Shoulder dystocia is an obstetric emergency.[3] Initial efforts to release a shoulder typically include: with a woman on her back pushing the legs outward and upward, pushing on the abdomen above the pubic bone.[3] If these are not effective, efforts to manually rotate the baby's shoulders or placing the woman on all fours may be tried.[3][2] Shoulder dystocia occurs in approximately 0.4% to 1.4% of vaginal births.[2] Death as a result of shoulder dystocia is very uncommon.[1]
One characteristic of a minority of shoulder dystocia deliveries is the turtle sign, which involves the retraction of the fetal chin against the mother's perineum after the head is delivered.[5][6] This occurs when the baby's shoulder is obstructed by the maternal pelvis or high in the pelvis.
One complication of shoulder dystocia is damage to the upper brachial plexus nerves. These supply the sensory and motor components of the shoulder, arm, and hands. The ventral roots (motor pathway) are most prone to injury.[citation needed] The cause of injury to the baby is debated,[citation needed] but a probable mechanism is manual stretching of the nerves, which in itself can cause injury.[citation needed] Excess tension may physically tear the nerve roots out from the neonatal spinal column, resulting in total dysfunction.[citation needed]
The steps to treating a shoulder dystocia are outlined by the mnemonic ALARMER:[14]
Ask for help.[2] This involves asking for the help of an obstetrician, anesthesia, and for pediatrics for subsequent resuscitation of the infant that may be needed if the methods below fail;
Typically the procedures are performed in the order listed and the sequence ends whenever a technique is successful.[14] Intentional fracturing of the clavicle, a procedure known as cleidotomy,[15][16] is another possibility at non-operative vaginal delivery prior to Zavanelli's maneuver, or symphysiotomy,[17] both of which are considered extraordinary treatment measures. Pushing on the fundus is not recommended.[1]
Simulation training of health care providers to prevent delays in delivery when a shoulder dystocia presents is useful.[18]
A number of labor positions and maneuvers are sequentially performed in attempt to facilitate delivery. These include:[14]
McRoberts maneuver;[19][20] involves hyperflexing the mother's legs tightly to her abdomen. This widens the pelvis, and flattens the spine in the lower back (lumbar spine). If this maneuver does not succeed, an assistant applies pressure on the lower abdomen (suprapubic pressure), and the delivered head is also gently pulled. The technique is effective in about 42% of cases;
Rubin II or posterior pressure on the anterior shoulder, which would bring the baby into an oblique position with the head somewhat towards the vagina;[22]
Active delivery of the anterior arm
Step 1: Index and middle fingers insertion with the hand opposite the baby's face
Step 2: Baby's head slightly tilted downward with the free hand
Step 3: Two fingers are placed on the humerus like a splint
Step 4: Baby's hand appears under the maternal pubic symphysis, allowing the anterior arm to be delivered
Wood's screw maneuver which leads to turning the anterior shoulder to the posterior and vice versa (somewhat the opposite of Rubin II maneuver);[23]
Jacquemier's maneuver (also called Barnum's maneuver), or delivery of the posterior shoulder first, in which the forearm and hand are identified in the birth canal, and gently pulled;
^Jouatte F, Aitken B, Dufour P, et al. (December 1999).『Diabète antérieur à la grossesse, à propos de 143 observations』[Diabetes before pregnancy, apropos of 143 cases]. Contracept Fertil Sex (in French). 27 (12): 845–52. PMID10676041.
^Murray; McKinney (2006). "Intrapartum Complications Chapter 27)". Foundations of Maternal-Newborn and Women's Health Nursing (Fifth ed.). Saunders Elsevier. p. 697. ISBN978-1-4377-0259-0.
^Royal College of Obstetricians and Gynaecologists (March 2012). "Shoulder Dystocia"(PDF). {{cite journal}}: Cite journal requires |journal= (help)
^"Big Baby". www.nuh.com.sg. National University Hospital. Retrieved 15 December 2022. A local study of shoulder dystocia in Singapore determined that a birth weight above 3.6kg was associated with a 16 times higher risk for shoulder dystocia compared to pregnancies resulting in the delivery of an infant weighing less than 3.6kg.
^Gilstrop, M; Hoffman, MK (December 2016). "An Update on the Acute Management of Shoulder Dystocia". Clinical Obstetrics and Gynecology. 59 (4): 813–819. doi:10.1097/GRF.0000000000000240. PMID27681692.
^Fernandez H, Papiernik E (1990).『Manoeuvre de Zavanelli : application à la rétention de tête dernière au détroit supérieur : à propos d'une observation』[The Zavanelli maneuver: use during breech retention of the head in the birth canal. Apropos of a case]. J Gynecol Obstet Biol Reprod (Paris) (in French). 19 (4): 483–5. PMID2380511.
^O'Shaughnessy MJ (October 1998). "Hysterotomy facilitation of the vaginal delivery of the posterior arm in a case of severe shoulder dystocia". Obstet Gynecol. 92 (4 Pt 2): 693–5. doi:10.1016/S0029-7844(98)00153-7. PMID9764668. S2CID42443502.
