# Determining the impact of COVID-19 vaccination on the menstrual cycle

> **NIH NIH R01** · OREGON HEALTH & SCIENCE UNIVERSITY · 2021 · $296,124

## Abstract

Project Summary
This supplement to the parent award R01HD089957 will use several large preexisting US-based datasets to
determine the impact of COVID-19 vaccine on menstrual health. While the parent award focuses on menstrual
cycle changes with direct measures of ovulation and obesity as the main exposure, this supplement will focus
on the COVID-19 vaccine as the main exposure, menstrual cycle changes, and indirect measures of ovulation.
We will utilize similar scientific methods approved of in Specific Aims 1 and 2 of the parent award including
prospective tracking of the menstrual cycle using validated measures and the inclusion of reproductive-age
women of varying body mass index with regular menstrual cycles not using hormonal contraception.
Public concern is mounting regarding the possible association between COVID-19 and menstrual health. This
concern could lead to vaccine hesitancy for individuals and their families; a threat to achieving sufficient rates
of vaccination and enabling windows of opportunity for the development of additional virulent variants.
Menstrual cyclicity is an overt sign of health and fertility. Thus, our ability to gain a greater understanding of
whether or not an association exists between COVID-19 vaccine and menstrual health is critical for the
physical and mental well-being of those who menstruate, their community, and our greater public health.
The goal of this supplement “COVID19 vaccination and Menstruation” is to determine if COVID-19
vaccination causes menstrual disturbances. Our primary outcome is the within-woman difference in mean
menstrual cycle length (in days) pre- and post-vaccination or unvaccinated as well as secondary outcomes
related to menstrual cycle timing and severity of vaccine response and changes in menstrual characteristics
(e.g. flow, length, pain, associated symptoms, intermenstrual bleeding). We will perform a retrospective
analysis of prospectively tracked menstrual cycle data utilizing validated measures pre- and post-COVID-19
vaccination or over similar time period for the unvaccinated group. We will develop a multi-variable logistic
regression model considering all available potential confounders including but not limited to vaccine type, BMI,
age, race/ethnicity, life stressors, etc. Our team has received the commitment of two leading online menstrual
cycle tracking platforms with the built-in user approval to provide this de-identified data for research purposes
plus the ability to survey these users to obtain additional data. As of June 2021, they report a cumulative
number of active US reproductive age users with ‘natural’ cycles (no hormonal contraception) of approximately
2 million.

## Key facts

- **NIH application ID:** 10429816
- **Project number:** 3R01HD089957-04S1
- **Recipient organization:** OREGON HEALTH & SCIENCE UNIVERSITY
- **Principal Investigator:** ALISON B EDELMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $296,124
- **Award type:** 3
- **Project period:** 2016-12-22 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10429816

## Citation

> US National Institutes of Health, RePORTER application 10429816, Determining the impact of COVID-19 vaccination on the menstrual cycle (3R01HD089957-04S1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10429816. Licensed CC0.

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