Iatrogenic Shoulder Dystocia?

On my radar this past week was the concept of iatrogenic shoulder dystocia. I had previously read that the single most common risk factor for shoulder dystocia was the use of a vacuum extractor or forceps during delivery. Kathy of Woman to Woman CBE came across a study of more than 12,000 births in two hospitals that showed that the rate of shoulder dystocia (about 1%) remained constant despite differences in the risk factors of parity, birth weight, cesarean delivery, and operative vaginal delivery. The researchers note that this could have implications in defending shoulder dystocia injury cases in which the defense that the doctor should have seen the risks factors and acted on them in advance is used.

Kathy speculated about additional causes of shoulder dystocia:

Maybe it’s time for doctors to start looking at other causes and other forces. Like, iatrogenic shoulder dystocia — shoulders getting caught because the mother is lying on her back, with pressure on her coccyx making it unable to naturally move backwards as the baby moves past it, as well as her not being able to be in a squatting position, which widens the pelvic outlet by a couple of centimeters (without episiotomy). Maybe the baby having to fight against gravity (actually pointing upwards to get past the fixed tailbone) has something to do with it. Maybe the baby not being able to shift and rotate naturally because the mom is not allowed to position herself in such a way as to allow the baby’s shoulders to come free, has something to do with it.

Hypothetically, if shoulder dystocia occurrence were to increase in frequency as a result of the lack of mobility caused by the epidural that is (usually) necessitated by the induction of labor which was scheduled to prevent the baby from getting too big and experiencing shoulder dystocia… it would be like a dog chasing its tail if the very tactic attempted to get a suspected big baby out safely was actually mechanically impairing the normal process of childbirth. Naturally, a midwife or doctor can still perform disimpaction maneuvers on a woman using epidural anesthesia by lifting and moving her into various positions, but it’s still an interesting conjecture.


Back at Mom’s Tinfoil Hat, Hilary found a study showing that iatrogenic shoulder dystocia is a possibility under certain conditions:

“The triad of labor induction, oxytocin use, and birth weight greater than 4500 g yielded a cumulative odds ratio of 23.2 (95% CI 17.3-31.0) for shoulder dystocia.”

For those who don’t understand odds ratios, it says that with that triad (large baby, induction and pitocin), there will be a shoulder dystocia also occurring 23 times more likely than if this triad did not exist. It seems to me that labor induction and use of pitocin actually increases the risk of a dystocia, instead of decreasing it, especially if it is likely that the baby is large.

Studies have consistently shown that inducing labor for suspected macrosomic baby does not prevent c-sections, shoulder dystocia or birth injuries. The idea that induction actually might CAUSE the emergent situation that it seeks to prevent is worthy of further exploration.


Software called the CALM Shoulder Screen was developed by LMS Medical which claims to be able to predict not shoulder dystocia, but specifically shoulder dystocia with brachial plexus injury. The goal is to prevent medico-legal and financial issues associated with brachial plexus injury. In fact, “its detection rates between 30% and 61% could translate to multi-million dollar savings for large hospital systems or insurers.” Using an algorithm based on anthropometric maternal and fetal characteristics, the CALM software claims to assess the risk of shoulder dystocia with injury at or before the onset of labor, greatly improves detection rate with a relatively small increase in the rate of cesarean, and enables clinical teams to communicate risk effectively to patients when recommending a course of action.




However, shoulder dystocia with brachial plexus injury can also result from care provider management, either in applying excessive traction to the infant’s head while its shoulder was stuck or in inducing labor to try to prevent the very problem that it might be creating. In that case, the software must be missing an important variable since the program’s goal is to provide information with which to determine the safest and least expensive course of action. But what if the management causes the injury? The dog chases its tail again.

Contrary to popular belief, cesareans do not render a baby immune from permanent brachial plexus injuries. One can only hope that shoulder dystocia will be handled as well as this.


Picture links to YouTubeWith the knowledge that I have, I don’t think I can imagine suing a care provider for a shoulder dystocia related injury. When selecting a care provider and certainly prior to labor, I would ask about the institution’s protocol for shoulder dystocia and other emergencies along with their personal experience. If they follow the protocol step-by-step without frantically applying traction and injury ensues, why would I sue? They would have done everything they could do. Shoulder dystocia is extremely rare and shoulder dystocia with permanent injury is not typical. The alternative to sitting down with each patient and educating them on exactly what they can expect in the event of an emergency seems to be prophylactic c-sections for everyone “measuring large” and aggressive management of labor.

Prompt handling of emergencies by a board-certified obstetrician and access to technology are the most commonly provided justifications for why women should give birth in a hospital. Consumers should at a minimum be given a checklist of exactly how each emergency will be handled. More importantly, there should be ample time and opportunity to discuss how emergencies are handled during a prenatal appointment.  The question is whether or not hospitals will inform the consumer that a percentage of hospital emergencies could be of iatrogenic origin and let them know whether they are truly adequately staffed to resolve every emergency at the drop of a hat.


Our Bodies, Our Blog recently cited an article that appeared in the December issue of the journal Obstetrics and Gynecology entitled, “Reducing Obstetric Litigation Through Alterations in Practice Patterns,” which looked at 189 closed obstetric liability claims between 2000-2005 to classify whether the incidents could be attributed to what they consider substandard care. OBOB wrote:

Among their conclusions, the authors state, “First, even when judged by treating providers or defense consultants, most money currently paid in conjunction with obstetric malpractice cases is a result of actual substandard care resulting in preventable injury.”

If I read these findings correctly, it shows that the highest payouts are being awarded to women who were actually victims of malpractice and not to what some refer to as greedy people looking to exploit the system to profit from a tragedy. That would mean that the legal system is working effectively and benefiting the proper parties. So if doctors are not indeed being sued for birth injuries that are beyond their control, as the typical argument for the rising c-section rate goes, then of what are they actually afraid?


There seems to be a great aversion to vaginal birth taking its course.