The development and use of a standard symphysial-fundal height growth curve in the prediction of small for gestational age neonates

The symphysial-fundal height (SF) measurement has been routinely used in obstetrics, although its value in the prediction of small-for-gestational-age (SGA) infants remains controversial. A retrospective study was performed in order to assess the sensitivity and specificity of the SF distance and establish guidelines for its use. Local neonatal birthweight distribution and SF growth curves were developed. Eighty-six percent of 28 SGA infants demonstrated one measurement under - 1 S.D. of the mean SF growth curve as did 36% of appropriate for gestational age (AGA) neonates. Seventy-five percent of SGA infants subsequently demonstrated a second measurement below - 1 S.D. of the mean curve, 90% prior to 36 weeks. Only 16% of AGA exhibited such a SF growth pattern. A protocol for maximizing the use of this inexpensive and easily obtained parameter is proposed.