Experts in fetal development provide markedly different assessments of the kind and degree of pain (if any) experienced by the fetus ("see Fetal pain"). Although in the second and third trimesters the nervous system is largely in place, the level of consciousness or awareness of the fetus is a matter of debate. Experiments aimed at measuring fetal pain have yielded results that are somewhat open to interpretation, given that measurable reactions of the fetus to stimuli may not correspond directly to an adult experience of pain.