DuoFertility

Implantation? is the adherence of the embryo? to the womb? lining. It takes place in the first 10 days after ovulation. At this stage, the embryo will have already undergone several cellular divisions, and will be referred to as a blastocyst?. During the second phase of the menstural cycle, the presence of progesterone in the bloodstream induces changes in the endometrium? that will allow implantation to occur.

Implantation refers to the attachment of the embryo to the womb lining Implantation allows the baby to develop and receive nutrients and oxygen. Some women are able to detect changes in their temperature around the time of implantation, which can be used as an early indication of pregnancy. Implantation always occurs during the "implantation window" which is the optimal time for the embryo to adhere to the womb. If implantation does not take place during this window, pregnancy will not occur. The length of the luteal phase? is thought to be important for successful implantation, and 5% of women have repetitive implantation failure because their luteal phase is too short. However, further scientific studies need to be conducted to discover more about how this is related to infertility.

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Endometrial receptivity markers, the journey to successful embryo implantation. Click here to read Links

Hum Reprod Update. 2006 Nov-Dec;12(6):731-46. Epub 2006 Sep 18. Links Achache H, Revel A. Department of Obstetrics and Gynecology, Hadassah University Hospital, Jerusalem, Israel. Human embryo implantation is a three-stage process (apposition, adhesion and invasion) involving synchronized crosstalk between a receptive endometrium and a functional blastocyst. This ovarian steroid-dependent phenomenon can only take place during the window of implantation, a self-limited period of endometrial receptivity spanning between days 20 and 24 of the menstrual cycle?. Implantation involves a complex sequence of signalling events, consisting in the acquisition of adhesion ligands together with the loss of inhibitory components, which are crucial to the establishment of pregnancy. Histological evaluation, now considered to add little clinically significant information, should be replaced by functional assessment of endometrial receptivity. A large number of molecular mediators have been identified to date, including adhesion molecules, cytokines, growth factors, lipids and others. Thus, endometrial biopsy samples can be used to identify molecules associated with uterine receptivity to obtain a better insight into human implantation. In addition, development of functional in vitro systems to study embryo-uterine interactions will lead to better definition of the interactions existing between the molecules involved in this process. The purpose of this review was not only to describe the different players of the implantation process but also to try to portray the relationship between these factors and their timing in the process of uterine receptivity. PMID: 16982667 [PubMed - indexed for MEDLINE] [/collapse] [collapse collapsed]

 

The prevalence and epidemiology of luteal-phase deficiency in normal and infertile women. Click here to read Links

Clin Obstet Gynecol. 1991 Mar;34(1):157-66.Links The prevalence and epidemiology of luteal-phase deficiency in normal and infertile women. Olive DL. University of Texas Health Science Center, San Antonio. The difficulty in determining the prevalence and epidemiology of LPI lies in the ambiguity of diagnosis. To define the abnormal, a complete delineation of normal is first required; this has been disregarded for most diagnostic criteria of this disorder. Once normal is defined, a link between the abnormal state and subfertility is required to demonstrate clinical relevance; this has yet to be shown with any form of LPI criteria. Despite this, some pieces of the puzzle are apparent. In the form of a short luteal phase LPI is present in roughly 5% of ovulatory cycles. The rate also tends to increase at the extremes of reproductive age. The rate of hormonal- or biopsy-diagnosed LPI appears to be in approximately the same range, although the criteria for diagnosis are much more poorly defined, and the rate of "abnormal" is often built into the definition. Finally, ongoing development of more precise and accurate tools for diagnosis promises to produce more and better data in the future to furnish the clinician with greater insight into the rate and overall importance of LPI as a cause of infertility. PMID: 2025966 [PubMed - indexed for MEDLINE] [/collapse]