BackgroundThis study evaluated an online childbirth education course on childbirth self-efficacy and, subsequent birth related posttraumatic stress disorder (PTSD) symptoms and mother-infant relationship quality.MethodThree group (intervention, passive control, active control) parallel randomised controlled trial. Groups were assigned using computer generated random allocation. For the passive control group participants were instructed to carry on with whatever they were currently undertaking with their pregnancy, while the active control group were asked to read a booklet comprised of twelve birth stories. The purpose of the active control was to check if the act of having an activity to complete would influence outcomes. For the online course group (intervention) participants were asked to complete the online version of a birthing course designed by She Births®. One hundred and twenty-five women residing in Australia between 12 and 24 weeks pregnant were recruited online. Participants were asked to complete their required activity between 24 and 36 weeks pregnant. Childbirth self-efficacy scores were tested pre and post intervention (time one and time 2), PTSD symptoms and mother-infant relationship quality were tested at six weeks and six months postnatal.ResultsThere was no significant interaction by group for childbirth self-efficacy scores. Mean difference scores at time one (pre-intervention) and time two (post-intervention) for each group indicated a trend in the online group towards higher childbirth self-efficacy compared with the two control groups. The main effect of group on birth related PTSD scores was not statically significant at six weeks postnatal or at six months postnatal. The main effect of group on mother-infant relationship scores was not statically significant at six weeks postnatal or six months postnatal.ConclusionsTrends showed childbirth self-efficacy scores to be higher in the intervention group compared with the two control groups, demonstrating effectiveness for the intervention. Paradoxically, PTSD scores were higher in the intervention group compared with the two control groups and therefore also reported poorer mother-infant relationship quality. External factors may be more important than childbirth self-efficacy highlighting the need for a holistic approach that addresses systemic and socio-political influences to improve communication, autonomy, and respectful maternity care.Trial RegistrationThis trial was retrospectively registered with the Australian New Zealand Clinical Trials Registry number: ACTRN12624000241538 on March 11, 2024.