Iândora Krolow Timm Sclowitz, Iná S Santos*, Marlos Rodrigues Domingues, Alicia Matijasevich and Aluísio J D Barros
* Corresponding author: Iná S Santos inasantos@uol.com.br
BMC Pregnancy and Childbirth 2013, 13:20 doi:10.1186/1471-2393-13-20