Covid-19 vaccination and menstrual cycle length in the Apple Women's Health Study

A Prospective Study of the Relationship of COVID-19 Vaccination to Menstrual Cycle Characteristics in Adolescent Girls

PURPOSE

The current study aimed to evaluate the impact of the COVID-19 booster vaccine on menstrual cycle characteristics in adolescent girls (aged 13-20) compared to those who did not receive a booster vaccine.

METHODS

This prospective study measured menstrual cycle length for three cycles prior to and four cycles after vaccination (booster group), seven cycles without vaccination (control group). Menstrual flow, menstrual pain, and menstrual symptoms were assessed at baseline and monthly for 3 months. Stress was assessed at baseline using the PROMIS Pediatric Psychological Stress Experiences scale. Generalized linear mixed effects models were used to examine the changes in menstrual characteristics.

RESULTS

65 adolescent girls (47 booster; 18 control) were recruited via social media and from ongoing studies in the United States. Girls in the booster group experienced shorter postbooster cycles by an average 5.35 days (p = .03) compared to prebooster cycle lengths, specifically in the second postbooster cycle, while the control group did not show any changes in cycle length pre-to postbooster. Participants who received the booster in the follicular phase had shorter mean postbooster cycle length (p = .0157) compared to their prebooster cycle length. Higher stress was associated with shorter cycles (p = .03) and increased menstrual symptoms (p = <.001), regardless of group. There were no differences in menstrual flow, menstrual pain, or menstrual symptoms in either group.

DISCUSSION

The COVID-19 booster vaccine was associated with shorter cycles in adolescent girls. These data demonstrate the need for further investigation regarding potential mechanisms of these observed changes.

Adverse Menstrual Events Reported After and Before (or Without) COVID-19 Vaccination: A Systematic Review and Meta-Analysis of Comparative Observational Studies

BACKGROUND

Reports of adverse menstrual events emerged during the COVID-19 vaccination campaign in multiple countries. This raised the question whether these reports were caused by the vaccines. The aim of this systematic review was to evaluate comparative studies on this topic (registered at PROSPERO [CRD42022324973]).

METHODS

We included observational studies such as cohort studies and surveys comparing the response to self-reported questionnaires between post- versus pre-vaccination data. PubMed and Cochrane Library searches were conducted on 1 September 2023. The primary outcome was the incidence of any prespecified adverse menstrual event, and the outcome measure was the risk ratio. The meta-analysis was conducted by using the Mantel-Haenszel method and the random effects model. We summarized the results on risk factors as well as key findings of the studies included.

RESULTS

We retrieved 161 references from electronic databases and additional sources such as references lists. Of those, we considered 21 comparative observational studies. The meta-analysis of any adverse menstrual adverse event reported in 12 studies resulted in a pooled estimate (risk ratio 1.13; 95% CI, 0.96-1.31) that did not favor any group. The analysis was constrained by considerable clinical and statistical heterogeneity. Risk factors for self-reported menstrual changes included a history of COVID-19 infection, the concern about COVID-19 vaccines, smoking, previous cycle irregularities, depression, and stress, and other issues.

CONCLUSIONS

The risk ratio did not favor any group and heterogeneity was prevalent among the studies. Most studies suggested that the reported changes were temporary, minor, and nonserious.

The association of COVID-19 vaccination and menstrual health: A period-tracking app-based cohort study

Background

In initial COVID-19 clinical trials, menstrual health was not formally monitored, yet anecdotal reports of menstruation changes surfaced on social media. This study aims to assess the association between COVID-19 vaccines and menstruation using Clue, a period-tracking application.

Study design

A survey assessing demographics, menstrual health, stress levels, and COVID-19 vaccination was sent to Clue users between 12/7/2021 and 2/9/2022. Inclusion criteria were (1) 18 years or older (2) currently menstruating (3) not pregnant or breastfeeding since 1/2020. Menstrual data was collected for each participant. Users with cycle lengths more than 90 days were excluded. Cycle lengths were calculated for the 6-month average pre-vaccination (PRIOR), the cycle during which vaccination was administered (DURING), the cycle following DURING (AFTER1), and the cycle following AFTER1 (AFTER2). For periods, individuals were stratified based on whether vaccination was received during their menstrual period (DURING). Period lengths were additionally calculated for the 6-month average pre-vaccination (PRIOR), the first period following vaccination (AFTER1), and the period following AFTER1 (AFTER2). For unvaccinated participants, an index date (4/1/2022) was used to similarly designate menstrual cycles and periods. For each participant, cycle length changes for DURING, AFTER1, and AFTER2 compared to PRIOR were determined. Student's t-test compared the mean of these changes between vaccinated and unvaccinated groups.

