1. Department of Obstetrics and Gynecology; The University of Kansas School of Medicine-Wichita; Wichita Kansas
2. Department of Anesthesiology; University of Kansas School of Medicine-Wichita; Wichita Kansas
3. Department of Environmental and Occupational Health; School of Public Health; University of Medicine and Dentistry of New Jersey; Piscataway New Jersey USA
4. Department of Environmental and Occupational Medicine; Robert Wood Johnson Medical School; University of Medicine and Dentistry of New Jersey; Piscataway New Jersey USA