MATHEMATICAL-MODELING OF FETAL ORGAN GROWTH USING THE ROSSAVIK GROWTH-MODEL .4. LUNG

Growth of the fetal lung has been monitored by left lung area (LLA), r ight lung area (RLA), and total lung area (TLA) from 14 to 41 weeks me nstrual age in 116 normal Japanese fetuses. Growth of the fetal heart and chest has also been monitored by heart area (HA) and chest area (C A), respectively. Growth curves for these parameters have been determi ned by using a Rossavik growth model [p = c(t)(k+s(t))]. R(2) values o f 95.3%, 90.3%, 89.0%, 88.7%, and 92.1% were obtained for CA, HA, LLA, RLA, and TLA, respectively. Variability analysis indicated a progress ive increase in variability with fetal age for these five parameters. Variability data were used with the growth curve models to determine s tandard curves for these parameters. These standard curves provide a s uperior means for evaluating the normal fetal lung growth in the fetus and for identifying pulmonary hypoplasia in utero.