Several Iowa clients have asked me recently "Can I stop the divorce" or "can s/he stop the divorce?" A short and brutal answer is "no," at least in Iowa. You (or your spouse) may of course employ delay tactics like asking for continuances or asking for an order requiring reconciliation like marriage counseling but unless both parties are committed to truly working on the marriage, using these tactics usually only result in more hurt and cost.
So what choices do you have? You both can choose to remain in the marriage which for some, is better than dealing with the pain, expense and disruption of divorce. You can live in a so-called "parallel marriage" which turns into a marriage of companionship and pleasantries. This probably more common than you think and especially prevalent when one spouse needs medical insurance coverage or both know they cannot maintain a reasonable lifestyle without the other's contribution.
Another option is to enter into a separation agreement which is as close to a divorce as one comes without taking the plunge.
To discuss these options and other contact a family law attorney.