Results

Of 7,559 participants, 6,897 (91 %) were vaccinated. Compared to PRIOR, individuals vaccinated during their menstrual period demonstrated a statistically significant increase in the DURING period length, but not AFTER1 (p = 0.463) and AFTER2 (p = 0.692). No statistically significant changes were observed in period lengths of those vaccinated in between periods or in cycle lengths overall.

Conclusion

A small but statistically significant change in period length was observed only in individuals vaccinated for COVID-19 during their menstrual period. Providers can better counsel menstruating individuals to reduce vaccine misinformation.

Measurement of changes to the menstrual cycle: A transdisciplinary systematic review evaluating measure quality and utility for clinical trials

Despite the importance of menstruation and the menstrual cycle to health, human rights, and sociocultural and economic wellbeing, the study of menstrual health suffers from a lack of funding, and research remains fractured across many disciplines. We sought to systematically review validated approaches to measure four aspects of changes to the menstrual cycle-bleeding, blood, pain, and perceptions-caused by any source and used within any field. We then evaluated the measure quality and utility for clinical trials of the identified instruments. We searched MEDLINE, Embase, and four instrument databases and included peer-reviewed articles published between 2006 and 2023 that reported on the development or validation of instruments assessing menstrual changes using quantitative or mixed-methods methodology. From a total of 8,490 articles, 8,316 were excluded, yielding 174 articles reporting on 94 instruments. Almost half of articles were from the United States or United Kingdom and over half of instruments were only in English, Spanish, French, or Portuguese. Most instruments measured bleeding parameters, uterine pain, or perceptions, but few assessed characteristics of blood. Nearly 60% of instruments were developed for populations with menstrual or gynecologic disorders or symptoms. Most instruments had fair or good measure quality or clinical trial utility; however, most instruments lacked evidence on responsiveness, question sensitivity and/or transferability, and only three instruments had good scores of both quality and utility. Although we took a novel, transdisciplinary approach, our systematic review found important gaps in the literature and instrument landscape, pointing towards a need to examine the menstrual cycle in a more comprehensive, inclusive, and standardized way. Our findings can inform the development of new or modified instruments, which-if used across the many fields that study menstrual health and within clinical trials-can contribute to a more systemic and holistic understanding of menstruation and the menstrual cycle.

GP consultations for menstrual disorders after COVID-19 vaccination - A self-controlled cohort study based on routine healthcare data from the Netherlands

INTRODUCTION

Several studies described that COVID-19 vaccinations can cause menstrual disorders. Our study aimed to describe whether this also resulted in more general practitioner (GP) consultations for menstrual disorders after COVID-19 vaccination, based on a large cohort study.

METHODS

A retrospective self-controlled cohort study was performed including vaccinated women in 2021 aged 12-49 years from two large, representative GP databases in the Netherlands. Incidence rates and incidence rate ratio's (IRR) were calculated using Poisson regression, adjusting for SARS-CoV-2 infection as time-varying confounder. The exposed period was set at maximum six months after each COVID-19 vaccination and the non-exposed period was defined as all-time outside the exposed period.

RESULTS

The cohort included 631,802 women, of which 18,986 (3 %) consulted the GP for a menstrual disorder during 2021. Increased GP consultations were observed among 12-14 year olds for amenorrhea/hypomenorrhea/oligomenorrhea (IRR: 1.85, 95 % CI: 1.30-2.65) and irregular/frequent menstruation (IRR: 1.33, 95 % CI: 1.06-1.69) after COVID-19 vaccination in general, and after Pfizer/BioNTech vaccination (IRR: 1.87, 95 % CI: 1.31-2.67 for amenorrhea/hypomenorrhea/oligomenorrhea and IRR: 1.35, 95 % CI: 1.06-1.70 for irregular/frequent menstruation). Persons from this age group were in general also vaccinated with Pfizer/BioNTech. No increase in the frequency of GP consultations were observed for older age groups, other vaccine brands, and potential risk groups.

