Maternal estimation of fetal weight as a complementary method of fetal weight assessment: A prospective clinical trial

OBJECTIVE: To assess the accuracy of fetal weight estimations performed by parturients vs. clinical and sonographic estimates. STUDY DESIGN: Term parous women were included in this prospective trial. Each woman estimated the weight of her fetus. Fetal weight was also estimated sonographically and clinically. The clinical evaluations were performed by an attending gynecologist and a resident. Estimate accuracy for extreme fetal weights was evaluated separately. RESULTS: We enrolled 128 women. Maternal and resident estimations' accuracy was identical. The attending physician estimates were superior to the residents' and parturients', with a mean absolute error of 318 g and 67% of the evaluations within the 10% boundaries of the actual birth weight. Sonographic evaluation was the most accurate method, with a mean absolute error of 244 g and 76% of evaluations within 10% of the actual birth weight. When partitioned to extreme fetal weight groups (upper and lower 10th percentiles), the maternal evaluation was at least as accurate as the clinical evaluations of both the attending and resident. CONCLUSION: Maternal evaluation of the fetus's weight is as accurate as physicians' clinical estimations, and is advised as a complementary method of assessment. This estimation may have greater relevance when intrauterine growth restriction or macrosomia is suspected.