I'm sorry to tell you that this is a very serious condition. According to one website:
The vast majority of multicystic kidneys occur on one side (left side). Occasionally it may occur on both sides but this is incompatible with life, primarily because the kidney is responsible for producing the amniotic fluid which is vital to lung development.
Another website says:
By lack of amniotic fluid lung development is compromised and is incomplete.
It was very hard to understand some of the tecnical language that was used. I think you should discuss this with your ob/gyn.