1. Department of Epidemiology, New England Research Institutes, Watertown, Massachusetts;
2. Departments of Environmental Health and
3. Epidemiology, Harvard School of Public Health, Boston, Massachusetts;
4. Vincent Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts;
5. The Forsyth Institute, Cambridge, Massachusetts;
6. Department of Neurology, Children’s Hospital Boston, Boston, Massachusetts; and
7. Harvard Medical School, Boston, Massachusetts