Figure 6.

Growth velocity along life. The maximum growth velocity is observed during the fetal life, reaching 75 cm/year and following an exponential curve. After birth, growth velocity follows a double exponential curve; the consequence is that the high growth velocity observed after birth progressively slows since 6–10 months of age, indicating that two dfferent kinds of factors are acting in this period. During childhood, growth velocity (lineal now) decreases to 5 cm/year, and when puberty begins, a number of factors (mainly sex steroids) acting on pituitary GH synthesis and release again increase growth velocity until 10–12 cm/year.