Risk Factors for Expectant Parents

In pregnancy books, the birth canal is shown as very straight forward. During the birth, the baby comes down and out and that's the end of it. But sometimes the baby's shoulder can get stuck on the mother's pelvic bone. It is possible for the tender nerves in the baby’s neck to be injured during birth when this birthing emergency, called shoulder dystocia, occurs. This type of injury, called a brachial plexus injury, can cause one or both arms to be paralyzed. Children with permanent and severe brachial plexus injuries suffer a lifetime of pain, therapy, invasive tests, possible surgeries with long recovery times and emotional distress. Unfortunately, birthing practitioners and pregnancy books rarely discuss the possibility of this birthing emergency with expectant mothers.

There are warning signs that may be linked to an increased risk for this birthing emergency. More importantly, there are steps an expectant mother and a high-risk practitioner can take to possibly reduce the risk of injury.

Risk Factors for Shoulder Dystocia:

  • Suspected large baby - over 8 lbs. 14 oz.
  • Maternal diabetes / gestational diabetes (fetal macrosomia & assymetry)
  • Maternal obesity
  • An overdue baby - over 40 weeks
  • Short maternal stature
  • Contracted or flat (platypelloid) pelvis
  • Maternal weight gain -more than 35 lbs.
  • Protracted first stage of labor
  • Prolonged second stage of labor

Risk Factors for Shoulder Dystocia That May Be Associated with Prior Pregnancies:

  • A history of shoulder dystocia during a previous delivery
  • A history of giving birth to large babies
  • Eight years or more since your last birth

Other Factors That May Be Associated with an Increased Risk for Shoulder Dystocia:

Epidural: Because of loss of sensation from an epidural, the mother may not be able to feel the 'pushing' sensation and the baby might descend in a slightly awkward position.

Tools: The use of tools (for example, forceps or vacuum) to help the baby descend may possibly increase the risk of shoulder dystocia as well.

Labor Induction: There appears to be a possible association between an increased risk for shoulder dystocia and the use of labor-inducing drugs.

Please Note: Even with these risk factors, more women have uneventful birthing experiences than those whose labors are complicated by shoulder dystocia. Moreover, shoulder dystocia can occur in the absence of these factors.

Risk Factors For Brachial Plexus Injury (without the occurrence of shoulder dystocia):

  • Uterine tumors
  • Tumors in the neck of the baby
  • Viral disease
  • Other abnormalities
  • Breech fetal position at time of birth


What Can You Do To Try and Lessen Your Risk of Encountering Shoulder Dystocia?

  • Discuss with your practitioner your concerns about shoulder dystocia risks, and ask what steps you can take now to try and reduce those risks. For example, he/she may suggest that you follow a gestational diabetes diet throughout your pregnancy. See the list of questions below that you may want to use as a guideline to “Opening up the Conversation” with your practitioner.
  • Discuss with your practitioner the appropriateness of the environment in which you plan to give birth. For example, if you do have some of the risk factors for shoulder dystocia or if you have a history of difficult births, you may want to consider a hospital birth instead of a home birth so that you can have better access to emergency facilities, equipment and personnel if needed.
  • Ask if he/she thinks that consulting with a specialized high-risk practitioner would be more appropriate for your pregnancy and delivery.
  • Ask about his/her shoulder dystocia / brachial plexus injury experience.
  • Use the Internet as a research tool, and educate yourself as much as possible.



“Opening Up The Conversation”

  1. I am concerned about my risk(s) for encountering shoulder dystocia. What can you tell me to alleviate my concerns ?

  2. After evaluating my past and current medical and childbearing history, do you think I am a candidate for having a large baby?

  3. If it was determined or suspected that I am carrying a large baby, would you recommend a C-section? Under what other circumstances would you recommend a C-section?

  4. Have you determined if my pelvic outlet can accommodate the safe passage of a baby? Do I have a flat (platypelloid) or small pelvis?

  5. How many times have you encountered shoulder dystocia during the delivery process, and do you feel confident about delivering a baby with an occurrence of shoulder dystocia? What are some of the maneuvers you will use if shoulder dystocia becomes an issue during my birth?

  6. Does the hospital I will be delivering at have a specific protocol for handling shoulder

  7. What is your opinion of the reliability of using ultrasound to determine fetal weight, and will I be given this test one or more times to estimate fetal weight?

  8. If you are unable to attend the delivery of my baby, who will? And are they knowledgeable about shoulder dystocia births? (Be sure to meet with and question all the doctors/midwives in the practice.)

  9. Have you ever injured a child during the birth process?



Information sources used in the preparation of this material: Shoulder Dystocia and Birth Injury: Prevention and Treatment by James. A. O’Leary, MD (McGraw-Hill, 1992); the informational website of Dr. O’Leary: www.shoulderdystocia.com; informational materials published by the Brachial Plexus Program at Texas Children’s Hospital, Houston, TX; and the informational website of the Brachial Plexus Program at Texas Children’s Hospital which can be accessed through the main Texas Children’s Hospital website: www.texaschildrenshospital.org.


The intention of this information sheet is to educate expectant parents about one specific birthing emergency. The information contained herein is meant to be informative and does not represent medical advice or recommendations.