1. Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA
2. Biomedical Research and Informatics Core, Michigan State University, East Lansing, MI, USA
3. Department of Physiology, Michigan State University, East Lansing, MI, USA
4. Department of Gynecology and Obstetrics, Lillebaelt Hospital, Kolding, Denmark
5. Department of Clinical Biochemistry and Immunology, Statens Serum Institut, Copenhagen, Denmark
6. Department of Statistics and Probability, Michigan State University, East Lansing, MI, USA