1. Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
2. Lactation Services Department, University of North Carolina Hospitals, Main Campus, North Carolina Women's Hospital, Chapel Hill, North Carolina.
3. Division of Rheumatology, Allergy, and Immunology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
4. Division of Maternal-Fetal Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina.