ABSTRACT
Introduction 253 Endometrial vascular development 253 Modification of menstrual loss by drugs 256
Assessment of heavy menstrual loss 258 Conclusion 260 References 260
The endometrium consists of a basal layer and a superficial functional layer. In the absence of pregnancy, the corpus luteum undergoes regression with subsequent decline of progesterone. This results in shedding of the superficial layer of the endometrium known as menstruation. Repair and remodeling of the endometrium then begins in preparation for implantation of an embryo in a new cycle. Although the hormonal prerequisites for menstruation have been established, namely withdrawal of progesterone from an estrogenprogesterone primed endometrium, the factors responsible for inducing the vascular changes associated with menstruation have yet to be fully elucidated. Disorders of menstruation are of increasing importance in gynecology, since women in developed countries now experience 10-fold the number of menstrual periods (400 vs. 40) in their lifetime than their ancestors did 100 years ago.1 This is likely to be due to an earlier menarche, fewer pregnancies, and reduced lactation.
