Sonography has rapidly evolved and now plays a major role in the field
of reproductive endocrinology and infertility. With the increasing re
solution capacity of ultrasound devices, it has become possible to ima
ge the cyclic alterations of pelvic structures with precision. Transva
ginal sonography (TVS) has become the gold standard for ovarian follic
le monitoring, early intrauterine and ectopic pregnancy detection, and
is gaining more acceptance as a safe, noninvasive, and valid method o
f assessing endometrial maturation during the menstrual cycle. In rece
nt years, there has been a growing interest in the sonographic appeara
nce of the endometrium as a predictor of successful implantation. Howe
ver, the value of this technique in this context remains controversial
. This review discusses the clinical value and recent advances of sono
graphic evaluation of the endometrium.