Peripartum estimated blood loss: Effects of perineal laceration

Abstract

IRENE STAFFORD, GARY DILDY, STEVEN CLARK, MICHAEL BELFORT, Louisiana State University Medical Center at New Orleans, Obstetrics & Gynecology, New Orleans, Louisiana, St Mark’s Hospital, Maternal-Fetal Medicine, Salt Lake City, Utah OBJECTIVE: The purpose of our study is to examine trends in blood loss according to degree of perineal laceration, comparing visual estimated blood loss (vEBL) with calculated estimated blood loss (cEBL) in vaginal deliveries. STUDY DESIGN: Between January 1 and September 2 of 2005, there were 876 deliveries on the LSU obstetrical service at University Hospital. After excluding those with blood transfusions, 677 who had height/weight and preand post-delivery hematocrit (HCT) data were analyzed. Of the 446 women who underwent vaginal delivery, 290 had no lacerations (L0), 72 had first degree lacerations (L1), 78 had second degree lacerations (L2) and 6 had either a third or fourth degree lacerations (L3-4). vEBL was recorded in mL by the physician present at delivery. cEBL was derived by multiplying the calculated pregnancy blood volume (0.75 ! {[Maternal height in inches ! 50]+ [Maternal weight in pounds ! 25]}) by percent of blood volume lost ({pre-delivery HCT – post-delivery HCT}/pre-delivery HCT). Statistitical analysis was accomplished using the Wilcoxon signed-rank test and the Kruskal-Wallis test with a P-value of less than .05 considered significant RESULTS: The median vEBL for L0, L1, L2, L3-4 was 200, 250, 300 and 350 mL respectively. The median cEBL for these groups was 519, 604, 764 and 932 mL respectively. Box plots in the figure illustrate 10, 25, 50, 75, and 90th percentile for each group. The median difference between vEBL and cEBL for L0, L1, L2, L3-4 was 259, 343, 460 and 582 mL respectively.