Can married man masturbate if doctor tells to do so

Assalamu alaikum, My wife and I have been trying for children for several years with no success. We have undertaken many tests that could not determine a biological issue with our health. We have gone through two IVF cycles unsuccessfully. Our consultant has asked that I should not refrain from ejaculation for more than 36-48 hours until the next IVF cycle is complete. However my wife will be traveling with her family for a few days during this time. I don't know how best to address this. I know the majority of opinion is that masturbation is haram, unless for medical purposes. But considering I am married and have a halal alternative (albeit not while she is travelling) I don't know where I stand with rulings. Please can you refer me to some knowledge so that I act, by Allah's will, in accordance with shariah.