Endometrial dating chart
Morphologically, the endometrium is one of the most dynamic target tissues in women. Its cyclic structural changes mirror changes in metabolic functions, and both are regulated by ovarian estradiol and progesterone. Because of this interplay of structure, function, and ovarian hormonal stimuli, the endometrium is considered one of the most sensitive indicators of the hypothalamic-pituitary-ovarian hormonal axis. As a result, morphologic evaluation of the endometrium is used in diagnostic evaluation of infertile patients to determine whether ovulation is occurring Fig.
Schematic representation of steroid hormone-morphologic interactions during the endometrial cycle. Estradiol promotes endometrial proliferation, whereas after ovulation, progesterone converts estradiol-primed endometrium into secretory tissue. Postovulatory estradiol amplifies the progesterone effect, and after withdrawal of both estradiol and progesterone, the endometrial mucosa breaks down and regenerates within the period of menstruation.
Steroid hormone control of endometrial, epithelial, stromal, and presumably endothelial cells is mediated by estrogen receptors and progesterone receptors. These steroid receptors are specific proteins concentrated exclusively in the nuclei of both endometrial epithelial and stromal cells, as well as the endothelial cells of stromal capillaries. They have high affinity to bind estradiol and progesterone, respectively.
This chapter contains a review of the technical procedures for handling endometrial tissues and a discussion of the morphologic aspects of the endometrium, focusing on the interpretation and understanding of the physiomorphology of the endometrial cycle. In current practice, the device that is most often used is the Pipelle endometrial aspirator.
To ensure a maximum amount of tissue for morphological reading, the specimen should be placed on a piece of lens paper or some other adhesive tissue and then immersed in the fixative. By this means, all of the tissue fragments remain tightly attached to the lens paper, rather than floating in the fixative, and no tissue will be lost for histologic examination.
In premenopausal women with regular menstrual cycles, histological preparations include the upper portion of the functional layer of the endometrium. This is necessary, for in most instances morphological changes occur in the functionalis as opposed to the basalis layer, and, by inference, provide a clinically useful diagnosis. In cases in which little or no tissue is obtained but the endometrium was penetrated with the aspirator, a repeat procedure should be performed.
If the repeat aspiration still yields little tissue, one can assume severe endometrial atrophy or obstructing endometrial polyp. Taking an endovaginal ultrasonography of the uterus may solve this dilemma. If the aspirator is 'blocked' at the lower uterine segment internal os , traction may be applied on the uterus with either a single-toothed tenaculum or preferably an Emmet tenaculum placed about half a centimetre into the anterior endocervical canal. This will help pass over the area of resistance.
The pathology requisition should contain all pertinent information, including date of last menstrual period. The best way to prove or disprove that ovulation has taken place is to take an endometrial sample on cycle day 22 or later, preferably at the onset of uterine bleeding. By obtaining samples at the time of early uterine bleeding, the pathologist will be able to determine whether the bleeding is caused by the breakdown of postovulatory, secretory endometrium; by focal necrosis of the endometrium associated with anovulation; by other pathologic states; or by hormone administration.
Also, during the period of bleeding, both the external os and the isthmus lower uterine segment are widened, facilitating penetration of the biopsy forceps into the endometrial cavity. The final argument in favor of taking samples at the onset of bleeding is that endometrium of the first 2 days of menstruation is relatively easy to recognize histologically. In contrast, secretory-phase endometrium often demonstrates subtle changes and, in many cases, combinations of morphologic changes, resulting in most instances in errors of 4—5 days.
The pathologist can improve this to 2—3 days, however, by acquiring expertise in endometrial dating all cases of normal endometria are to be dated regardless of reasons for sampling , and by basing the dating on those endometrial morphologic alterations that represent the most advanced phase of the menstrual cycle. In any case, one should not average cycle days and report 'POD 3 or 17 th -day secretory endometrium'.
Endometrial biopsies are not to be taken at the onset of bleeding in the following two conditions: These changes are presumably due to the poor development of the corpus luteum. According to most investigators, measurements of serum progesterone levels rather than histological dating of the endometrium provide for the best assessment of LPD see discussion later in this chapter. In LPD, circulating progesterone levels are decreased and not sufficient to promote full secretory differentiation of the endometrium.
A repeat biopsy taken during the same period of the following cycle will further confirm an abnormally short corpus luteum life span. In cases of clinical membranous dysmenorrhea, the endometrial biopsy should be taken on cycle days 5— In these instances, the histologic specimens contain large fragments casts of endometrium, often with focal Arias-Stella reaction, or star-shaped glands with dense stroma alternating with foci of normal menstrual endometrium.
