I would advise your husband to IMMEDIATELY file for divorce in Washington the minute you left for Wisconsin, with or without the baby being in utero. The court will then order the child back to Washington. Whether you want to come with will be up to you, however, the child will be back where dad can have contact.
And until you establish residency in Wisconsin, Washington will have jursidiction, so you won't be able to legally file for divorce in Wisconsin for quite a while. You have to understand that the only family that matters here is the family of the baby. That being mom and dad. The family twice removed is irrelevant.

