…demonstrate mixed clinical outcomes following introduction of shoulder dystocia simulation, indicate the need for a reassessment of the recommendations calling for the universal implementation of shoulder dystocia interventional exercises
The uncertainties surrounding the nature of the interventional exercises and the necessary audience, the potential unintended consequences, the questionable improvement in the long-term sequelae of shoulder dystocia along with resource utilization and cost-effectiveness together construct a compelling reason to undertake an adequately powered trial that incorporates long-term follow-ups
Wagner at al. (AJOG, 2021)
Shoulder dystocia is an obstetrical emergency. While there are associated risk factors, they are poor at predicting shoulder dystocia. The majority of cases will occur in women without diabetes whose offspring are within normal weight range. Nor is there any evidence that shoulder dystocia can be prevented. Complications include PPH and brachial plexus injuries. ACOG published guidance in 2017 that has been reaffirmed (2019).
Failure to deliver the fetal shoulder(s) with gentle downward traction on the fetal head, requiring additional obstetric maneuvers to effect delivery
McRoberts maneuver: Best first step (Level B Evidence)
Posterior Shoulder Delivery to reduce shoulder diameter (Level C Evidence)
ACOG Practice Bulletin 178: Shoulder Dystocia
Johns Hopkins Medicine | Gynecology & Obstetrics: Shoulder Dystocia Simulation and Training Videos
The term fetal macrosomia implies growth beyond an absolute birth weight of 4000 grams or 4500 grams, regardless of gestational age. The risk of morbidity for both infants and mothers increases when the birthweight is between 4000 and 4500 grams. Risks for maternal and newborn morbidity rise considerably with birthweights >4500g. A correct diagnosis can only be made after weighing an infant at birth, as ultrasound prediction is not precise.
In the United States, 7.8% of all live-born infants weigh > 4000 grams and 1% weigh > 4500 grams. The most serious complication of fetal macrosomia is shoulder dystocia which complicates 0.2-3.0% of all vaginal deliveries. When the birthweight is > 4500 grams, the shoulder dystocia rate increases to 9-14%. The shoulder dystocia rate increases to 20-50% in the presence of maternal diabetes when the birthweight is > 4500 grams. ‘Large for gestational age (LGA)’ also refers to excessive fetal growth, but rather than absolute weight, LGA is usually defined as ≥90th percentile for a given gestational age.
Note: Upon review of current literature, ACOG states
No single formula based on ultrasound biometry performs significantly better than others for the detection of macrosomia more than 4,500 g
Similar to clinical estimates of fetal weight, ultrasonography can be used most effectively as a tool to rule out macrosomia, which may help avoid maternal and fetal morbidity
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