P-1936. Does SARS-CoV-2 Infection or Vaccination Impact Menstrual Health? Results From a Longitudinal Cohort Study Among Military Health System Beneficiaries
Authors: Mayes Caleb , Berjohn Catherine , Byrne Celia , Colombo Rhonda E , Ewers Evan , Flanagan Ryan , Fries Anthony C , Ganesan Anuradha , Jones Milissa , Lalani Tahaniyat , Larson Derek , Lindholm David A , Mende Katrin , Mody Rupal , Maldonado Carlos , Maves Ryan C , Rusiecki Jennifer , Saunders David , Schofield Christina , O’Connell Robert , Simons Mark , Tribble David R , Agan Brian , Burgess Timothy , Pollett Simon , Richard Stephanie A 
Published: January 2025

Abstract

Background
The impact of SARS-CoV-2 infection and vaccination on menstruation is unclear. The goal of this study is to quantify the relationships between history of SARS-CoV-2 vaccination and infection and incident, clinically documented menstrual irregularities using data from the EPICC study in Military Health System (MHS) beneficiaries.Figure 1.Odds of menstrual irregularities associated with having been infected with or vaccinated against SARS-CoV-2 in certain timeframes (30, 90, 180, and 365 days prior to diagnosis or matched timepoint), after controlling for comorbidities in cases and controls matched on race/ethnicity, five-year age group, and BMI category in the Epidemiology, Immunology, and Clinical Characteristics of emerging infectious diseases with pandemic potential (EPICC) cohort.

Methods
This study included 18–50-year-old women who did not have pre-specified characteristics (e.g., pregnancy, breastfeeding, menopause) or pre-existing diagnoses of menstrual irregularities prior to the pandemic in their electronic medical record (MHS Data Repository (MDR)). Cases had a new diagnosis of a menstrual irregularity in the MDR between 3/2020 and 12/2022 and were matched 1:1 with a control of the same race/ethnicity, BMI category, and age category who did not have a menstrual irregularity diagnosis during that same time. Proportions with/without a history of SARS-CoV-2 infection and/or vaccination were compared. A logistic regression model provided estimates of the associations between SARS-CoV-2 infection or vaccination (in 30-, 90-, 180- or 365-days prior to diagnosis or matched timepoint) and diagnosis of menstrual irregularities.Table 1.Matched characteristics in those with and without menstrual irregularities in EPICC (N=249 cases, 249 controls)

Results
There were 270 participants (out of 1,156 women) with incident clinically documented menstrual irregularities identified over 2.8 years (8.3% per year from 3/20 to 12/22). Based on individual matching, 249 cases and controls were included in analyses (N=498, 21 cases did not have a matched control and were dropped) (Tables 1 & 2). Fewer controls than cases had a positive SARS-CoV-2 test in the prior 30, 180, and 365 days, whereas more controls reported being vaccinated in all time periods, but these were not statistically different (p &gt;0.2) (Table 3). No statistically significant associations between 30, 90, 180, or 365-day history of SARS-CoV-2 infection or vaccination and menstrual irregularities were identified (Figure 1).Table 2.Incident menstrual-associated irregularities reported in 249 EPICC participants1 - 11 (4.4%) of the participants had more than one diagnosis

Conclusion
No relationship between recent SARS-CoV-2 infection/vaccination and clinically attended menstrual irregularities was observed in this analysis, but further studies are needed to confirm these findings. Future work will include analyses based on each vaccination and infection event using Cox proportional hazards models.Table 3.Participants’ history of SARS-CoV-2 infection and vaccination among those with and without menstrual irregularities in EPICC. P-values generated using Pearson’s Chi-squared tests.

Disclosures
Ryan C. Maves, MD, AiCuris: Grant/Research Support|Biotest: Grant/Research Support|GeoVax: Grant/Research Support|Shionogi: Advisor/Consultant|Shionogi: Honoraria|Sound Pharmaceuticals: Grant/Research Support Mark Simons, PhD, Astrazeneca: Grant/Research Support Timothy Burgess, MD, MPH, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response Simon Pollett, MBBS, AstraZeneca: The IDCRP and HJF were funded to conduct an unrelated phase III COVID-19 monoclonal antibody immunoprophylaxis trial as part of US Govt COVID Response