Barbara Luke, Sc.D., M.P.H., R.N., R.D., is a professor in the Department of Obstetrics, Gynecology, and Reproductive Biology at Michigan State University. She has published numerous research studies on multiple pregnancy through the University Consortium on Multiple Births, with colleagues from universities around the country. She is also the author of Every Pregnant Woman's Guide to Preventing Premature Birth and coauthor, with Tamara Eberlein, of Program Your Baby's Health. Tamara Eberlein, an award-winning health journalist, has published hundreds of articles on health, parenting, and psychology. She is the author of four books, including Sleep: How to Teach Your Child to Sleep Like a Baby. She is also the mother of twins.