1. Department of Obstetrics & Gynecology, Division of Maternal-Fetal Medicine, University of Wisconsin School of Medicine and Public Health-Madison, Madison, Wisconsin;
2. Comparative Pathology Laboratory, Research Animal Resource Center, University of Wisconsin-Madison, Madison, Wisconsin; and
3. Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Wisconsin School of Medicine and Public Health-Madison, Madison, Wisconsin