Contemporary OB/GYN on Suspected Macrosomia and Taking Responsibility

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Reader Lori found a copy of Contemporary OB/GYN at her 29 week appointment and read the article ”How should we respond to the trend of increasing cesarean delivery?” On behalf of all of the women who sat through appointments listening to over-the-top tales of how giving birth would result in shoulder dystocia and endured descriptions during labor of fetal death in an attempt to encourage them that giving birth vaginally was too dangerous for them without any solid evidence for such a recommendation, I applaud Marci G Adams, MPH, Emmet Hirsch, MD, Scott N MacGregor, DO, Carolyn V Kirschner, MD, and Richard K Silver, MD, for their work on this commentary.


Here are a few excerpts that caught my eye: 

CD for suspected macrosomia

 Although avoiding shoulder dystocia and permanent brachial plexus injury are appropriate goals, performing CD for suspected macrosomia is limited by the inaccuracy of ultrasound estimations of fetal weight. The ability to predict shoulder dystocia is poor, and the likelihood of permanent brachial plexus injury associated with shoulder dystocia is low.37 The reported incidence of shoulder dystocia ranges from 0.6% to 1.4%. Frequency of brachial plexus injury after shoulder dystocia ranges from 9% to 26%, and most cases resolve without permanent disability.38,39 For example, in the experience at a tertiary center during a 23-year period that included almost 90,000 deliveries, brachial plexus injury occurred in 1 in 1,000 births with vaginal delivery, and permanent injury occurred in 12% of those cases.38 In other words, permanent brachial plexus injury occurred once in every 10,000 deliveries.

Among infants weighing more than 4,000 g, and even more than 4,500 g, the frequency of brachial plexus injury is low, even in diabetic pregnancies.40,41 Estimates suggest that more than 1,000 prophylactic CDs would be required to avoid a single permanent brachial plexus injury in both diabetic and nondiabetic populations, making the objectives of prediction and prevention untenable.37,39 An alternative strategy of team training in shoulder dystocia management is gaining popularity.42 Skills, drills, and simulation programs appear effective and probably should be propagated into all obstetric facilities. An alternative strategy to be tested prospectively would be to establish more stringent labor-management criteria for suspected cases of macrosomia, predicated on progress in both descent and dilation during the first and second stages. Using separate guidelines for such patients could reduce the CD rate in these women, especially when ultrasound fetal weight estimates exceed the actual fetal weight. A randomized study evaluating this strategy would only need to demonstrate that laboring these women with revised guidelines results in a modest reduction of abdominal delivery without increasing the frequency of shoulder dystocia.


From the conclusion:

Obstetric providers must take our share of responsibility for the tremendous increase in the CD rate and the associated life-threatening maternal complications that result from multiple procedures. We must not continue to consider obstetric interventions in a laboring patient in the context of the index pregnancy alone. Rather, the maternal risk of the initial and each subsequent abdominal delivery must be integrated into management decisions. This framework resembles an internist’s approach to hypertension, in which the decision to institute therapy is less predicated on its short-term effect than on the subsequent years of improved health and greater survivability associated with reduced blood pressure.


Nothing short of a public health campaign orchestrated by our specialty, with significant investment of resources, will turn this tide.


What do you think of the article?