What is known and what is new about this study?  • Application of 7.1% chlorhexidine digluconate for umbilical cord care (CHX) is recommended by the World Health Organization for home births in high newborn mortality settings, and is being scaled up in many countries, including for hospital births.  • There are limited data tracking coverage at national or global levels. Although the Demographic and Health Surveys’ (DHS) additional modules have optional questions, there is little country uptake and these are not yet validated.  • EN-BIRTH is the first multi-country observational study to assess validity of the use of CHX measurement (n = 12,379 observed newborns) compared to women’s report on exit survey and routine register-recording. Survey – what did we find and what does it mean?  • We used the same survey questions as the DHS optional newborn module.  • We found high observed coverage (96.6%) but also high (71.5%) “don’t know” replies from women reporting on application of CHX to their newborn’s umbilical cord.  • Survey-reported coverage (11.3%) vastly underestimated observed coverage (96.6%) in hospitals and was extremely inaccurate. Register – what did we find and what does it mean?  • Registers designed with a specific column more accurately recorded the high coverage of CHX application than those with non-specific columns.  • The same register design performed differently in two separate facilities, and CHX coverage was slightly overestimated (9.0%) in one.  • Qualitative data highlighted opportunities to improve register design, completion and use, especially training and supervision. Gap analysis for quality of care and measurement  • Almost all newborns observed received CHX, hence the coverage gap was small, except after caesarean birth in one facility.  • Quality of care in terms of timing revealed that most newborns (92.2%) received CHX within 1 h of birth.  • Further research is needed to assess the optimal sequencing of immediate newborn care interventions to avoid separation of women and newborns, promote early breastfeeding, and ensure that CHX application enhances and does not delay time sensitive practices. What next and research gaps?  • CHX has become a part of immediate newborn care policy in many countries, including for facility births.  • For institutional births, well-designed routine registers have higher accuracy than women’s exit survey-reports, but research is required on design and data flow in health management systems.  • Given the poor performance of survey-reported data for facility-based CHX use, further survey validation research should focus on home births, or postnatal application by women to explore how best to measure coverage outside facility-based systems.