554: The effect of postgraduate training level on the accuracy of clinically estimated fetal weights

Abstract

accuracy of clinically estimated fetal weights Jamil ElFarra, Susanne Matias-Gomes, Tracy Shevell, Hani Tamim, Paul Bobby Stamford Hospital, Department of Obstetrics and Gynecology, Stamford, CT, American University of Beirut Medical Center, Epidemiology and Biostatistics, Department of Internal Medicine, Beirut, Lebanon OBJECTIVE: To evaluate the effect of postgraduate training level on the accuracy of fetal weight assessment in a cohort of obstetrics and gynecology residents. STUDY DESIGN: A prospective observational study was performed over a 6-month period in 2011. Consecutive cases at 37-42 weeks’ gestation presenting in labor, with premature rupture of membranes, for labor induction or for scheduled cesarean section were studied. The estimated fetal weight (EFW) recorded on admission and the examining resident’s postgraduate year (PGY) were recorded. Comparison was made between the birthweight and EFW. Estimation error was calculated by dividing the absolute value of the EFW-birthweight difference by the birthweight. The association between year of residency and estimation error was analyzed using ANOVA. The sensitivity of clinical exam for detection of large-for-gestational age (LGA) newborns ( 3999g) was compared for each PGY cohort using chi-square test. RESULTS: 600 EFW assessments were recorded by 12 OBGYN residents with 3 residents at each year of training (PGY I-IV). Average maternal age, BMI, parity and gestational age were comparable among the four groups, as were the indications for admission. Overall, mean percent error in estimated fetal weight was 8.0% standard deviation (SD) was 7.6. Mean (SD) percent errors were were 8.3 (7.1), 8.4 (7.7), 8.3 (8.8), and 6.7(6.8) for the PGY I, II, III, and IV cohorts, respectively, with P 0.1on ANOVA. In 70% of cases, clinical estimation fell within 10% of birthweight. 83 newborns were LGA at birth (13.8% incidence). Only 18.1% of these cases were identified by clinical assessment on admission. No differences in detection rate were identified between residents at different PGY levels (p 0.1). CONCLUSION: Higher postgraduate training level does not improve the accuracy of clinical estimation of fetal weights. Clinical assessment appears to provide a reliable estimation of birthweight in the majority of cases.