Shoulder dystocia
Encyclopedia
Shoulder dystocia is a specific case of dystocia
whereby after the delivery of the head, the anterior shoulder
of the infant
cannot pass below the pubic symphysis
, or requires significant manipulation to pass below the pubic symphysis
. It is diagnosed when the shoulders fail to deliver shortly after the fetal head. In shoulder dystocia, it is the chin that presses against the walls of the perineum
. Shoulder dystocia is an obstetrical emergency, and fetal demise can occur if the infant is not delivered, due to compression of the umbilical cord
within the birth canal.
.
More drastic maneuvers include
The advantage of proceeding in the order of ALARMER is that it goes from least to most invasive, thereby reducing harm to the mother in the event that the infant delivers with one of the earlier maneuvers. In the event that these maneuvers are unsuccessful, a skilled obstetrician may attempt some of the additional procedures listed below. Intentional clavicular fracture is a final attempt at nonoperative vaginal delivery prior to Zavanelli's maneuver or symphysiotomy
, both of which are considered extraordinary treatment measures.
, but it is often difficult to predict. Despite appropriate obstetric management, fetal injury (such as brachial plexus injury) or even fetal death can be a complication of this obstetric emergency.
Recurrence rates are relatively high.
nerves. These supply the sensory and motor components of the shoulder, arm and hands. The aetiology of injury to the fetus is debated, but a probable mechanism is manual stretching of the nerves, which in itself can cause injury. Furthermore, excess tension may physically tear the nerve roots out from the neonatal spinal column, resulting in total dysfunction. The ventral roots (motor pathway) are most prone to injury, as they are in the plane of greatest tension (anterior, sensory nerves are somewhat protected due to the usual inward movement of the shoulder).
Dystocia
Dystocia is an abnormal or difficult childbirth or labour. Approximately one fifth of human labours have dystocia.Dystocia may arise due to incoordinate uterine activity, abnormal fetal lie or presentation, absolute or relative cephalopelvic disproportion, or a massive fetal tumor such as a...
whereby after the delivery of the head, the anterior shoulder
Shoulder
The human shoulder is made up of three bones: the clavicle , the scapula , and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The major joint of the shoulder is the glenohumeral joint, which...
of the infant
Infant
A newborn or baby is the very young offspring of a human or other mammal. A newborn is an infant who is within hours, days, or up to a few weeks from birth. In medical contexts, newborn or neonate refers to an infant in the first 28 days after birth...
cannot pass below the pubic symphysis
Pubic symphysis
The pubic symphysis or symphysis pubis is the midline cartilaginous joint uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis...
, or requires significant manipulation to pass below the pubic symphysis
Pubic symphysis
The pubic symphysis or symphysis pubis is the midline cartilaginous joint uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis...
. It is diagnosed when the shoulders fail to deliver shortly after the fetal head. In shoulder dystocia, it is the chin that presses against the walls of the perineum
Perineum
In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
. Shoulder dystocia is an obstetrical emergency, and fetal demise can occur if the infant is not delivered, due to compression of the umbilical cord
Umbilical cord
In placental mammals, the umbilical cord is the connecting cord from the developing embryo or fetus to the placenta...
within the birth canal.
Signs
One often described feature is the turtle sign, which involves the appearance and retraction of the fetal head (analogous to a turtle withdrawing into its shell), and the erythematous (red), puffy face indicative of facial flushing. This occurs when the baby's shoulder is obstructed by the maternal pelvisPelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
.
Procedures
A number of labor positions and/or obstetrical maneuvers are sequentially performed in attempt to facilitate delivery at this point, including :- McRoberts maneuverMcRoberts maneuverThe McRoberts maneuver is employed in case of shoulder dystocia during childbirth and involves hyperflexing the mother's legs tightly to her abdomen. This widens the pelvis, and flattens the spine in the lower back . If this maneuver does not succeed, an assistant applies pressure on the lower...
; The McRoberts maneuver is employed in case of shoulder dystocia during childbirth and 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
- suprapubic pressure (or Rubin I)
- Rubin II or posterior pressure on the anterior shoulderAnterior shoulderAnterior shoulder in obstetrics refers to that shoulder of the fetus that faces the pubic symphysis of the mother during delivery. Depending upon the original position of the fetus, either the left or the right shoulder can be the anterior shoulder. It is known as the anterior shoulder as it faces...
, which would bring the fetus in an oblique position with head somewhat towards the vagina
- Woods' screw maneuverWoods' screw maneuverWoods' screw maneuver is practiced in obstetrics when dealing with shoulder dystocia—a condition in which the fetal shoulders cannot easily pass through the vagina...
which leads to turning the anterior shoulder to the posterior and vice versa (somewhat the opposite of Rubin II maneuver)
- Jacquemier's maneuver (also called Barnum's maneuver), or delivery of the posterior shoulderPosterior shoulderPosterior shoulder in obstetrics refers to the shoulder of the fetus other than the anterior shoulder. Thus, the posterior shoulder faces the rectum of the mother during delivery. Whether left or the right shoulder becomes the posterior shoulder is dependent upon the original position of the fetus....
first, in which the forearm and hand are identified in the birth canal, and gently pulled.
- Gaskin maneuver, named after Certified Professional Midwife, Ina May GaskinIna May GaskinIna May Gaskin, CPM, has been described as "the mother of authentic midwifery."-Family:Gaskin was born to an Iowa Protestant family . Her father, Talford Middleton, was raised on a large Iowa farm, which was lost to a bank not long after his father’s accidental death in 1926...