Such a condition, also called irregular shedding, is presumably associated with a persistent corpus luteum from a recent or remote intrauterine or ectopic pregnancy and with relatively increased blood progesterone levels. Because of the stabilizing effect of progesterone on lysosomal enzymes and prostaglandins, menstrual breakdown may be delayed, prolonged, and extensive.
The major morphologic criteria useful for dating the endometrium throughout the cycle are presented in Fig. In routine dating, the pathologist should avoid bias by evaluating the histologic section before reading the clinical information. After examining the specimen, the pathologist should attempt to correlate histology with clinical history. In the most common terminology for dating the endometrial biopsy, day 1 is used as the first day of bleeding, and this is used in Fig.
It is not necessary to date the endometrium during the proliferative phase. During this period, daily morphologic alterations are not sufficiently distinctive to provide adequate benchmarks for accurate dating. Also, because proliferation precedes the ovulatory period, dating proliferative endometrium gives the clinician no relevant information on whether ovulation is occurring. The daily changes in the endometrium during the postovulatory period were, in the past, considered significant enough from one day to another to provide accurate evaluation of the endometrial cycle.
Major morphologic criteria for dating the endometrium during the menstrual cycle. The reliability of endometrial histological dating as a diagnostic tool in cases of infertility has recently been challenged for lacking precision and inter- and intra-observer agreement variability. This suggests that distinctiveness exists in the responsiveness of the glands and stroma presumably because they have different biological functions to circulating sex steroids.
This is understandable, for the menstrual cycle is a dymanic succession of biological phenomena with inherent variability. Finally, one has to realize that the day of ovulation is also subject to variation, for a given patient may ovulate on day 13, 14 or 15 or even later of a given menstrual cycle. To circumvent the limitations of the Noyes et al histology criteria, 4 it is recommended to use three- rather than two-day endometrial stromal delay development in assessing LPD.
It has been suggested, furthermore, to use two parameters, e. During this period, the endometrial lining undergoes rapid degeneration and regeneration. Both phenomena are presumably independent of hormonal influence, as estradiol and progesterone levels are low. The stroma beneath the surface epithelium contains blood lakes, fragmented stromal cells, and inflammatory exudate.
These rapidly become generalized, resulting in a rough, friable, hemorrhagic surface. When seen in cross-section, the functional layer of the endometrium occupies the upper two thirds of the entire thickness; the lower third or basal layer changes very little during the endometrial cycle. On cycle day 2, the functional layer becomes disorganized, containing predecidual stromal cells admixed with epithelial glandular cells; both cellular systems undergo extensive apoptotic cell death initiated by a rapid decline in circulating estrogen and progesterone in the preceding days.
The isthmic endometrium is not significantly sensitive to cyclic hormonal stimuli and is not used for dating purposes. The menstrual fluid is made up of autolyzed tissue admixed with a heavy polymorphonuclear exudate, red blood cells, and proteolytic enzymes. One of the latter is blood protease plasmin, which prevents clotting of menstrual blood.
Plasminogen activators, which convert plasminogen into plasmin, are found in and released from degenerated endometrial vascular endothelium. During cycle days 1 and 2, synthesis of nuclear deoxyribonucleic acid DNA is near zero level in the secretory functional layer of the endometrium. These findings indicate that the cellular components of the functional layer undergo irreversible cell injury before being expelled during the menstrual period. On cycle days 2 and 3, the functional layer gradually becomes cleaved off from the underlying basal layer, resulting in a thin, denuded basal layer with a ragged surface onto which residual basal gland stumps open.
Starting on day 2 and for the subsequent 2 days, proliferation of the basal gland epithelium begins in the areas of denudation. The surface of the endometrium is re-epithelialized as the residual glandular epithelium spreads over the denuded surface. Another source of resurfacing epithelium is the surface epithelium of peripheral regions of the endometrial cavity, such as the lower uterine segment and peritubal ostia, which remain intact during the menstrual period. The subsequent development of interanastomoses between converging epithelial proliferations leads ultimately to complete reconstruction of a new surface epithelium by cycle day 5.
Complete re-epithelialization of the surface coincides with cessation of bleeding. DNA tracing studies have shown that increased DNA synthesis is confined to the basal layer of the body and fundus of the uterus and the adjacent isthmic and peritubal-ostial endometrial mucosa, all of which remain intact during menstruation. This increase occurs only after complete denudation of the basal layer by cycle day 3.
