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Mathematical Modeling of Fetal Growth: II. Head Cube (A), Abdominal Cube (B) and Their Ratio (A/B)
Author(s) -
Rossavik Ivar K.,
Deter Russell L.
Publication year - 1984
Publication title -
journal of clinical ultrasound
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.272
H-Index - 61
eISSN - 1097-0096
pISSN - 0091-2751
DOI - 10.1002/jcu.1870120903
Subject(s) - medicine , cube (algebra) , fetal head , standard deviation , abdomen , growth model , growth curve (statistics) , confidence interval , fetus , statistics , anatomy , mathematics , pregnancy , geometry , biology , mathematical economics , genetics
Abstract : Growth of the fetal head and abdomen have been monitored by measurement of the head cube (A), the abdominal cube (B) and A/B, from 12 to 41 weeks menstrual age. Growth curves for these parameters have been determined using a specially developed growth curve model [P = c(t) k+S(t) ]. R2 values of 98.0%, 96.6%, and 56.2% were obtained for A, B, and A/B, respectively. Similar results were obtained when this model was used with HC and AC data from a previous study. Variability analysis indicated a progressive increase in variability with menstrual age for both A and B while the variability of A/B decreased. The variability in the 12‐ to 17‐week interval was significantly greater for all three parameters and the A deviation distribution was asymmetric (shifted toward negative values) after 36 weeks. Variability data were used with the growth curve models to determine standard curves for A, B and A/B. Indexing Words: Fetal growth · Head cube · Abdominal cube · Growth equation.