We conducted a prospective observational study of 134 vacuum extraction-assisted deliveries at Olive View-UCLA Medical Center in 1995. Data collected included parity, gestational age, duration of first and second stages of labor, indication for operative delivery, station and position of fetal head, duration of vacuum application, number of "pop-offs," neonatal weight, and descriptions of scalp marks or injury. Cranial imaging studies were obtained if clinically indicated.