### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
I have been under 2 IVF (6 embryo transfer) cycles that were all not successful - I have visit a new IVF center and again 2IVF (2 embryo transfer) cycles that were all not successful. After that doctor has sugeested for Era report before going for next ivf. That Report is normal as per doctor it is p+5. I have visited doctor at second day of my period and he has done a scan on my whom and ovaries. And suggested to visit again at 12th day of my period for checkup and he said that tranfer will be on 15th-16th day of period. i would like to know that in this case what is meaning of ERA because earlier in 2 cycle they have transfered on 15th or 16th day so what is meaning of ERA. And i want to know that what should be the uterus size before transfer and miprogen or progaynova is useful to increase size of uterus please answer as soon as possible

### output:

Hello there, Thanks for writing in. I learned from your writing that you have so far undergone 4 IVF cycles which were unsuccessful. Let me help you understand in this scenario the meaning of implantation failure.  When pregnancy test comes negative in two or more IVF cycles where 6 or more reasonably good quality embryos are transferred then it is assumed to be implantation failure which means the embryo has failed to get buried in the soil(which is endometrium). When the embryo is transferred, the endometrium needs to receive it with the help of finger like microscopic structures to help it get buried. And the endometrium can do it only within a very short time frame, usually 6 to 7 days post ovulation. Sometimes this timeframe within which it can receive seems to be shifted either early in the cycle or later. By doing an ERA(Endometrium receptivity array) test we are able to predict this timeframe much precisely so that the embryo transfer can be timed accordingly.  2. The size of the uterus doesn't matter for pregnancy unless its tiny. 3. Progynova is not being used for increasing the size of uterus. Hope your question is satisfactorily answered. Good luck.