, involves moving the mother to an all fours position with the back arched, widening the pelvic outlet.
More drastic maneuvers include
- Zavanelli's maneuver, which involves pushing the fetal head back in with performing a cesarean section. or internal cephalic replacement followed by Cesarean section
- intentional fetal clavicular fracture, which reduces the diameter of the shoulder girdle that requires to pass through the birth canal.
- maternal symphysiotomySymphysiotomySymphysiotomy is a surgical procedure in which the cartilage of the pubic symphysis is divided to widen the pelvis allowing childbirth when there is a mechanical problem.- Introduction :...
, which makes the opening of the birth canal laxer by breaking the connective tissue between the two pubesPubis (bone)In vertebrates, the pubic bone is the ventral and anterior of the three principal bones composing either half of the pelvis.It is covered by a layer of fat, which is covered by the mons pubis....
bones facilitating the passage of the shoulders.
- abdominal rescue, described by O'Shaughnessy, where a hysterotomyHysterotomyA hysterotomy is an incision in the uterus, commonly combined with a laparotomy during a caesarean section. Hysterotomies are also performed during fetal surgery....
facilitates vaginal delivery of the impacted shoulder
Management
Management of shoulder dystocia has become a focus point for many obstetrical nursing units in North America. Courses such as the Canadian More-OB program encourage nursing units to do routine drills to prevent delays in delivery which adversely affect both mother and fetus. A common treatment mnemonic is ALARMER- Ask for help. This involves requesting the help of an obstetrician, anesthesia and pediatrics for subsequent resuscitation of the infant.
- Leg hyperflexion (McRoberts' maneuver)
- Anterior shoulder disimpaction (suprapubic pressure)
- Rubin maneuver
- Manual delivery of posterior arm
- Episiotomy
- Roll over on all fours
The advantage of proceeding in the order of ALARMER is that it goes from least to most invasive, thereby reducing harm to the mother in the event that the infant delivers with one of the earlier maneuvers. In the event that these maneuvers are unsuccessful, a skilled obstetrician may attempt some of the additional procedures listed below. Intentional clavicular fracture is a final attempt at nonoperative vaginal delivery prior to Zavanelli's maneuver or symphysiotomy
Symphysiotomy
Symphysiotomy is a surgical procedure in which the cartilage of the pubic symphysis is divided to widen the pelvis allowing childbirth when there is a mechanical problem.- Introduction :...
, both of which are considered extraordinary treatment measures.
Risk factors
Although the definition is imprecise, it occurs in approximately 1% of vaginal births. There are well-recognised risk factors, such as diabetes, fetal macrosomia, and maternal obesityMaternal obesity
Maternal obesity refers to obesity of a woman during pregnancy. Parental obesity refers to obesity of either parent during pregnancy....
, but it is often difficult to predict. Despite appropriate obstetric management, fetal injury (such as brachial plexus injury) or even fetal death can be a complication of this obstetric emergency.
Recurrence rates are relatively high.
Complications
The major concern of shoulder dystocia is damage to the upper brachial plexusBrachial plexus
The brachial plexus is a network of nerve fibers, running from the spine, formed by the ventral rami of the lower four cervical and first thoracic nerve roots...
nerves. These supply the sensory and motor components of the shoulder, arm and hands. The aetiology of injury to the fetus is debated, but a probable mechanism is manual stretching of the nerves, which in itself can cause injury. Furthermore, excess tension may physically tear the nerve roots out from the neonatal spinal column, resulting in total dysfunction. The ventral roots (motor pathway) are most prone to injury, as they are in the plane of greatest tension (anterior, sensory nerves are somewhat protected due to the usual inward movement of the shoulder).
- Klumpke paralysisKlumpke paralysisNamed after Augusta Déjerine-Klumpke, Klumpke's paralysis is a variety of partial palsy of the lower roots of the brachial plexus. The brachial plexus is a network of spinal nerves that originates in the back of the neck, extends through the axilla , and gives rise to nerves to the upper limb...
- Erb's PalsyErb's palsyErb's palsy is a paralysis of the arm caused by injury to the upper group of the arm's main nerves, specifically the upper trunk C5-C6 is severed. These form part of the brachial plexus, comprising the ventral rami of spinal nerves C5-C8, and T1. These injuries arise most commonly, but not...
- Fetal hypoxiaIntrauterine hypoxiaIntrauterine hypoxia occur when the fetus is deprived of an adequate supply of oxygen. IH is used to describe inadequate oxygen availability during the gestation period, birth asphyxia can result from inadequate supply of oxygen immediately prior to, during or just after delivery...
- Fetal deathPerinatal mortalityPerinatal mortality , also perinatal death, refers to the death of a fetus or neonate and is the basis to calculate the perinatal mortality rate. Variations in the precise definition of the perinatal mortality exist specifically concerning the issue of inclusion or exclusion of early fetal and...
- Cerebral palsyCerebral palsyCerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
- Fetal death
- Maternal post partum hemorrhageObstetrical hemorrhageObstetrical hemorrhage refers to heavy bleeding during pregnancy, labor, or the puerperium. Bleeding may be vaginal and external, or, less commonly but more dangerously, internal, into the abdominal cavity...