Luteal phase insufficiency: clinical aspects.

The author analyzes different controversial clinical aspects of luteal phase insufficiency (LPI) on the basis of his own data. Conceptual and diagnostic concerns include: (1) the lack of predictive value of midluteal plasma progesterone determination regarding the progestational transformation of the endometrium, and (2) the need for a minimum of two, and even three, endometrial biopsies for diagnosis of LPI. From an etiologic point of view, follicular phase determinants of LPI are emphasized. Primary therapeutic approaches of LPI and the effectiveness and significance of such therapy on fertility are discussed.