Shoulder Dystocia During Birth

Shoulder dystocia sounds scary—and it is. This potentially life-threatening complication of vaginal delivery occurs when one of the baby's shoulders (or less frequently both) does not enter the pelvis during the birth as they should, stalling the baby mid-delivery.

Overview

Shoulder dystocia happens in less than 1% of all births but can lead to serious complications for the baby and/or mother. It can also be fatal and is considered a medical emergency when it occurs. This complication is serious because it can delay delivery, trapping the baby. Potential consequences for the baby include:

• Damage to the brachial plexus nerves, which travel from the spinal cord in the neck down the arm. This can cause lasting injury and/or paralysis
• Fractures to the collarbone and arm
• Lack of oxygen (asphyxia). In severe cases, this can cause brain damage or death

The mother can also experience injury during delivery, such as uterine rupture, vaginal damage, hemorrhage, and extensive tearing.

Warning Signs

Because this often unpreventable and unpredictable complication can have such serious consequences, researchers and doctors are interested in finding reliable warning signs for early detection. However, contrary to popular belief, there isn't one exact method to predict when shoulder dystocia will occur.

The factors associated with the highest risk include:

• Fetal macrosomia (babies born over 8 pounds, 13 ounces)
• Mothers who have diabetes and/or are significantly overweight
• Mothers who have had babies with shoulder dystocia before

Other factors that may increase the risk of shoulder dystocia are:

• Advanced gestational age
• High-risk pregnancies, particularly in regards to complications like gestational diabetes
• Induced labor
• Mothers who are petite in size
• Twins or multiple pregnancies

While the above indicators do increase risk, it's not always clear why the complication happens in some pregnancies and not others. However, those with a history of having a delivery with shoulder dystocia have around a 10% to 20% chance of reoccurrence in subsequent births. Particularly troubling is that shoulder dystocia also often happens when no known risk factors are present at all.

Prevention

What do you do if your practitioner feels you're in danger of shoulder dystocia? The answer isn't clear on all counts. We do know that certain positions are more likely to lead to shoulder dystocia, for example, the lithotomy position (lying flat on your back), which can prevent the sacrum from properly moving during birth and therefore narrows the amount of room in your pelvis for the shoulders.

Episiotomy, a surgical cut in the area of skin between the vagina and rectum, is often debated, with one side saying that doing a generous episiotomy allows room for the practitioner to do maneuvers, while the other side argues that the perineum is not what is holding the baby back and should be left intact. Nor is routine cesarean section or induction the answer for all, but sometimes these approaches are used.

Treatment

When shoulder dystocia is diagnosed, your medical team will act quickly to get your baby out. There are several maneuvers that can be done to help solve the problem. Since each birth is different, not every one of these will work every time. Often, multiple maneuvers are tried in very rapid succession to help resolve the situation in a quick, positive manner.

Here are some of the various techniques that are used:

• Gaskin Maneuver: Get the mother into a hands and knees position. This will change the diameters of her pelvis, though this position is not always possible for women using epidural anesthesia.
• McRobert's Maneuver: Flex the mother's legs toward her abdomen and shoulders as she lays on her back, thus expanding the pelvic outlet. One study showed that this alleviated 42% of cases of shoulder dystocia.
• Rubin Maneuver: Two fingers are placed behind the baby's shoulder and push in the direction of the baby's eyes, to line up the shoulders.
• Suprapubic Pressure: Pressure is applied at the pubic bone, not at the top of the uterus. This might allow the shoulder enough room to move under the pubic symphysis.
• Woods Maneuver: This is also known as the corkscrew. Like the Rubin Maneuver, the attendant tries to turn the shoulder of the baby by placing fingers behind the shoulder and pushing in 180 degrees.
• Zavanelli Maneuver: Pushing the baby's head back inside the vagina and doing a cesarean. This is the most frequently asked about method, but also one of the most dangerous.

After the Birth

After a high-risk birth that includes shoulder dystocia, there may be additional things your doctor or midwife will want to watch for in you and your baby, including:

• A baby that is slow to start adjusting to life outside the womb and may require assistance with breathing
• Fetal brachial plexus injury
• Fractures of the baby's collar bone (clavicle) or arm
• Maternal hemorrhage
• Repairs for episiotomy or tearing during the birth
• Uterine rupture