[Neonatal complications related to shoulder dystocia]

Shoulder Dystocia: A Comprehensive Literature Review on Diagnosis, Prevention, Complications, Prognosis, and Management

The term dystocia refers to labor characterized by a slow progression with delayed rates or even pauses in the dilation of the cervix or the descent of the fetus. Dystocia describes the deviation from the limits that define a normal birth and is often used as a synonym for the term pathological birth. Shoulder dystocia, also known as the manual exit of the shoulders during vaginal delivery on cephalic presentation, is defined as the "failure of the shoulders to spontaneously traverse the pelvis after delivery of the fetal head". This means that obstetric interventions are necessary to deliver the fetus's body after the head has been delivered, as gentle traction has failed. Abnormal labor (dystocia) is expressed and represented in partograms or by the prolongation of the latent phase or by slowing and pausing in the phases of cervical dilatation and fetal descent. While partograms are helpful in visualizing the progress of labor, regular use of them has not been shown to enhance obstetric outcomes considerably, and no partogram has been shown to be superior to others in comparative trials. Dystocia can, therefore, appear in any phase of the evolution of childbirth, so it is necessary to simultaneously assess all the factors that may contribute to its abnormal evolution, that is, the forces exerted, the weight, the shape, the presentation and position of the fetus, the integrity and morphology of the pelvis, and its relation to the fetus. When this complication occurs, it can result in an increased incidence of maternal morbidity, as well as an increased incidence of neonatal morbidity and mortality. Although several risk factors are associated with shoulder dystocia, it has proven impossible to recognize individual cases of shoulder dystocia in practice before they occur during labor. Various guidelines have been published for the management of shoulder dystocia, with the primary goal of educating the obstetrician and midwife on the importance of a preplanned sequence of maneuvers, thereby reducing maternal and neonatal morbidity and mortality.

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.

Obstetrics injuries during shoulder dystocia in a tertiary perinatal center

OBJECTIVES

This study will present our results in management of fetal shoulder dystocia with special consideration of maternal and neonatal outcome.

STUDY DESIGN

A retrospective study was performed at a university tertiary perinatal center. The study included data of singleton vaginal term deliveries in the period of 15 years (2006-2020). Analized informations include: obstetrics maternal and neonatal data and outcomes.

RESULTS

This period included 45,687 deliveries with diagnosed shoulder dystocia in 254 (0.7 %) cases in vaginal deliveries. Most of the deliveries were spontaneous births 69.7 %, induced deliveries 30.3 %, 47.2 % primiparas and preexisting or gestational diabetes in 21.7 %. The delivery was managed by vacuum extraction in 13.8 %, mediolateral episiotomy in 48.0 % of births, most of the shoulder dystocia were unilateral anterior, while only two cases were diagnosed as more difficult bilateral and 5 cases were recurrent. 87.4 % cases were resolved by McRobert's maneuver, 7.8 % by Barnum's 3.9 % by Wood's maneuver and one case was managed by Menticoglou and by Bourgoise-Siegemundin maneuver. 4.3 % injuries were classified as OASIS of III/IV degree, early postpartum hemorrhage due in 1.6 %. 54.3 % of newborns were male sex, 61.0 % of newborns had birth weight of above 4000 g (mean 4071 g). Maximal Apgar scores were atributed to 92.5 % in first and to 97.2 % in fifth minute, one case that requaired resuscitation. Clavicle fracture was found in 9.5 %, humerus fracture in 0.4 %, transient form of Duchenne Erb obstetrics brachial palsy was diagnosed in only in 7.5 % newborns, while we have not found any case of permanent brachial palsy.

CONCLUSIONS

Our results confirmed that strategy of prompt identification of shoulder dystocia accompanied by cessation of axial fetal head traction decrease the risk of brachial plexus strain, injury or tear, while performance of exact obstetrical maneuvers resulted in decanceration of fetal shoulders without permanent obstetrics brachial palsy or cerebral morbidity. We think that our good results corelate with our opinion that the performance of external obstetrical manoeuvres should be done without one minute postpone since efforts should be put in sooner shoulder liberation decreasing the time of fetal hypoxia.

Resuscitation of Term Compromised and Asphyctic Newborns: Better with Intact Umbilical Cord?

