Author contributions
A.M.E. and E.W. were primary investigators and overall responsible for the initiation, financing, design, and management of the WelTel PMTCT trial. B.N., W.M., J.M., P.O.A., K.J.C.A., E.E.G., S.R., E.W. and A.M.E. designed the study. E.K. coordinated the data collection. M.L.V. performed the data analysis, except for the subgroup and text message analyses which B.N. performed. B.N. and M.L.V. drafted the manuscript. B.N., M.L.V., W.M., J.M., A.E.K., P.O.A., K.J.C.A., E.K., R.T.L., E.E.G., S.R., E.W. and A.M.E. revised the manuscript. All authors read and approved the manuscript.