[1] Univ Washington, Div Rheumatol, Seattle, WA 98195 USA
[2] Univ Calif San Diego, Dept Pediat, La Jolla, CA 92093 USA
[3] Univ Calif San Francisco, Calif Preterm Birth Initiat, San Francisco, CA 94143 USA
[4] MultiCare Good Samaritan Hosp, Gen Internal Med, Puyallup, WA USA
[5] Kaiser Permanente Washington, Dept Surg, Bellevue, WA USA
[6] Brigham & Womens Hosp, Div Rheumatol Inflammat & Immun, 75 Francis St, Boston, MA 02115 USA
[7] Harvard Med Sch, Boston, MA 02115 USA
[8] Univ Calif San Francisco, Dept Physiol Nursing, San Francisco, CA USA
[9] Univ Calif San Francisco, Inst Human Genom, San Francisco, CA 94143 USA
[10] Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA USA
[11] Coll Publ Hlth, Dept Epidemiol, Iowa City, IA USA