[Epidemiology of shoulder dystocia]

Predictors of shoulder dystocia at the time of operative vaginal delivery: a prospective cohort study

Our aim was to identify factors associated with shoulder dystocia following an attempted operative vaginal delivery (aOVD) in a prospective cohort study and to evaluate whether these factors can be used to accurately predict shoulder dystocia by building a score of shoulder dystocia risk. This was a planned secondary analysis of a prospective cohort study of deliveries with aOVD at term from 2008-2013. Cases were defined as women with shoulder dystocia following an aOVD defined as a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on the fetal head to effect delivery of the shoulders. Multivariate logistic regression analyses were performed to determine risk factors for shoulder dystocia. Shoulder dystocia occurred in 57 (2.7%) of the 2118 women included. In the whole cohort, women with shoulder dystocia more often had a history of shoulder dystocia (3.5% vs. 0.2%, p = 0.01), and there was a significant interaction between aOVD and gestational age and the duration of the second stage of labor: women with shoulder dystocia more often had a gestational age > 40 weeks and a second stage of labor longer than 3 h specifically for midpelvic aOVD. In multivariable analysis, a history of shoulder dystocia was the only factor independently associated with shoulder dystocia following aOVD (aOR 27.00, 95% CI 4.10-178.00). The AUC for the receiver operating characteristic curve generated using a multivariate model with term interaction with head station was 0.70 (95% CI 0.62-0.77). The model failed to accurately predict shoulder dystocia.

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.

Evaluation of Suzor forceps training by studying obstetric anal sphincter injuries: a retrospective study

BACKGROUND

Instrumental deliveries are an unavoidable part of obstetric practice. Dedicated training is needed for each instrument. To identify when a trainee resident can be entrusted with instrumental deliveries by Suzor forceps by studying obstetric anal sphincter injuries.

METHODS

A French retrospective observational study of obstetric anal sphincter injuries due to Suzor forceps deliveries performed by trainee residents was conducted from November 2008 to November 2016 at Limoges University Hospital. Perineal lesion risk factors were studied. Sequential use of a vacuum extractor and then forceps was also analyzed.

RESULTS

Twenty-one residents performed 1530 instrumental deliveries, which included 1164 (76.1%) using forceps and 89 (5.8%) with sequential use of a vacuum extractor and then forceps. Third and fourth degree perineal tears were diagnosed in 82 patients (6.5%). Residents caused fewer obstetric anal sphincter injuries after 23.82 (+/- 0.8) deliveries by forceps (p = 0.0041), or after 2.36 (+/- 0.7) semesters of obstetrical experience (p = 0.0007). No obese patient (body mass index> 30) presented obstetric anal sphincter injuries (p = 0.0013). There were significantly fewer obstetric anal sphincter injuries after performance of episiotomy (p <  0.0001), and more lesions in the case of the occipito-sacral position (p = 0.028). Analysis of sequential instrumentation did not find any additional associated risk.

CONCLUSION

Training in the use of Suzor forceps requires extended mentoring in order to reduce obstetric anal sphincter injuries. A stable level of competence was found after the execution of at least 24 forceps deliveries or after 3 semesters (18 months) of obstetrical experience.

[Macrosomia, shoulder dystocia and elongation of the brachial plexus: what is the role of caesarean section?]

The delivery of a macrosomic infant is associated with a higher risk for maternofoetal complications. Shoulder dystocia is the most feared fetal complication, leading sometimes to a disproportionate use of caesarean section. This study aims to evaluate the interest of preventive caesarean section. We conducted a retrospective study of 400 macrosomic births between February 2010 and December 2012. We also identified cases of infants with shoulder dystocia occurred in 2012 as well as their respective birthweight. Macrosomic infants weighed between 4000g and 4500g in 86.25% of cases and between 4500 and 5000 in 12.25% of cases. Vaginal delivery was performed in 68% of cases. Out of 400 macrosomic births, 9 cases with shoulder dystocia were recorded (2.25%). All of these cases occurred during vaginal delivery. The risk for shoulder dystocia invaginal delivery has increased significantly with the increase in birth weight (p <10-4). The risk for elongation of the brachial plexus was 11 per thousand vaginal deliveries of macrosomic infants. This risk was not correlated with birthweight (p = 0.38). The risk for post-traumatic sequelae was 0.71%. Shoulder dystocia affectd macrosoic infants in 58% of cases. Shoulder dystocia is not a complication exclusively associated with macrosomia. Screening for risky deliveries and increasing training of obstetricians on maneuvers in shoulder dystocia seem to be the best way to avoid complications.

