Mathematical modeling of fetal foot growth: use of the Rossavik growth model

Growth of the fetal foot has been monitored by foot length (FL), from 12 to 41 weeks menstrual age in 173 normal Japanese fetuses. Growth curve for this parameter has been determined using a Rossavik growth model [p = c(t)k+s(t)]. R2 value of 98.0% was obtained for FL. Variability analysis indicated some progressive increase in variability with fetal age for this parameter. Variability data were used with the growth curve model to determine standard curve for this parameter. This standard curve provides a superior means for evaluating the normal fetal foot growth in the fetus and for assessing menstrual age in utero.