Placental determinants of fetal growth: identification of key factors in the insulin-like growth factor and cytokine systems using artificial neural networks

Table 4 Input variables selected by the optimized (I.S.) system.

Variables	IS 1° selection	IS 2° selection
Chronological age of the mother at delivery	X	X
Sex of the newborn
Gestational age	X	X
Other siblings	X	X
Number of other siblings
Number of previous abortions
Total placental protein content in lysates
IGF-II concentration in placental lysates	X	X
IGFBP-2 concentration in placental lysates	X	X
IL-6 concentration in placental lysates
TNF-α concentration in placental lysates
IGF-I relative gene expression in placenta	X	X
IGF-II relative gene expression in placenta		X
IGFBP-1 relative gene expression in placenta
IGFBP-2 relative gene expression in placenta	X	X
IL-6 relative gene expression in placenta		X

ISSN: 1471-2431