I agree that setting mediation would be a positive step forward. I imagine with the new baby so close, setting this up might not be feasible before the birth.
What would you like to happen in the weeks before and after the birth? More or less time with dss? No contact from biomum? I think I would write a wish list for hubby and work towards making that happen if possible, no regrets then. I am sure he feels a bit helpless in this situation and a clear plan from you might help empower you both x