TWO AUTHORS REPLY.
Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
Neil J
NJ
Perkins
Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD schistee@mail.nih.gov.
Enrique F
EF
Schisterman