A role for estriol in human labor, term and preterm

Although estriol has been studied as an indicator of fetal well-being in th e past, its broader biologic role has not been elucidated. Estriol in the m aternal compartment closely reflects fetal adrenal activity, and increased fetal adrenal activity prior to the onset of labor is a common link in mamm alian parturition. In humans, estriol increases before spontaneous labor an d may be a clinically useful marker for some cases of preterm labor.