Two hundreds patients (group1) with abnormal NK activity results (NKa)will receive intralipids 20% i.v. (9 mg/mL total blood volume -corresponds to 2 mL of intralipids 20% diluted in 250 mL saline; or 18 mg/mL - corresponds to 4 mL of intralipids 20% diluted in 250 mL saline) infusions and their NKa will be tested periodically. The determination of NK cell function will be performed by flow cytometry using K562 cells as targets,then follow up of the patients by the Doppler of endometrial blood follow at the time of luteal phase,and the clinical pregnancy rate.Group(2)of 180 patients will receive placebo.

intravenous intralipid 20% is given to the patients known to be have either recurrent failed IVF, RPL

Two hundreds patients (group1) with abnormal NK activity results (NKa)will receive intralipids 20% i.v. (9 mg/mL total blood volume -corresponds to 2 mL of intralipids 20% diluted in 250 mL saline; or 18 mg/mL - corresponds to 4 mL of intralipid 20% diluted in 250 mL saline) infusions and their NKa will be tested periodically. The determination of NK cell function will be performed by flow cytometry using K562 cells as targets,then follow up of the patients by the Doppler of endometrial blood follow at the time of luteal phase,and the clinical pregnancy rate.Group(2)of 200 patients will receive other routine measures.

Two hundreds patients (group1) with abnormal NK activity results (NKa) will receive intralipids 20% i.v. (9 mg/mL total blood volume -corresponds to 2 mL of intralipid 20% diluted in 250 mL saline; or 18 mg/mL - corresponds to 4 mL of intralipid 20% diluted in 250 mL saline) infusions and their NKa were tested periodically. The determination of NK cell function will be performed by flow cytometry using K562 cells as targets,then follow up of the patients by the Doppler of endometrial blood follow at the time of luteal phase,and the clinical pregnancy rate.Group(2)of 200 patients will receive routine measures.