Interventions: Subjects receive transvaginally, utilizing an insemination catheter, 2 slow intrauterine lavages with CSF-1 (Neupogen or generic, 300ug in 1 ml) 5 and 3 days, respectively, before embryo transfer and controls receive 1 ml of saline instead. Patients who do not become pregnant will after one month washout times continue treatment in the opposite study arm if they so choose and if they have remaining embryos.