The postmenstrual endometrium is repaired by cellular migration and replication of surface epithelial cells. These features are consistent with ameboid contraction-expansion-mediated motility. Typically, the regenerative surface epithelium is devoid of cells involved in DNA synthesis or mitoses Fig. Regenerative endometrium.
Surface epithelial cells supported by tightly packed stromal cells. Both lack DNA synthesis as evidenced by negative immunostaining reaction for Ki x Endometrial stromal cells modulate the growth, steroid hormone action, and functional differentiation of the epithelial cells. The basement membrane provides anchorage and participates in the control of proliferation and migration of epithelial cells as well as in their differentiations.
An essential component of epithelial regeneration is provided by stromal cells which aggregate in cellular 'balls' beneath the regenerative surface epithelium Fig. Menstrual endometrium, cycle days 3 and 4. Note dense stromal cell aggregates beneath the regenerative surface epithelium arrow x Tenascin, an extracellular matrix protein, is immunolocalized around proliferative endometrial glands and is believed to enhance epithelial cell migration and proliferation during periods of postmenstrual repair by inhibiting cell attachments to fibronectin.
After the initial epithelial spread, cell division and migration operate simultaneously until a confluent surface layer has been regenerated by cycle day 5. The sudden increase in nucleic acid synthesis and a very short DNA-synthesis phase of the regenerative cells result in accelerated tissue turnover. These characteristics of migration and accelerated tissue turnover explain the spectacularly rapid wound healing capability of the human endometrium.
DNA and ultrastructural data do not support the concept that the regenerative endometrium derives directly from persistent secretory spongiosa or stromal fibroblasts of the endometrium. Indeed, during cycle days 3 and 4, despite increased DNA activity, plasma levels of estrogens and progesterone receptors are low and unchanged from the premenstrual values. By immunostaining, the regenerative surface epithelium and underlying stromal cells are seen to be depleted of receptors for estradiol and progesterone Fig.
Regenerative post-menstrual endometrium. Immunostaining for ER is negative in regenerative surface epithelium arrow and the immediately underlying stromal cells. In contrast, the endometrial glands and stromal cells in the deeper layer immunostained strongly for ER and PR not shown. The findings suggest that the early phase of regeneration is independent of hormonal influence x Experimental endometrial regeneration in the rabbit has shown that proliferation kinetics and morphologic alterations of the regenerative but estrogen-deprived atrophic endometrium associated with ovariectomy are similar to those in animals with intact ovaries.
These changes are accompanied by an increase in plasma levels of estrogens and progesterone receptors and a slight decrease in serum pituitary hormones, alterations that are consistent with target cell sensitivity and response to preovulatory estradiol. The preovulatory endometrium demonstrates proliferative changes in the glands, stromal cells, and vascular system Fig.
accuracy, and evaluate the usefulness of dating the endometrial biopsy. the use of his endometrial dating chart prepared in from the criteria used in the . We are indebted to Dr. C. H. Duncan for the use of his private cases; to Dr. P. F. Latour for the use of his endometrial dating chart prepared in from the.
Skip to search form Skip to main content. Endometrial dating and determination of the window of implantation in healthy fertile women. Acosta and Laura Elberger and M. Cirri Borghi and Juan C. Daily vaginal ultrasounds.
Our plans for , click here for details. Uterus Non tumor Dating of endometrium Author: Nat Pernick, M. Page views in Cite this page: Pernick N.
Morphologically, the endometrium is one of the most dynamic target tissues in women. Its cyclic structural changes mirror changes in metabolic functions, and both are regulated by ovarian estradiol and progesterone. Because of this interplay of structure, function, and ovarian hormonal stimuli, the endometrium is considered one of the most sensitive indicators of the hypothalamic-pituitary-ovarian hormonal axis. As a result, morphologic evaluation of the endometrium is used in diagnostic evaluation of infertile patients to determine whether ovulation is occurring Fig. Schematic representation of steroid hormone-morphologic interactions during the endometrial cycle. Estradiol promotes endometrial proliferation, whereas after ovulation, progesterone converts estradiol-primed endometrium into secretory tissue. Postovulatory estradiol amplifies the progesterone effect, and after withdrawal of both estradiol and progesterone, the endometrial mucosa breaks down and regenerates within the period of menstruation. Steroid hormone control of endometrial, epithelial, stromal, and presumably endothelial cells is mediated by estrogen receptors and progesterone receptors.