Shoulder dystocia is a serious obstetric complication, where one or both shoulders of a child are trapped after the head is born during vaginal delivery. The situation is life-threatening for the child and requires quick management with obstetric manoeuveres for delivering the shoulders. Rarely, the abdominal approach called Zavanelli manoeuvre is used to achieve delivery after a replacement of the head back in the birth canal, prior to acute caesarean section. This is a case report of a 26-year-old woman with severe shoulder dystocia, failed Zavanelli manoeuvre and vaginal delivery of a lifeless child.

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.

The Zavanelli manoeuvre is often the final resort of the clinician facing undeliverable shoulder dystocia and we present retrospective pooled data comprising 110 shoulder dystocia cases, 11 impacted breech and 11 locked twin deliveries assessed from ten case series and 38 individual case reports. Although recommended when other external and internal manipulations have failed, we suspect that many clinicians have not had formal training on how to conduct the manoeuvre and may be unfamiliar with the steps involved, leading to a reluctance and delay in initiating this. We describe original descriptions of the manoeuvre, examine its use in intractable shoulder dystocia and illustrate stepwise the cephalic replacement technique. For this review, we have concentrated mainly on the outcomes of the Zavanelli manoeuvre in shoulder dystocia but have also touched on its role in impacted breech and locked twin deliveries. Lastly, we discuss the cognitive load an obstetrician faces when having to make time critical decisions in severe shoulder dystocia and share how other disciplines train and prepare their personnel to manage similar rare and unexpected scenarios.

Since its first description in 1980, the Zavanelli maneuver - reintroduction of the fetus in the uterus after failure of maneuver to reduce shoulder dystocia - remains an extraordinary and nearly unknown remedy. We report a Zavanelli maneuver performed in a case of irreducible raising arm of a fetus in breech presentation. Literature and our observation indicate that fetal and neonatal prognosis in Zavanelli maneuver is pretty good if breech presentation. This exceptional situation should remain in mind of obstetricians.

The exact role of the Zavanelli maneuver for the management of shoulder dystocia still remains to be defined. None of the previously reported cases in which the Zavanelli maneuver has been employed described impaction of posterior fetal arm. At 40 weeks' gestation, a nulliparous patient with gestational diabetes, who underwent vacuum delivery, delivered an infant with shoulder dystocia. McRoberts' maneuver, suprapubic pressure, midline episiotomy, and Woods' maneuver were all unsuccessful in alleviating the shoulder dystocia. The posterior fetal arm was noted to be persistently impacted, so the Zavanelli maneuver was used to deliver an unsuspected macrosomic (4215 g) infant. The newborn, at the age of 3 years, has a right Erb's palsy. The Zavanelli maneuver can be used to alleviate a posterior arm shoulder dystocia, though there may be concomitant neurological injury.

In a primipara, 28 years of age and with a BMI of 44 kg/m2, a Zavanelli manoeuvre was performed. Due to uterine atony she had to undergo a hysterectomy. A multipara, 39 years of age and with a BMI of 66 kg/m2, experienced that her weight exceeded the limits of the beds and that local anaesthesia was hard to perform; she suffered from a lesion of the lumbosacral plexus caused by a shoulder dystocia. In the end, both mothers and their babies could go home in a moderate condition. Obesity is becoming more prevalent and brings with it an increase in obstetric risks. During pregnancy and delivery, morbidly obese patients should be monitored by a gynaecologist. Special interest should focus on screening for (gestational) diabetes, hypertension and foetal growth. Ultrasound may detect congenital malformations early; however, the sensitivity of ultrasound is lower in morbidly obese patients. When macrosomia is expected, a clear plan should be made regarding the mode of delivery. It is useful to make a treatment protocol for morbidly obese patients.

Shoulder dystocia can be one of the most frightening emergencies in the delivery room. Although many factors have been associated with shoulder dystocia, most cases occur with no warning. Calm and effective management of this emergency is possible with recognition of the impaction and institution of specified maneuvers, such as the McRoberts maneuver, suprapubic pressure, internal rotation, or removal of the posterior arm, to relieve the impacted shoulder and allow for spontaneous delivery of the infant. The "HELPERR" mnemonic from the Advanced Life Support in Obstetrics course can be a useful tool for addressing this emergency. Although no ideal manipulation or treatment exists, all maneuvers in the HELPERR mnemonic aid physicians in completing one of three actions: enlarging the maternal pelvis through cephalad rotation of the symphysis and flattening of the sacrum; collapsing the fetal shoulder width; or altering the orientation of the longitudinal axis of the fetus to the plane of the obstruction. In rare cases in which these interventions are unsuccessful, additional management options, such as intentional clavicle fracture, symphysiotomy, and the Zavanelli maneuver, are described.

Several reports describe the replacement of the partially delivered fetus into the vagina followed by Cesarean section after failed vaginal delivery. Undeliverable shoulder dystocia is by far the most common cause of failed vaginal delivery. The objective of this report was to review the safety and to reconsider when to perform the Zavanelli maneuver in the management of shoulder dystocia. We report two cases of severe shoulder dystocia in which commonly recommended therapeutic options failed. Cephalic replacement was performed with ease followed by Cesarean section. Endometritis was the maternal complication in both cases. Both infants had transient Erb's palsy. Although traditionally the Zavanelli maneuver is a method of last resort in the management of shoulder dystocia, consideration should be given to its use earlier in the treatment of obstructed vaginal delivery.