Is fetal manipulation during shoulder dystocia management associated with severe maternal and neonatal morbidities?

Predictors of maternal and neonatal outcomes in labors complicated by shoulder dystocia: a comparative analysis

INTRODUCTION

Studies investigating the risk factors associated with unfavorable maternal/neonatal outcomes in cases of shoulder dystocia are scarce. This study aims to uncover the predictive factors that give rise to unfavorable outcomes within the context of shoulder dystocia.

MATERIALS AND METHODS

Medical records of pregnancies complicated by shoulder dystocia was obtained between 2008-2022 from a single tertiary center. This study involved the comparison of sociodemographic, sonographic, and delivery characteristics among pregnancies complicated by shoulder dystocia resulting in favorable vs. unfavorable maternal/neonatal outcomes.

RESULTS

A total of 275 pregnancies were analyzed, with 111 (40.3%) classified as unfavorable outcomes and 164 (59.7%) as favorable outcomes. Employing a multivariable regression analysis, several independent associations were identified with unfavorable maternal/neonatal outcomes. Specifically, short maternal stature, pre-gestational diabetes, vacuum extraction, Wood's screw maneuver, and macrosomia merged as significant predictors of unfavorable maternal/neonatal outcomes.

CONCLUSION

Short maternal stature, pre-gestational diabetes, vacuum extraction, Wood's screw maneuver, and macrosomia may all contribute to poor maternal/neonatal outcomes in shoulder dystocia cases. This knowledge allows clinicians to improve their decision-making, patient care, and counseling.

A critical evaluation of the external and internal maneuvers for resolution of shoulder dystocia

In the management of shoulder dystocia, it is often recommended to start with external maneuvers, such as the McRoberts maneuver and suprapubic pressure, followed by internal maneuvers including rotation and posterior arm delivery. However, this sequence is not based on scientific evidence of its success rates, the technical simplicity, or the related complication rates. Hence, this review critically evaluates the success rate, technique, and safety of different maneuvers. Retrospective reviews showed that posterior arm delivery has consistently higher success rates (86.1%) than rotational methods (62.4%) and external maneuvers (56.0%). McRoberts maneuver was thought to be a simple method, however, its mechanism is not clear. Furthermore, McRoberts position still requires subsequent traction on the fetal neck, which presents a risk for brachial plexus injury. The 2 internal maneuvers have anatomic rationales with the aim of rotating the shoulders to the wider oblique pelvic dimension or reducing the shoulder width. The techniques are not more sophisticated and requires the accoucher to insert the correct hand (according to fetal face direction) through the more spacious sacro-posterior region and deep enough to reach the fetal chest or posterior forearm. The performance of rotation and posterior arm delivery can also be integrated and performed using the same hand. Retrospective studies may give a biased view that the internal maneuvers are riskier. First, a less severely impacted shoulder dystocia is more likely to have been managed by external maneuvers, subjecting more difficult cases to internal maneuvers. Second, neonatal injuries were not necessarily caused by the internal maneuvers that led to delivery but could have been caused by the preceding unsuccessful external maneuvers. The procedural safety is not primarily related to the nature of the maneuvers, but to how properly these maneuvers are performed. When all these maneuvers have failed, it is important to consider the reasons for failure otherwise repetition of the maneuver cycle is just a random trial and error. If the posterior axilla is just above the pelvic outlet and reachable, posterior axilla traction using either the accoucher fingers or a sling is a feasible alternative. Its mechanism is not just outward traction but also rotation of the shoulders to the wider oblique pelvic dimension. If the posterior axilla is at a higher sacral level, a sling may be formed with the assistance of a long right-angle forceps, otherwise, more invasive methods such as Zavanelli maneuver, abdominal rescue, or symphysiotomy are the last resorts.

Impact of fetal manipulation on maternal and neonatal severe morbidity during shoulder dystocia management

PURPOSE

There are few data on maternal and neonatal morbidities associated with shoulder dystocia (SD), depending on the use of fetal manipulation (FM). A prior 5-year study was conducted in our center in 2012 for this purpose. Our objective was to compare severe maternal and neonatal morbidities according to FM execution in a larger cohort.

