Fetal biometry: A comparison of family physicians and radiologists

Background and Objectives: While performance and reading of obstetric sonog rams is a skill widely taught in family practice residency programs, no pri or studies have compared ultrasound performance and interpretation in resid ency programs with that of hospital radiologists. This study compares resul ts of fetal biometry for gestational age determination performed sequential ly by faculty-supervised residents and radiologists. Methods: This retrospe ctive chart review selected cases from among all gravidas who had ultrasoun d performed in a family practice residency clinic between January 1992 and April 1999. Biometry was performed by residents tinder the supervision of f aculty preceptors who had ultrasound training and experience. A patient was included if (1) results of both a family practice ultrasound and a radiolo gist-read hospital ultrasound were present in the chart, (2) both studies w ere done before 36 weeks gestation, and (3) the family practice examination preceded the hospital study. The difference in expected date of confinemen t between resident and radiologist ultrasound was calculated, and this diff erence was evaluated for statistical significance by a paired sample t test . Results: Ninety-two ultrasound pairs were assessed, a sample size that pr ovided .90 power to detect a gestational age estimate difference of 3 days between family practice and radiologist interpretations. The normally distr ibuted observed mean difference in gestational age estimates was only 1.5 d ays. Conclusions: This study found no difference in gestational age assessm ent performed by closely supervised family practice residents in comparison to radiologists.