CONCLUSION

For the majority of women, no increased GP consultations for menstrual disorders was found. Solely for the youngest age group (12-14 year olds) increased GP consultations for specific types of menstrual disorders was found after Pfizer/BioNTech vaccination.

Association between COVID-19 vaccination and menstruation: a state of the science review

INTRODUCTION

Menstrual health is a key patient-reported outcome beyond its importance as a general indicator of health and fertility. However, menstrual function was not measured in the clinical trials of COVID-19 vaccines. The purpose of this review was to synthesise the existing literature on the relationship between COVID-19 vaccination and menstrual health outcomes.

METHODS

A PubMed search to 31 October 2023 identified a total of 53 publications: 11 prospective cohort studies, 11 retrospective cohort studies or registry-based cohort studies, and 31 cross-sectional or retrospective case-control studies.

RESULTS

Identified studies were generally at moderate-to-high risk of bias due to retrospective design, interviewer bias, and failure to include a non-vaccinated control group. Nonetheless, the bulk of the literature demonstrates that COVID-19 vaccine is associated with temporary changes in menstrual characteristics (cycle length and flow) and menstrual pain. Follicular phase (at the time of vaccination) is associated with greater increases in cycle length. Evidence suggests temporary post-vaccine menstrual changes in adolescents, abnormal vaginal bleeding in postmenopausal individuals, and a potential protective effect of using hormonal contraception.

CONCLUSIONS

In this review we found evidence supporting an association between the COVID-19 vaccine and menstrual health outcomes. Given the importance of menstrual function to overall health, we recommend that all future vaccine trials include menstruation as a study outcome. Future vaccine studies should include rigorous assessment of the menstrual cycle as an outcome variable to limit sources of bias, identify biological mechanisms, and elucidate the impact of stress.

The direct effect of SARS-CoV-2 virus vaccination on human ovarian granulosa cells explains menstrual irregularities

Following administration of the SARS-CoV-2 vaccine, many women worldwide reported short-term menstrual irregularities. Although menstrual bleeding, "the fifth vital sign", is experienced by more than 300 million people on any given day worldwide, these changes were only partially studied. Irregular periods are important well beyond fertility and the discomfort they impose; they are associated with the risk of cardiovascular morbidity, chronic diseases, and premature mortality. Pre-clinical examination of the vaccine polymeric envelope indicates its accumulation in the ovaries. The somatic endocrine cells of the ovarian follicle - the granulosa cells (GCs)-participate in the strict hypothalamic-pituitary-ovarian (HPO) feedback loop that governs the menstrual cycle via endocrine and paracrine regulators, as AMH and Inhibins. We aimed to unravel the direct effect of the COVID-19 vaccine on GCs and link their post-vaccine activity to changes in menstrual patterns. Human primary GCs exposed in-vitro to the Pfizer COVID-19 vaccine BNT162b2, demonstrated no change in their viability but altered mRNA transcripts, specifically of the regulatory key factors: InhibinB was upregulated, whereas AMH was downregulated. We further examined pre- and post-vaccination blood samples from individual women and found a 2-3 folds change in the post-vaccination FSH/InhibinB protein level ratio, compared to their pre-vaccination values. This altered expression of InhibinB could significantly impact the HPO axis in vaccinated women and may ultimately influence the endometrium cyclicity, manifested clinically by the commonly reported changes in menstrual bleeding patterns.

Association between Covishield vaccine and menstrual disturbance. Findings from a cross-sectional study among participants of Zero TB cohort in India

BACKGROUND

The association between covid-19 vaccine and menstrual disturbance is unclear.

METHODS

An in-person cross-sectional survey among female members ≥ 18 years enrolled in an ongoing Zero TB prospective cohort in Northern India who had received one or two doses of covid-19 vaccine was conducted to study the characteristics and association of menstrual disturbance within six months of receiving Covishield.

