# An internet-based preconception cohort study in North America and Denmark

> **NIH NIH R01** · BOSTON UNIVERSITY MEDICAL CAMPUS · 2021 · $299,328

## Abstract

ABSTRACT
The proposed supplement responds to “COVID19 Vaccination and Menstruation” (NOT-HD-21-035). Clinical
trials did not evaluate the influence SARS-CoV-2 vaccine on menstruation and anecdotal reports of menstrual
changes after SARS-CoV-2 vaccination have circulated widely on social media, raising concerns about vaccine
safety among the public. Pregnancy Study Online (PRESTO) is an NIH-funded prospective cohort study that
enrolls women trying to conceive and follows them from preconception through 6 months after delivery
(R01HD086742). Eligible female participants are aged 21-45 years, residents of North America, trying to
conceive, and not using contraception or fertility treatment. During 6/2013-6/2021, PRESTO has enrolled more
than 15,500 female participants. All questionnaires are completed online and data collection continued during
the COVID-19 pandemic. In April 2020, we added new questions on COVID-19 infection and stressors related
to the pandemic, including changes in lifestyle, behaviors and health care, and in January 2021, we added
questions on SARS-CoV-2 vaccination (ever vaccinated, type of vaccine, and date of each shot). Since the
study's inception, women have reported baseline data about their typical menstrual characteristics while not
using hormones. After enrollment, women are offered a premium membership to Kindara.com, a menstrual
charting app, in which they report day-specific menstrual data in real-time. On each bimonthly questionnaire
(administered for up to 12 months), women report additional data about their most recent menstrual cycles. We
will use the above prospectively-collected data to examine the extent to which SARS-CoV-2 vaccination is
associated with changes in menstruation during 6 cycles of follow-up. Specifically, we will evaluate the
association between SARS-CoV-2 vaccination and cycle irregularity, cycle length, intensity of bleed, duration of
bleed, intermenstrual spotting/bleeding, and pain associated with menses. We will consider various windows of
possible effects and identify the duration of any observed changes. We will control for several confounders,
including COVID-19-related stressors. Among 1,800 U.S. participants who completed ≥1 follow-up questionnaire
after 12/14/2020, we will compare menstrual characteristics between vaccinated and unvaccinated groups; we
will also perform a self-matched analysis among 800 vaccinated women (pre- vs. post-vaccination). In the subset
of ≥400 women who reported day-specific menstrual data using Kindara, we will characterize vaccine-related
changes in menstruation. Our interdisciplinary research team has published extensively on vaccine-related
health effects and menstrual characteristics, many of which are based on PRESTO data, and we have the
expertise necessary to study these research questions. Given our ongoing prospective data collection throughout
the pandemic, our successful recruitment of a large, diverse population of women not using hormones, and...

## Key facts

- **NIH application ID:** 10434313
- **Project number:** 3R01HD086742-05S2
- **Recipient organization:** BOSTON UNIVERSITY MEDICAL CAMPUS
- **Principal Investigator:** ELIZABETH E HATCH
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $299,328
- **Award type:** 3
- **Project period:** 2016-09-14 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10434313

## Citation

> US National Institutes of Health, RePORTER application 10434313, An internet-based preconception cohort study in North America and Denmark (3R01HD086742-05S2). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10434313. Licensed CC0.

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