578: Right instrument, right patient, right time: vacuum and forceps vs. forceps alone

Abstract

Forceps delivery has decreased in frequency due to concerns regarding morbidity and this has lead to clinicians citing a lack of experience and confidence with the instrument. Similarly caution has been urged in the use of sequential instruments (most often vacuum followed by forceps) at the time of operative vaginal delivery due to excessive traction on the fetal head and related poor outcomes. We sought to examine outcomes of deliveries using vacuum followed by forceps with those where forceps was the only instrument applied. This is a secondary analysis of the Genesis Study, a prospective multi-center study, consisting of 2,336 nulliparous patients with a vertex presentation. Morbidity outcomes at operative vaginal delivery were examined and cases of forceps alone were compared with cases where there was sequential use of vacuum followed by a forceps to complete the delivery. Markers of birth injury such as Erbs palsy, cephalohematoma, fetal laceration, facial nerve palsy, fracture of the clavicle, skull or humerus were also examined. There were 864 operative vaginal deliveries carried out in the study cohort. Almost 60% (511/864) were vacuum assisted, while 29% (248/864) were forceps alone, 12% (105/864) of deliveries involved sequential vacuum and forceps. There was an increased risk of anal sphincter injury in those delivered with sequential instruments compared with those needing forceps alone (14% [15/105] vs. 7.7% [19/248]; p=0.05). The rates of shoulder dystocia and PPH were similar in both groups. Infants requiring sequential instruments were more likely to have a cephalohematoma (8.6% [9/105] vs. 0% [0/248]; p<0.001), and laceration to the fetal head (6.7% [7/105] vs. 2.0% [5/248]; p=0.02). There was no difference in the risk of facial nerve palsy, fracture of the clavicle, skull or humerus regardless of whether a forceps or both vacuum and forceps were used. Rates of Apgar <7 at 1 and 5 minutes, arterial cord pH <7.20 and NICU admission were similar among both groups. Deliveries carried out using a vacuum followed by a forceps carry significant morbidity in excess of those requiring forceps alone. In embarking on an operative vaginal birth, the operator should prioritize the appropriate use of a single intervention, including consideration for primary forceps selection or recourse to cesarean delivery.