Intrapartum prediction of macrosomia: Accuracy of abdominal circumference estimation

Objective: To evaluate the accuracy of abdominal circumference (AC) estimat ion of macrosomia early in labor and whether a cutoff value could be detect ed. Design: A prospective clinical trial. Setting: The Department of Obstet rics and Gynecology, Cairo University. Participants: One hundred pregnant f emales presenting in early labor with clinical impression of macrosomia wer e examined by ultrasound, and those babies with abdominal circumference mor e or equal to 35 cm were recruited for the study. Interventions: Every woma n was considered as her own control, and fetal weight was calculated using the formula of Shepard et al. The accuracy of abdominal circumference in pr ediction of macrosomia was evaluated using the Receiver operating character istic curve. Results: A cutoff value of AC greater than or equal to 37 cm w as found to have a sensitivity of 77%, a specificity of 75%, a positive lik elihood ratio of 3.1 and a negative likelihood ratio of 0.3. Conclusion: In trapartum ultrasonographic evaluation of abdominal circumference for suspec ted macrosomic babies in early labor is an easy, practical method that shou ld be adopted in decision making. Copyright (C) 2001 S. Karger AG,Basel.