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
A number of obstetrical maneuvers are sequentially performed in attempt to facilitate delivery at this point, including :
- Gaskin maneuver, named after Certified Professional Midwife, Ina May Gaskin, involves moving the mother to an all fours position with the back arched, widening the pelvic outlet.
- McRobert's maneuver;
- suprapubic pressure (or Rubin I)
- Rubin II or posterior pressure on the anterior shoulder, which would bring the fetus in an oblique position with head somewhat towards the vagina
- Woods' screw maneuver 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 shoulder first, in which the forearm and hand are identified in the birth canal, and gently pulled.
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 clavicular fracture, which reduces the diameter of the shoulder girdle that requires to pass through the birth canal.
- symphisiotomy, which makes the opening of the birth canal laxer by breaking the connective tissue between the two pubes bones facilitating the passage of the shoulders.
- abdominal rescue, described by O'Shaughnessy, where a hysterotomy facilitates vaginal delivery of the impacted shoulder
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 obesity
, 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 and low most of the short time.