Purpose: Patients with unexplained infertility may have fertilization problems. Split fertilization (ICSI and conventional IVF on sibling oocytes) is often used to avoid poor fertilization. Our aim was to assess the ability of hyaluronic acid binding (HA-binding) assay to predict spontaneous fertilization during IVF.
Methods: Prospective, blinded, controlled trial. Patients undergoing their first IVF cycle for unexplained infertility were eligible. Split fertilization was used. IVF and ICSI fertilization rates and embryo development based on 3 HA-binding cut-offs (< 60%; 60-80%; >80%) were compared.
Results: ICSI fertilization was higher than IVF, but none of the HA-binding cut-off levels predicted those cases where IVF was less effective, therefore ICSI only would have lead to improved outcome. Embryo development and morphology were similar in all cut-off groups.
Conclusions: HA-binding did not predict spontaneous fertilization in patients with unexplained infertility undergoing IVF treatment. When it was used for "screening" it did not help to select the method of fertilization.