IS THERE A BENEFIT TO EPISIOTOMY AT SPONTANEOUS VAGINAL DELIVERY - A NATURAL EXPERIMENT

OBJECTIVE: Our purpose was to examine the association between maternal vaginal and perineal morbidity and episiotomy performed at spontaneou s vaginal delivery. STUDY DESIGN: We obtained data from 17,483 consecu tive spontaneous vaginal deliveries and compared the yearly rates of e pisiotomy, lacerations, and potential confounders with linear regressi on and stratified analyses. RESULTS: Between 1976 and 1994 the use of episiotomy fell significantly (86.8% to 10.4%, R(2) = 0.92, p = 0.0001 ). This change was associated with a fall in the rate of third- and fo urth-degree lacerations (9.0% to 4.2%, R(2) = 0.59, p = 0.0001) and a rise in the rate of intact perinea (10.3% to 26.5%, R(2) = 0.68, p = 0 .0001) and vaginal lacerations (5.4% to 19.3%, R(2) = 0.77, P = 0.0001 ). These associations held in separate analyses stratified by parity a nd birth weight, except for the subgroup of nulliparous women with mac rosomic infants. CONCLUSION: At our institution a large reduction in t he use of episiotomy in spontaneous vaginal deliveries was associated with a significant reduction in perineal trauma in all groups of women except for nulliparous women with macrosomic infants.