The teen period (T-DOT) cohort: a longitudinal study to understand patterns of menstruation and risk factors for iron deficiency in the early post-menarchal years

The National Institute of Child Health and Human Development awarded $631,127 to the Research Institute At Nationwide Children's Hospital on September 1, 2026, for a longitudinal study of menstrual patterns and iron deficiency risk in newly menarchal adolescents under the Child Health and Human Development Extramural Research program (CFDA 93.865).

The recipient is establishing a nationally representative population-level databank using the T-DOT (Teen Period) mobile app, a HIPAA-compliant menstrual tracking application, to document menstrual cycle patterns (frequency, duration, and flow) and identify the frequency, timing, and risk factors for iron deficiency in the early post-menarchal years. The study enrolls 500 adolescents and builds on feasibility demonstrated through a prior NICHD R21 award. The research addresses a gap in age-specific vital sign data for menstruation, particularly in early adolescence, and connects heavy menstrual bleeding to iron deficiency, fatigue, reduced exercise capacity, and cognitive issues.

This is a Project Grant (R01HD117481). Work is performed in Columbus, Ohio. The period of performance runs from September 1, 2026, through May 31, 2031.

Abstract

The menstrual cycle is recognized as a vital sign reflective of overall health in pediatrics. The ability to differentiate between normal and abnormal menstruation is essential because many health issues can manifest as irregularities in menstrual flow, duration, or timing. Early recognition of heavy menstrual bleeding is crucial because IT often leads to iron deficiency (ID), which is linked to fatigue, reduced exercise capacity, and cognitive issues. While age-specific parameters for blood pressure and other vital signs are readily available, data on menstruation, especially in early adolescence, are limited and outdated. Furthermore, while non-medical factors influencing health may affect menstruation and risk of ID, population data from nationally representative cohorts are even more limited. Smartphones and tablets enable greater access to adolescents and decrease barriers to research on menstruation. The objective of this R01 application is to prospectively study newly menarchal adolescents using the T-DOT (teen period) mobile APP to establish a nationally representative population-level databank that informs the expected parameters of the menstrual cycle vital sign, patterns, and risk factors for ID. T-DOT is a teen-friendly, hipaa-compliant menstrual tracking APP that securely transfers data directly to our research team. The results from our nichd R21 award demonstrated feasibility and sustained participant engagement with T-DOT. We are now well-positioned to achieve our objectives through the following aims: 1) establish population menstrual patterns (frequency, duration, and flow) using the T-DOT menstrual tracking APP, and 2) identify the frequency, timing, and risk factors for ID in the early post-menarchal years. Our study population will include 500 adolescents within six months of their first menstrual cycle who are nationally representative with respect to race, ethnicity, and body weight. Participants will track their menstrual patterns using the T-DOT APP over two years and complete virtual study visits every eight months, which will include at- home ID screening. Our rationale for this research is that using smartphones to identify population patterns among young adolescents offers an opportunity to detect abnormal menstruation earlier and to prompt interventions to enhance reproductive health and quality of life. Our work is innovative because we will recruit a nationally representative sample from across the united states, focus on the early gynecological years prospectively, and utilize a decentralized approach to increase feasibility and reduce participant burden. Completion of this work will yield the following expected outcomes: 1) a contemporary nationally representative population-level databank to inform the expected parameters of the menstrual cycle vital sign in early post- menarchal adolescents, and 2) identification of the frequency of and risk factors for ID in adolescent females to identify patients who would benefit from early laboratory screening. Our work is responsive to the 2024-2028 NIH-wide strategic plan for research on women's health, which highlights the need for focused investigation of female reproductive health, including menstruation.