I actually see some other issues at play here other than the trust issue with the inlaws. If you and your husband are having problems in your marriage, that is a priority over anything having to do with the inlaws or the child. The marriage relationship must take priority over a relationship with anyone else. My advice is to communicate your concerns with your husband re his parents, and if communication with each other is not working, then a third party counselor (ie, pastor or something) would be in order.
Concentrate on your marriage. If the inlaws want the baby in the meantime, tell them you will invite them over for dinner (so the visit can be supervised), otherwise your focus right now needs to be on your immediate family. Then find a trusted babysitter so you and your husband can reignite what attracted you to each other to begin with.