[Management of shoulder dystocia]

OBJECTIVE

The objective of this review is to propose recommendations on the management of shoulder dystocia.

MATERIALS AND METHODS

The PubMed database, the Cochrane Library and the recommendations from the foreign obstetrical societies or colleges have been consulted.

RESULTS

In case of shoulder dystocia, if the obstetrician is not present at delivery, he should be systematically informed as quickly as possible (professional consensus). A third person should also be called for help in order to realize McRoberts maneuver (professional consensus). The patient has to be properly installed in gynecological position (professional consensus). It is recommended not to pull excessively on the fetal head (grade C), do not perform uterine expression (grade C) and do not realize inverse rotation of the fetal head (professional consensus). McRoberts maneuver, with or without a suprapubic pressure, is simple to perform, effective and associated with low morbidity, thus, it is recommended in the first line (grade C). Regarding the maneuvers of the second line, the available data do not suggest the superiority of one maneuver in relation to another (grade C). We proposed an algorithm; however, management should be adapted to the experience of the operator. If the posterior shoulder is engaged, Wood's maneuver should be performed preferentially; if the posterior shoulder is not engaged, delivery of the posterior arm should be performed preferentially (professional consensus). Routine episiotomy is not recommended in shoulder dystocia (professional consensus). Other second intention maneuvers are described. It seems necessary to know at least two maneuvers to perform in case of shoulder dystocia unresolved by the maneuver McRoberts (professional consensus).

CONCLUSION

All physicians and midwives should know and perform obstetric maneuvers if needed quickly but without precipitation.

[Prevention of shoulder dystocia risk factors before delivery]

OBJECTIVE

To determine whether it is possible to prevent the occurrence of risk factors for shoulder dystocia before or during pregnancy.

METHODS

The PubMed database, the Cochrane Library and the recommendations from the French and foreign obstetrical societies or colleges have been consulted. Studied measures were exercise before or during pregnancy, dietary management, and gestational diabetes management in obese and non-obese patients.

RESULTS

No study has proven that the correction of these risk factors (except gestational diabetes) would reduce the risk of shoulder dystocia. In the general population, physical exercise is recommended either before or during pregnancy to reduce the risk of gestational diabetes (physical activity before pregnancy) (grade B), fetal macrosomia (grade C) or maternal weight gain during pregnancy (grade C). No dietary regimen is recommended to reduce these issues (grade B). In overweight or obese (body mass index [BMI]>25), physical activity coupled with dietary management is recommended (grade A) because it reduces fetal macrosomia (EL1). In addition, it allows a modest reduction in maternal weight gain during pregnancy (EL2), but did have an effect on the occurrence of gestational diabetes (EL1). In case of gestational diabetes, diabetes care is recommended (diabetic diet, glucose monitoring, insulin if needed) (grade A) as it reduces the risk of macrosomia and shoulder dystocia (EL1). The recommended weight gain during pregnancy is 11.5 kg to 16 kg for normal BMI patients (grade B). Obese patients should be aware of the importance of controlling their weight gain during pregnancy (professional consensus). It is recommended that patients regain their pre-conception weight, and ideally a BMI between 18 and 25 kg/m(2), 6 months postpartum (grade B) to reduce the risk of gestational diabetes and macrosomia in a subsequent pregnancy (EL2).

CONCLUSION

Physical activity is recommended before and during pregnancy to reduce the occurrence of risk factors for shoulder dystocia. In obese patients, physical activity should be coupled with dietary measures to reduce fetal macrosomia and weight gain during pregnancy.