Use of advanced degrees of forceps rotation compares favorably with cesarean delivery in terms of morbidity. The increased morbidity with forceps delivery has been found to stem principally from maternal injuries, such as vaginal and sphincter lacerations, urinary retention and vulvovaginal hematomas. However, there are reports of catastrophic neonatal injuries as a result of forceps rotation. It is not known whether these injuries are a result of mismanagement or a rare result of properly performed forceps rotation. To investigate this issue, Hankins and associates conducted a retrospective study of the occurrence of maternal and neonatal injury after forceps rotation of 90 degrees or more.
The authors reviewed the medical records of 113 deliveries in which forceps rotation of 90 degrees or more was performed. These cases were compared with 167 deliveries in which forceps rotation of 45 degrees or less was required. The two groups were matched for gestational age and parity. The 280 forceps deliveries were among 13,799 deliveries from July 1992 to September 1995 at a teaching hospital. Forceps rotation of 45 degrees or less was always accomplished with the use of classic forceps, whereas all rotations of 90 degrees or more were performed with Kielland's forceps.
In both groups, the primary indication for operative vaginal delivery was to conclude the second stage of labor because it was prolonged or because maternal fatigue and ineffective pushing or a medical indication necessitated shortening of the second stage. Fetal heart rate abnormalities were an indication for forceps rotation of 45 degrees or less in 24 percent of the cases, compared with 17 percent of the deliveries in which forceps rotation was 90 degrees or more. Birth weights were similar in both groups.
As far as maternal outcome was considered, the mean length of hospital stay was 2.2 days in the group that required forceps rotation of 90 degrees or more, compared with a mean hospitalization of 1.7 days in the group that required forceps rotation of 45 degrees or less. The mean drop in hematocrit was 1 percent greater in the group undergoing the more advanced degrees of forceps rotation. The occurrence of vaginal lacerations or a third- or fourth-degree episiotomy was independent of the degree of forceps rotation.
With regard to neonatal injury, major trauma occurred in 17 (10.2 percent) of the infants who required forceps rotation of 45 degrees or less and in 11 (9.7 percent) of the infants who required forceps rotation of 90 degrees or more. Major trauma was defined as cranial nerve or brachial plexus palsy, a skull fracture or intracranial hemorrhage. The only permanent injury was a brachial plexus palsy that occurred with a forceps rotation of 45 degrees and subsequent shoulder dystocia.
Most of the neonatal injuries were in the form of a cephalohematoma, bruising or forceps marks, or superficial lacerations not requiring repair. Cephalohematomas developed in nine (8.0 percent) of the infants who required forceps rotation of 90 degrees or more and in 16 (11.4 percent) of the infants who required forceps rotation of 45 degrees or less. Bruising or forceps marks were present in 23 (13.8 percent) of the infants in the 45-degrees-or-less rotation group; seven (6.2 percent) of the infants in the other group sustained these injuries.
Compared with forceps rotation of 45 degrees or less, forceps rotation of 90 degrees or more was not associated with an increased incidence of acidemia (umbilical arterial pH of below 7.0 or 7.1). No difference was noted between the two groups in the percentage of neonates with Apgar scores of less than 7 at five minutes.
The authors conclude that maternal morbidity is not significantly increased by advanced degrees of forceps rotation. Maternal outcome was excellent in this series of patients. Similarly, neonatal outcome was good, with no long-term sequelae among infants who required 90 degrees or more of forceps rotation for delivery. The authors state that a role for advanced forceps rotation exists. Although neonatal morbidity did occur, it was not increased in infants undergoing forceps rotation of 90 degrees or more.