RESULTS

Between June 29 and September 5, 2021, 339 females ≥ 18 years of age were administered the survey. Median age was 30 (IQR: 22-39) years; 84 % were between 18 and 49 and 16 % were ≥ 50 years old. There were 152 college students, 27 healthcare workers, and 160 nuns. Forty-two women (12 %) had received one dose and 297 (88 %) had received two doses of Covishield. Overall, 66 (20 %) women reported experiencing menstrual disturbance after receiving Covishield vaccine. The problems included early menstruation: 6 % (n = 19/339); late menstruation: 4 % (n = 14/339); and heavier bleeding: 5 % (n = 17/339). Disturbances lasted for less than seven days and cycles normalized in 1-3 months. There was no post-menopausal bleeding. There was no significant difference in menstrual disturbance based on receiving one vs. two doses of Covishield (OR: 1.58; 95 % CI: 0.55-4.57; p = 0.381). History of SARS-CoV-2 infection was not associated with the development of menstrual disturbance among the vaccinees (OR: 0.63; 95 % CI: 0.24-1.73; p = 0.379). Presence of emotional disturbance at baseline (OR: 31; 95 % CI: 3.52-267; p = 0.002) or previous history of dysmenorrhea (OR: 41; 95 % CI: 8.7-196; p < 0.001) was associated with menstrual disturbance in the vaccinees, indicating their potential to confound or bias study results.

CONCLUSION

Menstrual problems were reported by Covishield vaccinees, but they were minor and reversible within three months and do not constitute a ground for vaccine hesitancy. Studies designed to assess causal link taking care to avoid selection bias or confounding are needed.

Menstrual Cycle Disturbances after COVID-19 Vaccination: A Cross-Sectional Study

BACKGROUND

Following COVID-19 vaccination, some women suffered from menstrual cycle disturbances. This study aimed to investigate menstrual cycle disturbances after COVID-19 vaccination in women of reproductive age.

MATERIALS AND METHODS

This cross-sectional study was performed on 407 vaccinated women in the vaccination center of Imam Hossein Hospital (Tehran, Iran) between October 2021 and October 2022. They were interviewed based on a research-made checklist which consisted of two areas of questions about the baseline characteristics of participants and menstrual cycle characteristics to explore menstrual characteristics following COVID-19 vaccination.

RESULTS

The prevalence of menstrual disturbances was higher after the third dose (38.3%) compared with the second (27.9%) and first (17.7%) doses (P<0.001). After the first dose, a history of polycystic ovarian syndrome [PCOS, odds ratio (OR)=7.35, 95% confidential interval (CI)= (3.64-14.82), P<0.001] and menstrual disturbances with unknown etiology [OR=15.23, 95% CI=(6.30-36.80), P<0.001] could predict menstrual disturbances. After the second dose, a history of menstrual disturbances with unknown etiology [OR=3.83, 95% CI=(1.47-9.94), P=0.006] and menstrual disturbances after the first dose [OR=201.96, 95% CI= (40.99-994.90), P<0.001] were predictors of menstrual disturbances. After the third dose, a history of menstrual disturbances with unknown etiology [OR=3.09, 95% CI= (1.00-9.52), P=0.048], menstrual disturbances after the first [OR=9.82, 95% CI=(1.38-69.69), P=0.022] and second [OR=7.83, 95% CI=(1.46-41.92), P=0.016] doses could predict menstrual disturbances.

CONCLUSION

We detected that many women experienced various menstrual disturbances after vaccination against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Furthermore, a history of menstrual abnormalities (before COVID-19 vaccination and following the previous doses of these vaccines) was associated with developing menstrual disturbances.

Saudi Women's Perception of the Effect of COVID-19 Infection and Vaccination on Menstrual Cycle Length

Background and Aim

This study was conducted in the Kingdom of Saudi Arabia to investigate the effects of the COVID-19 virus and the vaccine on menstrual periods. The data from this study would increase people's awareness of the impacts of the virus and its vaccines on menstrual periods and serve as a reference for further studies.

Materials and Methods

The data was collected through a web link where standardized close-ended questionnaires were distributed via several social media platforms in Saudi Arabia.

