related medical negligence. Our experienced legal team can help you:
✅ Investigate medical records to determine if malpractice occurred.
✅ Work with medical experts to build a strong case.
✅ Pursue compensation for your child’s medical care, therapy, and long-term needs.
If your baby suffered a birth injury due to improper management of shoulder dystocia, contact Thomas & Wan LLP today for a free consultation.
Shoulder dystocia is a serious childbirth complication that occurs when a baby’s shoulders become trapped behind the mother’s pelvic bone. While some cases are unavoidable, others result from poor medical decisions and negligence.
By identifying risk factors early, managing high-risk pregnancies, and ensuring proper delivery techniques, doctors can reduce the risk of shoulder dystocia and prevent birth injuries.
If you believe medical negligence played a role in your child’s birth injury, reach out to Thomas & Wan LLP for expert legal guidance. We are committed to helping families get the justice and compensation they deserve.