The authors hypothesize that particularly severely compromised and asphyctic term infants in need of resuscitation may benefit from delayed umbilical cord clamping (after several minutes). Although evidence is sparse, the underlying pathophysiological mechanisms support this assumption. For this review the authors have analyzed the available research. Based on these data they conclude that it may be unfavorable to immediately clamp the cord of asphyctic newborns (e.g., after shoulder dystocia) although recommended in current guidelines to provide quick neonatological support. Compression of the umbilical cord or thorax obstructs venous flow to the fetus more than arterial flow to the placenta. The fetus is consequently cut off from a supply of oxygenated, venous blood. This may cause not only hypoxemia and consecutive hypoxia during delivery but possibly also hypovolemia. Immediate cord clamping may aggravate the situation of the already compromised newborn, particularly if the cord is cut before the lungs are ventilated. By contrast, delayed cord clamping leads to fetoplacental transfusion of oxygenated venous blood, which may buffer an existing acidosis. Furthermore, it may enhance blood volume by up to 20%, leading to higher levels of various blood components, such as red and white blood cells, thrombocytes, mesenchymal stem cells, immunoglobulins, and iron. In addition, the resulting increase in pulmonary perfusion may compensate for an existing hypoxemia or hypoxia. Early cord clamping before lung perfusion reduces the preload of the left ventricle and hinders the establishment of sufficient circulation. Animal models and clinical trials support this opinion. The authors raise the question whether it would be better to resuscitate compromised newborns with intact umbilical cords. Obstetric and neonatal teams need to work even closer together to improve neonatal outcomes.

Newborn Clavicle Fractures: Does Clavicle Fracture Morphology Affect Brachial Plexus Injury?

BACKGROUND

Newborn clavicle fractures and brachial plexus injuries (BPIs) are rare but serious perinatal complications.

METHODS

The aim of this study was to examine the clinical relationship between the fracture morphology (spiral, oblique, transfer) of clavicle fractures that develop during delivery in newborns and BPI. We retrospectively reviewed all perinatal clavicle fractures diagnosed at our institution over 6 years.

RESULTS

The study included 55 newborn infants with perinatal clavicle fracture. Of these, 60% (n=33) were male. Right-side clavicle fractures were present in 56.4% (n=31) and shoulder dystocia was present in 58.2% (n=32) of the patients. Of the fracture localization of the patients, 85.5% (n=47) (Allman I) and 14.5% (n=8) (Allman II) were lateral. Allman type I fractures were not associated with increased BPI (P>0.05). It was observed that 40% (n=22) of the clavicle fractures were characterized by oblique morphology, 34.5% (n=19) of the fractures by spiral morphology, and 25.5% (n=14) of the fractures by transfer morphology. In all, 41.8% (n=23) of the sample also had BPI. Of the entire sample, 40% (n=22) most frequently showed oblique morphology fractures, whereas the patient group with BPI showed spiral morphology as the most common fracture, at a rate of 52.2% (n=10). After examining the relationship between fracture morphology and BPI, the study determined a statistically significant correlation between spiral and oblique morphology fractures and the development of BPI.

CONCLUSIONS

To our knowledge, our study is the first to examine the relationship between newborn clavicle fracture morphology and BPI. We think that they should be evaluated for increased BPI risk in newborn patients that have clavicle fractures with spiral and oblique morphology.

The Association of Clavicle Fracture With Brachial Plexus Birth Palsy

PURPOSE

Shoulder dystocia is the strongest known risk factor for brachial plexus birth palsy (BPBP). Fractures of the clavicle are known to occur in the setting of shoulder dystocia. It remains unknown whether a clavicle fracture that occurs during a birth delivery with shoulder dystocia increases the risk of BPBP or, alternatively, is protective. The purpose of this study was to use a large, national database to determine whether a clavicle fracture in the setting of shoulder dystocia is associated with an increased or decreased risk of BPBP.

MATERIALS AND METHODS

The 1997 to 2012 Kids' Inpatient Database (KID) was analyzed for this study. International Classification of Diseases, Ninth Revision (ICD-9) codes were used to identify newborns diagnosed with shoulder dystocia and BPBP as well as a concurrent fracture of the clavicle. Newborns with shoulder dystocia were stratified into 2 groups: dystocia without a clavicle fracture and dystocia with a clavicle fracture. Multivariable logistic regression was used to quantify the risk for BPBP among shoulder dystocia subgroups.

RESULTS

The dataset included 5,564,628 sample births extrapolated to 23,385,597 population births over the 16-year study period. A BPBP occurred at a rate of 1.2 per 1,000 births. Shoulder dystocia complicated 18.8% of births with a BPBP. A total of 7.84% of newborns with a BPBP also sustained a clavicle fracture. Births with shoulder dystocia and a clavicle fracture incurred BPBP at a rate similar to that for newborns with shoulder dystocia and no fracture (9.82% vs 11.77%). Shoulder dystocia without a concurrent clavicle fracture was an independent risk factor for BPBP (odds ratio, 112.1; 95% confidence interval, 103.5-121.4). Those with shoulder dystocia and clavicle fracture had a risk for BPBP comparable with those with shoulder dystocia but no fracture (odds ratio, 126.7 vs 112.1).

CONCLUSIONS

This population-level investigation suggests that, among newborns with shoulder dystocia, clavicle fracture is not associated with a significant change in the risk of BPBP.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

[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.