The iRRRd study is an ongoing prospective longitudinal prenatal birth cohort study based in Cox's Bazar, Bangladesh. Between February 2023 and March 2024, 2,888 pregnant women were enrolled (approximately 80% Rohingya refugees living in camps, 20% Bangladeshi host community). The study aims to investigate (1) the effects of being conceived, gestated, born, and raised in contexts of conflict and forced displacement on child health and development; (2) the mechanisms underlying the intergenerational transmission of conflict and displacement trauma to offspring; and (3) the sources of heterogeneity in these associations across individual, social, biological, and contextual risk and protective factors. Five waves of data collection have been completed: prenatal recruitment (Wave 1), third-trimester follow-up for a subset of the sample (Wave 2), birth (Wave 3), 28 days postpartum (Wave 4), and 6 months postpartum (Wave 5, completed April 2025; N=2,526). This registration covers Wave 6, the 36-month follow-up, in which target children are assessed when they reach 36 months of age. Anticipated enrollment for this wave is approximately 2,200 mother-child dyads. Waves 1-5 were conducted without preregistration due to logistical and timing constraints inherent to launching large-scale research in a complex humanitarian context. Design and preparation for the 36-month wave began in June-July 2025, and field piloting of study procedures and measures began in September 2025. Follow-ups with children reaching 36 months of age began in late May 2026. The original planning estimate of March 2026 reflected the 36-month mark for the earliest-born children in the cohort (first births occurred in March 2023); the ±2-month eligibility window (Part 5) accommodated the modest delay to actual fieldwork start. Up to the first week of August, fieldwork progressed slowly with a smaller number of enumerators, as several measures were still being refined and modified based on ongoing piloting. We consider this wave officially launched once onboarding and training of an expanded group of data collectors is complete and the pace of follow-ups picks up with number of children turning 36 months of age. All field activities that predate this registration are considered piloting and have served to iron out remaining logistical, technical, and language issues, and to finalize decisions on tool and item selection. No data have been analyzed, with the exception of measures for which psychometric properties needed to be examined to inform modification and selection decisions.
Age range
36 Months – 38 Months
Sex
ALL
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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
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Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Cognitive Development
Timeframe: 1st of 3 visits at 36 months of age
Executive Function
Timeframe: Visit 1 of the 36-month follow-up