Hi Shyna,
I found two clinics dealing with miscarriages on a cursory search of the internet using ryuuzan, senmon i, and yokohama as my search terms on Google (using Japanese characters). They are Yokohama Shidai (City University) and Amor Clinic. For the former, you should see Dr. Mika Okuda (probably a woman) on Thursday or the Friday doctor (Haruki), as they both seem to be miscarriage specialists. Those are the appointment dates if you are seeing them for the first time. The miscarriage specialty clinics are on Monday PM or Wednesday AM. The Amor clinic posts their success rates at treating miscarriages and their treatment protocol. To see if the doctors are any good at English, you can call and ask. You might also check out ncbi.nlm.nih.gov/sites/entrez and put in the doctor's last name and initial of first name followed by [au] in the search window to see if they have published any scientific papers in English.
The two clinic websites are:
urahp.yokohama-cu.ac.jp/p1030.html and
amor-clinic.jp/cure01.html
They are in Japanese.
Of course there are hundreds more, but these are the two that seemed like good places to start and were within the first two pages of the Google search.
The technical term for miscarriage seems to be 'fuikushou'.
Hope this is of some help.
Mari