Background: Episiotomies are the most frequently performed surgical procedure among United States women, but there are no published epidemiological studies of the extent of variation in episiotomy use among different obstetrical providers, or the outcomes associated with different levels of use. The objective of this study was to assess the extent of hospital variation in the use of episiotomy and the relationship between hospital episiotomy use and the incidence and risk of perineal trauma among women residing in a large urban area in the United States.
Methods: Linked birth certificate and hospital discharge data pertaining to births to nulliparous women without prolonged labor or obstructed deliveries, and with infants weighing between 2500 and 4000 g, were analyzed for 18 major maternity hospitals. The relationship between episiotomy use and perineal trauma at the hospital level was examined using regression analysis.
Results: Hospital episiotomy rates ranged from approximately 20 to 73 percent. The rate of third or fourth degree perineal lacerations varied from a low of 4 percent to a high of more than 13 percent among hospitals. Rates of episiotomy were significantly correlated with rates of a third or fourth degree perineal laceration (r = 0.70; p < 0.01), and with the hospital-specific, adjusted odds ratios for such lacerations (r = 0.65; p < 0.01).
Conclusions: Findings from the analysis of epidemiological data for this study population were consistent with those from clinical studies, indicating that liberal as opposed to restrictive use of episiotomy is unwarranted, and probably even harmful. Hospital episiotomy rates exceeded 20 percent in all cases, but such rates appear difficult to justify in face of the evidence.