A randomized clinical trial to evaluate the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) in embryo culture medium for in vitro fertilization.

Objective: To evaluate the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) in embryo culture medium on ongoing implantation rate (OIR).

Design: Multicenter, randomized, placebo-controlled, double-blinded prospective design.

Setting: Fourteen Scandinavian fertility clinics.