Reverse Løvset maneuver for shoulder dystocia.

Abstract

Shoulder dystocia is an obstetric emergency associated with fetal morbidity and mortality. Mechanical obstruction and failure of the rotation of the fetal shoulders prevents their descent into the pelvis. Current management strategies work by increasing the relative pelvic diameters, rotating the fetal shoulders into a more favorable pelvic diameter, or by reducing the fetal biacromial diameter. We present the Reverse Løvset maneuver that was initially described in 1948, by the Norwegian obstetrician Jørgen Løvset. It is a powerful internal rotational maneuver that differs from the more widely known maneuvers. It allows for a higher rotational force onto the fetus without increasing the strain on the brachial plexus, fetal long bones or the perineum. The clinician needs to use the hand of which the palm faces the fetal back. The whole hand is inserted into the vagina at the 6 o'clock position and continues along the fetal back until it reaches the posterior axilla. The index and middle fingers then grip the posterior axillary fold in a hook-like grip, avoiding the axillary fossa. The other hand fixates the wrist of the operating hand. As the clinician rotates their upper body away from the arm holding the fetal torso, while holding the operating wrist, elbow and shoulder stable, a rotational force is transferred to the fetal body. The posterior shoulder is rotated so that the fetus moves towards a "belly down" position, simultaneously dislodging the anterior shoulder from behind the maternal symphysis. This "cork screw" like rotation is continued up to 180 degrees until descent of the fetal body is felt. An effective transmission of the rotational force is achieved by the correct grip on the muscularly prominent posterior axillary fold adjacent to the strong and relatively stiff posterior thorax of the fetus.