Steroid such as prednisolone or medrol is typically prescribed in an IVF cycle for four days prior to transfer to prevent your body from rejecting the embryo(s).
In some cases where a woman has recurrent pregnancy losses due to elevated natural killer cells and in some women with genetic disorder that causes inflammation in her body (such as familial mediterranean fever), steroids such as medrol and dexamethasone have been prescribed in some cases beginning as early as day 1 of the woman’s cycle for transfer to reduce inflammation and immune system (natural killer cells). In some cases, steroids are not enough to suppress a woman’s natural killer cells, and the doctor may prescribe IVIG or intralipid in addition to steroids to further suppress her immune system.
I am one of those women who have used dexamethasone as early as day 1 of my cycle continuing til the end of my trimester if pregnancy continues but my pregnancy was suspected to be either ectopic or blighted ovum so next cycle my doctor is going to add intralipid to suppress my immune system further and also I have familial mediterranean fever so i need steroid to reduce inflammation in my system.
You are in good hands on the steroid. I even had to ask my doctor to keep me on steroid longer and my pregnancy went the furthest the cycle with longer steroid, unfortunately it was a nonviable pregnancy so we had to end it.
You don’t have to be in an IVF cycle to take steroids. If you have been able to get pregnant naturally and have recurrent miscarriages or did IVF or IUI with BFN, immune system (such as natural killer cells) is one thing you can get tested for. And you can have the doctor prescribe it for you if you tested positive for it. But not all fertility doctors believe in immune system causing miscarriages or implantation problem especially if it is known that you have excellent embryo quality so you need a reproductive immunologist to do the tests for you.