Results

The study included 691 respondents, with 411 women meeting the inclusion criteria. The majority of participants fell within the age range of 35-45, and 64% held at least a bachelor's degree. The Eastern region of Saudi Arabia had the highest percentage of participants, while the Northern region had the lowest. More than half of the participants were married, and 57% reported having been infected with COVID-19. The vast majority (99%) had received the COVID-19 vaccine, primarily the Pfizer/BioNTech vaccine. The study assessed the association between menstruation experience and symptoms in three situations: before infection or vaccination, after COVID-19 infection, and after vaccination. Differences were observed in the length of the menstrual cycle and flow, but no statistically significant differences were found for pelvic and back pain.

Conclusions

The result of this current study suggests that COVID-19 infection and/or vaccination has several effects on the menstrual cycle which changes in menses are minimal and transient.

The Role of the European Medicines Agency in the Safety Monitoring of COVID-19 Vaccines and Future Directions in Enhancing Vaccine Safety Globally

The European Union (EU) regulatory network was at the forefront of the safety monitoring of COVID-19 vaccines during the pandemic. An unprecedented number of case reports of suspected adverse reactions after vaccination called for huge efforts for the assessment of this safety information, to ensure that any possible risks were detected and managed as early as possible, while ruling out coincidental but temporally related adverse health outcomes. We describe the role of the European Medicines Agency alongside the EU regulatory network in the safety monitoring of the COVID-19 vaccines, and provide an insight into challenges, particularities and outcomes of the scientific assessment and regulatory decisions in the complex, dynamic international environment of the pandemic. We discuss the flexible procedural tools that were used to ensure an expedited scientific assessment of safety issues, and subsequent updates of the product information (i.e., labelling) when available evidence (e.g., spontaneous reports, findings from observational studies and/or scientific literature) suggested that causal association is at least a reasonable possibility. The safety monitoring was accompanied by enhanced transparency measures, proactive communication, and easy access to information, which played a key role in public reassurance. The pandemic has been a powerful booster for worldwide collaboration, exchange of information and work-sharing. The safety monitoring of COVID-19 vaccines continues, and the lessons learned will be applied in future safety reviews, as well as future health emergencies.

Abnormal uterine bleeding diagnoses and care following COVID-19 vaccination

BACKGROUND

There is evidence suggesting that COVID-19 vaccination may be associated with small, transitory effects on uterine bleeding, possibly including menstrual timing, flow, and duration, in some individuals. However, changes in health care seeking, diagnosis, and workup for abnormal uterine bleeding in the COVID-19 vaccine era are less clear.

OBJECTIVE

This study aimed to assess the impact of COVID-19 vaccination on incident abnormal uterine bleeding diagnosis and diagnostic evaluation in a large integrated health system.

STUDY DESIGN

Using segmented regression, we assessed whether the availability of COVID-19 vaccines was associated with changes in monthly, population-based rates of incident abnormal uterine bleeding diagnoses relative to the prepandemic period in health system members aged 16 to 44 years who were not menopausal. We also compared clinical and demographic characteristics of patients diagnosed with incident abnormal uterine bleeding between December 2020 and October 13, 2021 by vaccination status (never vaccinated, vaccinated in the 60 days before diagnosis, vaccinated >60 days before diagnosis). Furthermore, we conducted detailed chart review of patients diagnosed with abnormal uterine bleeding within 1 to 60 days of COVID-19 vaccination in the same time period.

RESULTS

In monthly populations ranging from 79,000 to 85,000 female health system members, incidence of abnormal uterine bleeding diagnosis per 100,000 person-days ranged from 8.97 to 19.19. There was no significant change in the level or trend in the incidence of abnormal uterine bleeding diagnoses between the prepandemic (January 2019-January 2020) and post-COVID-19 vaccine (December 2020-December 2021) periods. A comparison of clinical characteristics of 2717 abnormal uterine bleeding cases by vaccination status suggested that abnormal bleeding among recently vaccinated patients was similar or less severe than abnormal bleeding among patients who had never been vaccinated or those vaccinated >60 days before. There were also significant differences in age and race of patients with incident abnormal uterine bleeding diagnoses by vaccination status (Ps<.02). Never-vaccinated patients were the youngest and those vaccinated >60 days before were the oldest. The proportion of patients who were Black/African American was highest among never-vaccinated patients, and the proportion of Asian patients was higher among vaccinated patients. Chart review of 114 confirmed postvaccination abnormal uterine bleeding cases diagnosed from December 2020 through October 13, 2021 found that the most common symptoms reported were changes in timing, duration, and volume of bleeding. Approximately one-third of cases received no diagnostic workup; 57% had no etiology for the bleeding documented in the electronic health record. In 12% of cases, the patient mentioned or asked about a possible link between their bleeding and their recent COVID-19 vaccine.

