The complexity of fetal brain development cannot be overstated. Even when one considers its unencumbered development, a myriad of untoward events could occur by chance alone. It is understandable then that any deviation from the normal intrauterine environment could influence the delicate balance between growth and differentiation of neural tissue and hence the rate of functional maturation of the developing fetal brain. When performing tests of neuromuscular maturation, we are making an indirect assessment of brain maturity, which in turn gives us an indirect measure of gestational age.