Era Test

The Endometrial Receptivity Array (ERA),is a new technology which helps us to find out the exact day to transfer the embryo which results in a pregnancy.

It provide an idea as to how receptive a woman’s uterus will be at a particular stage in her menstrual cycle. Essentially, this helps to determine the best time to transfer an embryo in hopes that it will implant. The quality of embryos is the best predictor of success, but for couples who do not conceive even after many cycles of IVF, there could be endometrial factors involved. The ERA test is the first of its kind to examine endometrial receptivity as a product of gene expression of the endometrial lining at specific times during a woman’s cycle. The test looks at the cyclical pattern of 238 different genes.

An assessment of endometrial receptivity increases the chances of a successful pregnancy. For example in women with endometriosis, treatment of this condition with surgery or medical management has improved the pregnancy rates from 10% to 40% and 68%, respectively. In women with hydrosalpinges, removal or repair of the damaged fallopian tube(s) results in return of the ß3 integrin and an improvement in pregnancy rates. Women who were missing the endometrial ß3 integrin achieved pregnancy with more than a 65% success rate when treated for ninety days with the GnRH analog, Lupron Depot. In contrast, treatment of laser ablation only achieved a 40% success rate and the time to pregnancy was greatly delayed.

Genetic Factors Affecting Endometrial Receptivity

Many genetic factors are likely to be involved in the success or failure of implantation. The endometrial signature of genes during the window of implantation provides the opportunity to design diagnostic screening tests for patients with infertility and endometrial disorders and for targeted drug discovery for treating implantation-based infertility.

• Female mice with Hoxa 10 removed exhibit uterine factor infertility, with normal ovulation and embryo formation but complete implantation failure. Hoxa 10 expression in the endometrium rises at the time of ovulation and has been shown to be essential for human implantation. The impact of Hoxagene expression in the endometrium of women receiving conception has yet to be evaluated.
• Simmonds and Kennedy reported a novel gene, uterine sensitization-associated gene-1 (USAG-1), which is preferentially expressed in the maximal duration of endometrial receptivity.
• Another new gene has been designated as endometrial bleeding associated factor (EBAF) found to be expressed in the late secretory and menstrual phase of the endometrium. Some insights are proposed for the role-played by this new gene in the endometrial preparation of implantation.