Reverse Løvset maneuver for shoulder dystocia

Shoulder dystocia is an obstetrical emergency associated with fetal morbidity and mortality. Mechanical obstruction and failure of fetal shoulder rotation prevent 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. This study presents the reverse Løvset maneuver that was initially described in 1948 by the Norwegian obstetrician Jørgen Løvset. This 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 perineum. The clinician needs to use the hand with the palm facing 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 grip the posterior axillary fold in a hooklike 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 toward a "belly-down" position, simultaneously dislodging the anterior shoulder from behind the maternal symphysis. This "corkscrew"-like rotation is continued up to 180° 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.