LETTERS.

Don't Squeeze!

Women in labor may be setting themselves up for shoulder dystocia if they fight the urge to defecate or pass wind.

During the second stage of labor the vagina dilates enormously, and the disposition of the pelvic floor and the viscera is altered. The structures in the anterior section of the pelvis become drawn upward and forward. The posterior section is displaced downward and backward so that the fetus can be expelled through the open space.

The bladder is drawn up above the symphysis pubis and into the abdomen. The urethra becomes correspondingly elongated. Failure of the bladder to ascend could contribute to impaction of the anterior shoulder above the symphysis.

During defecation, urination, and parturition, the levator ani muscle is relaxed and the pelvic hiatus is widened. During squeezing, coughing, or vomiting, the pelvic hiatus is sealed and becomes tight.

Laboring women often get a sensation or desire to defecate or pass wind. To avoid embarrassment some women may squeeze during restitution, inhibiting external rotation. Levator contraction, once initiated, may be sustained in a spastic state.

The levator ani is relaxed in the squat ting position, and this is certainly the best treatment for this condition; the McRoberts maneuver is second best. Vaginal manipulations are generally useful in the less severe cases, but their success depends on the experience of the attendant.