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 greater than or equal to 90 degrees performed between July 1992 and September 1995 were identified (n = 113). For controls 167 forceps deliveries with rotations of less than or equal to 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 greater than or equal to 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 less than or equal to 45 degrees and in 9.7% with rotations of greater than or equal to 90 degrees. The only permanent injury was a brachial plexus palsy that occurred with a forceps rotation of 45 degrees. Rotations of greater than or equal to 90 degrees were not associated with umbilical arterial acidemia below 7.0 or 7.1 compared with rotations of less than or equal to 45 degrees. Rotations of greater than or equal to 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. CONCLUSIONS: Advanced degrees of forceps rotations do not result in any clinically significant increase in infant or maternal morbidity relative to that encountered with lesser degrees of forceps rotation.