The role of forceps rotation in maternal and neonatal injury

OBJECTIVE: Our purpose was to assess the impact of forceps rotation on maternal and neonatal injury. STUDY DESIGN: In this retrospective case- controlled study performed at the University of Texas Medical Branch at Galveston all forceps deliveries with a rotation of ≥90 degrees performed between July 1992 and September 1995 were identified (n = 113). For controls 167 forceps deliveries with rotations of ≤45 degrees were randomly selected. Control deliveries occurred during the same time period and were matched to within 2 weeks of gestational age as well as to nulliparous versus parous status. The majority of deliveries were low; however, some midforceps deliveries were also included. RESULTS: Forceps rotations of ≥90 degrees accounted for 0.8% of all deliveries. A major fetal injury, defined as a skull fracture, subdural hematoma, brachial plexus or a sixth or seventh cranial nerve injury, occurred in 10.2% of deliveries with rotations of ≤45 degrees and in 9.7% with rotations of ≥90 degrees. The only permanent injury was a brachial plexus palsy that occurred with a forceps rotation of 45 degrees. Rotations of ≥90 degrees were not associated with umbilical arterial acidemia below 7.0 or 7.1 compared with rotations of ≤45 degrees. Rotations of ≥90 degrees were associated with longer maternal hospital stays (P = .009). Neither lacerations of the birth canal, third- or fourth-degree episiotomies, or fall in the maternal hematocrit correlated with the degree of forceps rotation.