The purpose of this study is to determine whether in Assisted Reproductive Technologies the treatment with GM-CSF, a growth factor working on stem cells, may improve the pregnancy rate and pregnancy outcome in patients experiencing recurrent implantation failure in IVF cycles.

The GM-CSF is a cytokine promoting leukocyte growth, but also trophoblast development. In this randomized sudy investigators will test this cytokine as a treatment for recurrent implantation failure after IVF, at leat three failed previous IVF attempts.

The study will be conducted in 100 women with recurrent implantation failure of egg donation cycles. The inclusion criteria will be, at least three previous failed Egg Donation attempts where at least 4 good blastocysts were transferred, women less than 50 years old, absence of systemic diseases. These women will undergo egg donation cycle and they will randomly divided in two groups: one (50 women) will be treated with subcutaneous GM-CSF 60 micrograms/day from the day of transfer to the day of β-hCG test, and if it will be positive the treatment will be continued for other 40 days; the group of control will be treated with subcutaneous saline solution infusion in the same way of the study group. Primary outcomes will be considered: pregnancy rate and live birth rate, the of β-hCG levels at 14/21/28 and 35 days after embryo transfer.

Inclusion Criteria:

• women 50 years old or less with three or more previous egg donation cycles failed,
• with a total of at least 4 blastocysts replaced in uterus

Exclusion Criteria:

• chromosomal defects in the patients,
• metabolic diseases (diabetes etc.)
• genetic diseases (thalassemia, cystic fibrosis, etc.)