Dealing with Shoulder Dystocia

There are several obstetric emergencies, but the mother of them all is shoulder dystocia. We hear the term shoulder dystocia, but what does the term really mean? When confronted with shoulder dystocia during a delivery, the delivering doctor must know not only what to do, but also must do it well. There are two components which make shoulder dystocia the mother of all obstetrics emergencies. The first one is the timing; two minutes is about all you have. And the second component is that because of the two-minute timeline, whatever you’re doing must work. Treatment needs to be fast and effective.

The emergency is created by the possibility that the baby’s umbilical cord will be compressed by the baby’s shoulder being caught on the mother’s pubic bone. If this happens, your doctor has about two minutes to solve the problem or risk the possibility of delivering a baby with permanent cognitive impairment. I recommend you ask your doctor how he or she manages shoulder dystocia before you deliver your baby.

Although we try to anticipate shoulder dystocia by identifying moms and babies we think might be high-risk, the likelihood is that shoulder dystocia is most often unpredictable. In my experience, there are two groups that have difficulty with shoulder dystocia. Diabetic mothers are likely to have bigger babies, babies that are large for gestational age. These babies often have big shoulders and big chests. Another group of women who have big babies have them simply because the fathers are big.

Cleveland Clinic has a good online article covering shoulder dystocia. The article does offer as one suggestion to have a large episiotomy. I don’t find this suggestion helpful. The problem of managing shoulder dystocia is not the soft tissue of the vulva or perineum, the tissue between the vagina and the rectum where episiotomies are done. The problem is getting the front shoulder stuck on the pubic bone before the baby’s head descends into the vagina.

How do you diagnose shoulder dystocia? Usually it is associated with a prolonged second stage of labor. In other words, there is a lot of pushing. The baby will almost crown, but not completely crown. There is a temptation to use forceps or suction, but pulling on the head and neck of the baby will not bring about birth. The problem is the blockage of the shoulders by the pubic bone. With shoulder dystocia, the front shoulder of the baby is wedged against the mother’s pubic bone, which will not expand to create enough room for the baby to pass through to the birth canal.

Excessive traction or pulling on the baby’s head and neck with forceps or suction can dislocate the neck and cause long-term or permanent paralysis. In medicine, as in many other areas, we consider benefit vs risk. With shoulder dystocia, traction on the head creates much risk with no benefit. So, slow progress in the pushing stage is probably your first and best warning of the danger to come.

I have found that there are really two maneuvers which are absolutely essential with shoulder dystocia.  In my experience, I would first try the McRoberts maneuver. I was using the McRoberts maneuver before I knew McRoberts had named it. In my residency, the nurses in labor and delivery were skilled in the McRoberts maneuver and I learned it from them.

With the McRoberts maneuver, the pregnant woman’s knees must be raised up against her chest. The point of the knees being moved to the chest is to lift the woman’s hips off the delivery surface. The pubic bone cannot expand, but raising the woman’s hips off the bed makes room in the tailbone area for the tailbone to expand, allowing more room for the baby’s shoulders to pass into the birth canal.

Sometimes the McRoberts maneuver does not make enough room for the baby to pass into the birth canal. If the McRoberts maneuver fails, the doctor can deliver the baby’s arm positioned near the mother’s back. Some authors indicate that either the front or the back arm can be delivered. In my experience, delivering the back (posterior arm) works much better because that is where the room is that you need to bend the baby’s elbow and extend the baby’s shoulder in order to deliver the baby’s hand and then the arm.

I did my residency in St. Paul, MN, which at that time had a large Hmong population. Hmong women are small, and I had a Hmong mother 4 feet 9 inches tall in labor and the baby weighed 10 pounds. The McRoberts maneuver didn’t free up enough space to deliver the baby. I delivered the posterior arm, but still couldn’t deliver the baby. I then rotated the baby 180 degrees so the arm that had been in the front was now in the back and I delivered the second arm from this posterior position. Once both arms were delivered, the baby followed easily. The baby’s Apgars were nine and ten. Mother and baby did well.

The Cleveland Clinic article also mentions what is called the Zavanelli maneuver, but it involves rotating the baby’s head. With this maneuver, the fetal head is rotated to make the back of the baby’s head turn toward the front of the mother by flexing the baby’s neck and pushing the baby’s head back up into the uterus, effectively reversing the important movements of labor. Although this relieves the compression on the baby’s umbilical cord, the baby’s head is then held in place with a doctor’s or nurse’s hand until an emergency C-section can be performed. In other words, the baby’s head is pushed back up into the uterus to relieve cord compression and then the baby is delivered by C-section.

A word of caution about rotating a baby’s head. You cannot turn the head 360 degrees. The delivering doctor must know the location of the front of the baby and the back of the baby and which direction to turn the baby’s head and not exceed 90 degrees of rotation.

Again, I would not recommend the Zavanelli maneuver because getting the mother prepared for a C-section takes a lot of time, time you don’t really have. Furthermore, doing a C-section with the baby that far down in the pelvis would be very difficult, requiring a large uterine incision.

In summary, shoulder dystocia is the emergency of obstetric emergencies. Providers are wise to be aware of this possible emergency and be prepared to act quickly and effectively to deliver the baby. Traction or pulling on the baby’s head is not an option. In my experience, the McRoberts maneuver and delivery of the posterior arm are the best choices giving the best results.