METHODS

We conducted a retrospective study between 2007 and 2020. SD was considered when additional maneuvers were required to complete a delivery. Severe maternal morbidity was defined as the occurrence of obstetric anal sphincter injury (OASI). Severe neonatal morbidity was defined as Apgar < 7 at 5 min and/or cord arterial pH < 7.1 and/or or a permanent brachial plexus palsy. We studied these data in the FM group compared to the non- FM group.

RESULTS

FM was associated with increased OASI rates (21.1% vs. 3.8%, OR = 6.72 [2.7-15.8]). We found no significant difference in severe neonatal morbidity. Maternal age > 35 and FM appear to be associated with the occurrence of OASI, with ORa = 13.3 [1.5-121.8] and ORa = 5.3 [2.2-12.8], respectively. FM was the only factor associated with the occurrence of severe neonatal morbidity (ORa = 2.3 [1.1-4.8]. The rate of episiotomy was significantly decreased (20% versus 5% p < 0.05) and there was an increase in the rate of SD managed with FM in our center.

CONCLUSION

FM is the only factor associated with an increased risk of OASI. In case of failure of non-FM maneuvers, the rapid implementation of FM maneuvers resulted in no difference regarding severe neonatal morbidity.

Fetal growth velocity in diabetics and the risk for shoulder dystocia: a case-control study

INTRODUCTION

Shoulder dystocia complicates up to 3% of vaginal births. The clinical ability to predict shoulder dystocia is limited, especially among diabetic women. We sought to evaluate if fetal growth trajectory measured from ultrasonographic (US) estimated fetal weight (EFW) percentiles was associated with increased risk for shoulder dystocia.

METHODS

We performed a case-control study among women diagnosed with diabetes at a single institution between 2005 and 2015. Two diabetic controls without shoulder dystocia based on the year of delivery were included for each woman with a shoulder dystocia. Women with a single EFW measurement, delivery by cesarean, or multiple gestation were excluded. Demographic and US data were collected. Fetal growth trajectory was calculated from EFW measurements in the last two growth ultrasound scans performed closest to delivery. We compared the odds of EFW percentile change per week above specific thresholds for shoulder dystocia cases versus controls. The following cutoffs were generated: a mean percentile per week increase of > 0%, ≥ 0.5%, ≥ 1%, and ≥ 2%. Among those with EFW percentile changes that decreased (<0%), we evaluated whether odds of an abdominal circumference (AC) > 75th percentile or an EFW > 75th percentile was higher for women with shoulder dystocia. The primary exposure was increased growth trajectory. Secondary outcomes included analysis of the following adverse neonatal outcomes: (i) low 5 minutes Apgar score, (ii) rates of NICU admission, and (iii) neonatal demise.

RESULTS

Of 3954 diabetics, we identified 68 cases with shoulder dystocia and 136 controls who did not have shoulder dystocia. Women who experienced a shoulder dystocia were more likely to be of advanced maternal age as compared to those without a shoulder dystocia (41.9% versus 23.5, p = .01); all other demographic characteristics were similar between groups. At growth trajectory cutoffs of > 0%, ≥ 0.5%, ≥ 1%, and ≥ 2% per week, odds ratios were increased among shoulder dystocia cases versus controls (OR = 1.8, 95% confidence interval (CI) = 0.9-3.3; OR = 1.6, 95% CI = 0.8-3.2; OR = 1.7, 95% CI = 0.7-3.9; and OR = 1.8, 95% CI = 0.6-5.3; respectively); however, this was not statistically significant. For women with fetal growth trajectories that decreased (< 0%), shoulder dystocia was associated with increased odds of fetal AC > 75th percentile and overall growth > 75th percentile (OR = 3.3, 95% CI = 1.5-7.1, OR = 4.8, 95% CI = 1.3-17.4, respectively). There was no difference in neonatal outcomes between shoulder dystocia cases and controls.

CONCLUSION

Future research is required to determine if fetal growth velocity proves to be a useful tool in identifying women at increased risk for shoulder dystocia. Larger studies are required for precise estimates of risk, and associated neonatal outcomes.