Shoulder Dystocia is a type of complication that may occur during delivery. Sometimes during the course of a normal vaginal delivery, the head of the baby is delivered but the shoulders get stuck behind the mother's pubic bone and the baby cannot be delivered promptly. This condition is termed as a shoulder dystocia. This article talks about the various ways in which a shoulder dystocia can be managed during birth.
Ways To Resolve Shoulder Dystocia
There are many different maneuvers that can be tried to resolve a shoulder dystocia. However, before getting into any of these maneuvers, it is important to perform the following tasks:
· Summon another obstetrician to stand by and also make sure additional nurses and medical personnel are present for assistance.
· Make sure someone is keeping a note of how much time has passed since the delivery of the baby's head.
· Have neonatal and pediatric experts on stand by in case there is any fetal injury during birth or if the baby needs to be resuscitated after birth.
· Have an anesthetic on-the-ready in case surgery needs to be performed.
Once the above tasks are taken care of, the following procedures may be used to resolve the shoulder dystocia.
1. The McRoberts Maneuver:
This is usually the first maneuver that is used when a shoulder dystocia occurs. This maneuver requires flexing the mother's legs sharply onto her abdomen. What this essentially means is that the obstetrician maneuvers the maternal legs so that the knees are as close to the chest as possible. Once this is done, the maternal pelvis gets enlarged as the sacrum gets flattened. This extra space created in the pelvic outlet is usually enough to free the stuck shoulder so that the baby is delivered easily. The McRoberts Maneuver is also known as the Legs Maneuver.
2. Suprapubic Pressure:
A shoulder dystocia occurs because the anterior shoulder of the baby is stuck behind the mother's pelvic bone. To free the shoulder, the obstetrician may use manual pressure. This type of pressure is called the suprapubic pressure. Here's how it is typically applied:
The obstetrician places his fist on the mother's abdomen slightly above the pubic bone.
The stuck fetal shoulder is then pushed in either direction so that it assumes an oblique orientation position instead of the anterior-posterior position that is usually responsible for the shoulder dystocia in the first place. As the entrapped shoulder is now aligned obliquely to the pelvic bone, it can then be delivered easily.
When using this maneuver, it is imperative that the pressure applied is suprapubically so that the impacted shoulder can be freed from beneath the maternal pelvic bone. If fundal pressure is applied, the shoulder will only get stuck further under the pelvic bone and the shoulder dystocia will not be resolved properly.
In as many as 55% to 60% of all shoulder dystocia cases, simply using the McRoberts Maneuver in combination with applying Suprapubic Pressure is all that is required by the obstetrician to free the impacted shoulder and resolve shoulder dystocia during birth.
Using the McRoberts maneuver along with applying suprapubic pressure does not involve any kind of direct fetal manipulation. Therefore, both these procedures are considered to be extremely safe for the baby. However, if the maternal legs and thighs are flexed too forcefully, there is a danger of some degree of injury to the mother.
3. Woods Screw Maneuver:
While the first two maneuvers mentioned above simply require repositioning the mother and applying external pressure, the Woods Screw maneuver requires internal manipulation. In this procedure, the obstetrician reaches into the birth canal with their hands and tries to rotate the posterior shoulder of the baby much like rotating a corkscrew. The front surface of the posterior shoulder is where the pressure is applied, which helps to release the stuck anterior shoulder and the baby can then be delivered.
4. Rubin's Maneuver:
This maneuver can be called a variation of the Woods Screw maneuver. In this procedure, pressure is applied on the posterior surface of the baby's posterior shoulder as opposed to the anterior surface. This pressure, when applied while rotating the baby's shoulders, helps to orient the baby in the oblique position thereby reducing the distance between both the shoulders, which in turn helps to deliver the stuck baby.
5. Posterior Arm Sweep Maneuver:
In this maneuver, the posterior arm and shoulder of the baby are delivered manually. The obstetrician reaches into the birth canal and locates the posterior arm of the fetus. The arm is then swept across the chest of the fetus and is pulled out of the birth canal. This is known as delivering the posterior fetal arm. Once this maneuver is carried out, the stuck anterior shoulder can be rotated and freed easily, thereby delivering the baby in due course.
While the posterior arm sweep maneuver is quite effective, a significant risk during the maneuver is that of causing a humeral fracture, which is a fracture to the upper bone of the baby's arm. However, a humeral fracture is not as bad as it sounds and in almost all cases heals up completely. Thus, if other maneuvers fail to resolve the shoulder dystocia during birth, then the posterior arm sweep maneuver should be used in spite of the added risk of a humeral fracture.
NOTE: A procedure known as an Episiotomy (surgical incision) may have to be carried out for successful resolution of shoulder dystocia. If internal manipulation and rotation maneuvers such as Woods screw, Rubin's etc have to be performed to release the dystocia, there may not always be enough room for the obstetrician to put his hands inside the birth canal. Thus, to make some space to allow the hands to enter the vaginal canal, an episiotomy may be performed. Do note that an episiotomy on its own cannot resolve shoulder dystocia, but merely aids the other maneuvers.
Most shoulder dystocia cases can be managed by using any of the above 5 maneuvers. Do make sure that more than 30 seconds have not passed on any one maneuver. If a particular maneuver does not work within 30 seconds, it is advisable to move on to the next. However, even after trying all these maneuvers if the shoulder dystocia still persists, it may be time to perform the following rescue maneuvers.
6. Zavanelli Maneuver:
This maneuver should only be used when all others fail and for a severe shoulder dystocia. In the Zavanelli maneuver, the obstetrician aims to push the delivered head of the baby back through the birthing canal into the maternal pelvis. As soon as the head is successfully pushed back into the pelvis, an emergency cesarean section is carried out and the baby is delivered surgically.
Although the Zavanelli maneuver has been reported to be very successful in releasing extreme cases of shoulder dystocia, it should only be used in an absolute worst case scenario as it is known to cause both maternal and fetal injury.
7. Symphysiotomy:
A symphysiotomy refers to a surgical procedure wherein the maternal symphysis (the pubic bone and ligaments) is cut by the obstetrician. This helps to cut out a space that is about 2 cm to 3 cm wide. The pelvis is thus widened and the baby can be delivered.
After a symphysiotomy the mother's bladder continues to drain for five days. She has to lie on her side for at least 3 days of the five, and the mother's knees may even be tied together to ensure that the position is maintained. The urinary tract can also get damaged after this procedure. Thus, as is evident, a symphysiotomy is very tough on the mother and is thus hardly ever performed in the US.
8. Fetal Clavicle Fracture:
Another procedure that is sometimes used to resolve a shoulder dystocia is the intentional fracturing of the fetal clavicle bone. Direct upward pressure is applied to the clavicle bone of the fetus in order to fracture it so that the distance between the two fetal shoulders is reduced, thereby freeing the impacted shoulder and enabling delivery of the baby.
However, it is not easy to fracture the clavicle because it is a very strong bone. Most documented cases of resolving shoulder dystocia in this manner involve fetuses that have already died but have to be removed from the maternal pelvis for the safety of the mother.
A shoulder dystocia can thus be managed and resolved during birth by using any of the professional medical maneuvers detailed herein.
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