Mukunda has given some guidance on this subject already, not IVF specifically, but asana within sadhana. Search this forum with the keyword [B]conception[/B].
With clients who are progressing through their pregnancy without complications, I use an earth salutation vinyasa with them, in addition to my training with Mukunda. It is grounding practice for the mind. It prepares the hips and pelvis for the birthing process and the corresponding breath (pranayam) helps to pacify vata. This must be watched closely as improper breathing (too fast, too shallow, etc.) can derange vata. A sweet and stable practice should be the goal and, of course, as always, adapt to the individual.
A sweet and stable vinyasa practice will also introduce your student to the practice of coordinating breath and movement (in the birth process, barring any complications or drug interferences, this will become a complete breath in 4 parts: pushing on exhale, resting and preparing to push on inhale, stillness with both kumbakas).
This is huge subject, but I’ll stop here. All the best in your good work.