Premenstrual Syndrome

Abstract

In ovulatory women, menstruation signals both the culmination and the reinitiation of a complex, highly integrated neuroendocrine rhythm designed to effect the release of an egg and optimize the endometrial environment for early pregnancy. The follicular phase, which commences with the onset of menstruation, is characterized in the first week by low circulating levels of estradiol and in the second week by an exponential increase in estradiol concentrations as the maturation of the dominant follicle progresses. The transition between the follicular and the luteal phases is marked by an abrupt and transient fall in ovarian production of estradiol that may . . .