does injuring the endometrium ( with D&C or endometrial biopsy) improve ivf rates?

this is a topic that has been hotly debated over the years. The rationale behind performing a biopsy or a quick scraping of the uterus prior to IVF is that the healing that follows the scraping improves the immune profile.
2 aprroaches hve been takent to achieve this : the first is to do an endometrial biopsy on day 21 the cycle preceding the  IVF cycle , the second approach is to do a biopsy  on the day of egg retrieval. A total of 5 well designed studies was analyzed by the physicians from  Cochran database. the Cochrane Database is a non for profit. " Cochrane Reviews are unique because they are both produced by, and are relevant to, everyone interested in the effects of human health care. Based on the best available evidence.........Practitioners can find out if an intervention is effective in a specific clinical context."

The result of the review is that if the "scraping" was performed at time of retrieval , this resulted in decreased pregnancy rates . If the procedure was performed the preceding cycle resulted in  increased pregnancy and increased live birth rates.

Endometrial Injury in the luteal phase of the cycle preceding IVF  seems to improve IVF outcome , this procedure can be offered to increase chances for pregnancy when previous IVF attempts have failed.

You can locate the study here

Is progesterone elevation on the day of human chorionic gonadotrophin administration associated with the probability of pregnancy in in vitro fertilization?

This  is an important question. IVF cycles are  monitored with serial measurements of estrogen ,  LH ,and Progesterone. At times , towards the last day of stimulation  we observe a slight rise of progesterone. some have questioned whether this progesterone level increase ( slight increase  not majour ovulation increases of 2 or 3) reduces the chance of pregnancy.

The short answer to this question is "the best available evidence does not support an association between progesterone elevation on the day of hCG administration and the probability of clinical pregnancy in women undergoing ovarian stimulation with GnRH analogues and gonadotrophins for IVF".

This is based on a large meta analysis that you can find here