Errors of presentation

Errors of presentation during labor result in increased maternal and fetal morbidity and mortality and therefore deserve attention. For the purpose of this study, breech presentation is not included, and the errors discussed will include face, brow, compound, and shoulder presentations. When these problems are promptly diagnosed and properly managed, better results for mother and baby are obtained. A summary of the important etiological factors concerned in the study of the group includes such maternal factors as pelvic contraction, large pelvis, multiparity, lax abdominal wall, congenital anomalies of the uterus, placenta previa, and pelvic tumor. Fetal factors include prematurity, large infant, macerated fetus, multiple pregnancy, abnormality of the fetal neck, nuchal cord, and congenital anomalies. It is important to realize that upon diagnosing an error of presentation, possible etiological factors must immediately be investigated. Consideration of these factors may prevent errors in management and resultant tragedy. Early diagnosis is important since it determines management. Failure to make a prompt diagnosis of an error of presentation may predispose to uterine inertia which could result in prolonged labor with increased maternal and fetal morbidity. The usual means of diagnosis are abdominal, rectal, vaginal, and x-ray examinations. Despite careful abdominal examination during pregnancy, few errors except shoulder presentation are detected before labor starts. The most valuable diagnostic method is a careful vaginal examination in labor. It is frequently desirable to confirm a clinical diagnosis of an error of presentation radiologically, and, at the same time, to obtain additional information as to pelvic capacity, placental position, and possible fetal anomaly. However, abnormal presentation is often first diagnosed on x-ray in the presence of polyhydramnios or multiple pregnancy. The method of treatment depends on the type of error that is diagnosed, the etiological factor or factors involved, the condition of the mother and infant at the time the diagnosis is made, the experience of the operator, and the facilities at hand.