An evaluation of clinical estimation of fetal weight and symphysis fundal distance for detection of SGA infants.

In 58 small for gestational age (SGA) infants and 141 non-SGA infants, the measuring of symphysis fundal distance (SF) was compared with clinical estimation of fetal weight in order to evaluate the efficacy of the two methods of predicting SGA. By regression analyses, the SF curve deviation explains 22% of the variation of birthweight. The estimated fetal weight (EFW) curve deviation explains 40%. By combining the two values, 42% of the variation in birthweight is explained. When receiver operating characteristic (ROC) curve analyses, Kappa index and relative risk were applied the clinical estimation of fetal weight by abdominal palpation was found to be as reliable a predictor of SGA at birth as the measurement of the SF distance. Statistical analyses of the SF curve and EFW curve do not improve the results compared with the last measurement of SF distance and EFW. Combination of the EFW and SF measurements results in a higher sensitivity (one test positive) or a higher predictive value (both tests positive). Only marginal additional diagnostic information was achieved, however, as the ROC curves, Kappa index and Relative risk were nearly unchanged, regardless of combination of EFW and SF measurements.