K.L.
I don't know how common it is, but my cousin had this happen to her 4 different times, and none of the children were down syndrome babies. Her husband is also Asian, although I am not sure exactly where his family is from. I am not doctor and this could just be a coincidence, but it is my experience with it. I am sending good wishes. Congratulations on what will be a beautiful grandbaby in any situation!
Updated
I don't know how common it is, but my cousin had this happen to her 4 different times, and none of the children were down syndrome babies. Her husband is also Asian, although I am not sure exactly where his family is from. I am not doctor and this could just be a coincidence, but it is my experience with it. I am sending good wishes. Congratulations on what will be a beautiful grandbaby in any situation!