Sonographic Examination of The Fetus Vis-à-Vis Shoulder Dystocia: A Vexing Promise

Shoulder Dystocia: Challenging Basic Assumptions

Most of our knowledge pertaining to this obstetric emergency has emanated from case reports and retrospective studies that have subsequently resulted in empirical management protocols. This article has identified the existence of large gaps in our clinical knowledge base regarding the prevention and resolution of shoulder dystocia, as well as its long-term sequelae. We have attempted to challenge current recommendations regarding whether prophylactic cesarean delivery should be performed based on estimated fetal weight alone or a prior history of shoulder dystocia, shoulder dystocia management techniques, what defines "excessive" traction, and the role of simulation training for all clinicians.

Antenatal risk prediction of shoulder dystocia: influence of diabetes and obesity: a multicenter study

PURPOSE

To estimate the risk of shoulder dystocia (SD) in pregnancies with/without maternal diabetes or obesity; to identify antenatal maternal and fetal ultrasound-derived risk factors and calculate their contributions.

METHODS

A multicenter retrospective analysis of 13,428 deliveries in three tertiary hospitals (2014-2017) with fetal ultrasound data ≤ 14 days prior to delivery (n = 7396).

INCLUSION CRITERIA

singleton pregnancies in women ≥ 18 years old; vertex presentation; vaginal delivery at ≥ 37 weeks of gestation. Estimated fetal weight (EFW) and birth weight (BW) were categorized by steps of 250 g. To evaluate risk factors, a model was performed using ultrasound data with SD as the dependent variable.

RESULTS

Diabetes was present in 9.3%; BMI ≥ 30 kg/m² in 10.4% and excessive weight gain in 39.8%. The total SD rate was 0.9%, with diabetes 2.0% and with obesity 1.9%. These increased with BW 4250-4499 g compared to 4000-4249 g in women with diabetes (12.1% vs 1.9%, P = 0.010) and without (6.1% vs 1.6%, P < 0.001) and at the same BW threshold for women with obesity (9.6% vs 0.6%, P = 0.002) or without (6.4% vs 1.8%, P < 0.001). Rates increased similarly for EFW at 4250 g and for AC-HC at 2.5 cm. Independent risk factors for SD were EFW ≥ 4250 g (OR 3.8, 95% CI 1.5-9.4), AC-HC ≥ 2.5 cm (OR 3.1, 95% CI 1.3-7.5) and diabetes (OR 2.2, 95% CI 1.2-4.0). HC/AC ratio, obesity, excessive weight gain and labor induction were not significant.

CONCLUSION

Independent of diabetes, which remains a risk factor for SD, a significant increase may be expected if the EFW is ≥ 4250 g and AC-HC is ≥ 2.5 cm.

Ultrasound for the Pregnant Person With Diabesity

Diabetes and obesity increase the risk of congenital anomalies, but the putative mechanisms of this increased risk are not fully elucidated. In this chapter, we delve into sonographic characteristics associated with diabetes and obesity, including fetal structural anomalies, functional cardiac alterations, and growth abnormalities. We will also discuss the technical challenges of imaging in the patient with diabesity and propose methodologies for optimizing imaging. Lastly, we will address the prevention of workplace-associated musculoskeletal disorders injury for sonographers.

Sonographic Estimated Fetal Weight among Diabetics at ≥ 34 Weeks and Composite Neonatal Morbidity

Objectives  The objective was to assess the composite neonatal morbidity (CNM) among diabetic women with sonographic estimated fetal weight (SEFW) at 10 to 90th versus >90th percentile for gestational age (GA). Study Design  The inclusion criteria for this retrospective study were singleton pregnancies at 34 to 41 weeks, complicated by diabetes, and that had SEFW within 4 weeks of delivery. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated. Results  Among the 140 cohorts that met the inclusion criteria, 72% had SEFW at 10th to 90th percentile for GA, and 28% at >90th percentile. Compared with women with diabetes with last SEFW at 10th to 90th percentile, those with estimate > 90th percentile for GA had a significantly higher rate of CNM (13 vs. 28%; OR, 2.65; 95% CI, 1.07-6.59). Among 109 diabetic women who labored, the rate of shoulder dystocia was significantly higher with SEFW at >90th percentile for GA than those at 10th to 90th percentile (25 vs. 2%; p  = 0.002); the corresponding rate of CNM was 29 versus 10% ( p  = 0.02). Conclusion  Among diabetic women with SEFW > 90th percentile for GA, CNM was significantly higher than in women with estimate at 10 to 90th percentile. Despite the increased risk of CNM, these newborns did not have long-term morbid sequela.