It is not known but test is extremely high enough to convince the mother to make decision with abortion due to financial reason related to medical care.
I don't think HoH/Deaf will be detectable by test right now, but in case, the doctor may have to inform about treatment, rehabilitation, planning with deaf babies. It will be sad if they are healthy deaf baby and could become very smart student in the future.
You can ask legislators to restrict the abortion to certain medical condition, such as mental disorders, fatal diseases only, so it will prevent mothers from abort healthy deaf baby.