Foley Balloon for Cervical Preparation Before Dilation and Evacuation

To evaluate the Foley Balloon technique for cervical preparation before second trimester surgical abortion between 16 and 21 weeks estimated gestational age in combination with misoprostol to prepare the cervix before dilation and evacuation (D\&E) instead of osmotic dilators (Laminaria). Specific Aim One: Assess definitively whether using a Foley Balloon and Misoprostol is non-inferior to osmotic dilators for cervical preparation before D\&E. Specific Aim Two: Evaluate patient satisfaction with the two methods of second trimester abortion. Specific Aim Three: Evaluate provider satisfaction with the two methods of second trimester abortion.