Participant Time Line
Upon enrolling in the study, participants in the intervention group received the video intervention through WhatsApp, delivered to their cellphones. One month later, all of the participants were contacted telephonically by the research team to respond to the surveys. Following the unblinding of the interviewers, participants in the intervention group were asked if they had watched the videos after receiving them, and participants in the control group were asked if they had been shown any short, animated maternal health videos on the phones of others. These questions allowed us to detect any contamination in the control group and also facilitated an analysis based on the intention to treat.