Like I have mentioned in a previous answer on IVF failure in Singapore, you need to try and identify the cause of the failures.
The most difficult to rectify is the poor quality Oocyte. There are experimental techniques like transplanting the nuclear material to a healthy donor cytoplasm before fertilisation. All still very experimental, but promising techniques. They have not been approved for clinical use yet.
Empirical treatments like the use of Growth Hormone in those found to be deficient have shown variable results.