CONCLUSION

The availability of COVID-19 vaccination was not associated with a change in incidence of medically attended abnormal uterine bleeding in our population of over 79,000 female patients of reproductive age. In addition, among 2717 patients with abnormal uterine bleeding diagnoses in the period following COVID-19 vaccine availability, receipt of the vaccine was not associated with greater bleeding severity.

The Evaluation of Menstrual Alterations in Mexican Women After Vaccination Against COVID-19

Introduction Menstrual changes after COVID-19 vaccination suggest a secondary connection to the immune response to vaccination rather than a specific component of the vaccine. The evaluation of these alterations in women with the same and multiple vaccination schedules will provide valuable information. Methods An observational, cross-sectional study was carried out; data were collected through a survey of 164 vaccinated women at the American British Cowdray (ABC) Santa Fe Medical Center Hospital in Mexico City. The survey was validated by the Delphi method. Results The survey was applied from March 2023 to February 2024. Post-vaccination menstrual alterations occurred in 48.1%; the most frequent alteration was menorrhagia in 20.7% and pain accompanied by menstruation in 27.4%. Fifty-seven percent had a history of previous COVID-19 infection. There were no significant associations between changes in menstrual bleeding after vaccination, history of COVID-19 infection, and age group (p>0.9). However, women who received multiple doses of vaccines had a higher risk of suffering abnormalities in bleeding by 36.6%. Conclusion The incidence of menstrual disorders in this study post COVID-19 vaccination was 49%. Menstrual alterations in patients who received multiple doses and a single regimen were similar at 47% and 48%, where there is no statistical significance. The greatest number of menstrual alterations was seen in the first dose at 36%, probably due to the immunity they acquired after the different types of vaccination. Vaccination is a very effective way to prevent the severity of COVID-19 infection; it has an impact on menstrual bleeding in terms of menorrhagia and metrorrhagia. Vaccination against COVID-19 is associated with small changes in the menstrual cycle, without statistical significance. Women receiving the first dose of the vaccine had changes in the amount of bleeding specifically the amount.

Timing of Coronavirus Disease 2019 (COVID-19) Vaccination and Effects on Menstrual Cycle Changes

OBJECTIVE

To assess whether menstrual cycle timing (follicular or luteal phase) of coronavirus disease 2019 (COVID-19) vaccine administration is associated with cycle length changes.

METHODS

We used prospectively collected (2021-2022) menstrual cycle tracking data from 19,497 reproductive-aged users of the application "Natural Cycles." We identified whether vaccine was delivered in the follicular or luteal phase and also included an unvaccinated control group. Our primary outcome was the adjusted within-individual change in cycle length (in days) from the average of the three menstrual cycles before the first vaccination cycle (individuals in the unvaccinated control group were assigned a notional vaccine date). We also assessed cycle length changes in the second vaccination cycle and whether a clinically significant change in cycle length (8 days or more) occurred in either cycle.

RESULTS

Most individuals were younger than age 35 years (80.1%) and from North America (28.6%), continental Europe (33.5%), or the United Kingdom (31.7%). In the vaccinated group, the majority received an mRNA vaccine (63.8% of the full sample). Individuals vaccinated in the follicular phase experienced an average 1-day longer adjusted cycle length with a first or second dose of COVID-19 vaccine compared with their prevaccination average (first dose: 1.00 day [98.75% CI, 0.88-1.13], second dose: 1.11 days [98.75% CI, 0.93-1.29]); those vaccinated in the luteal phase and those in the unvaccinated control group experienced no change in cycle length (respectively, first dose: -0.09 days [98.75% CI, -0.26 to 0.07], second dose: 0.06 days [98.75% CI, -0.16 to 0.29], unvaccinated notional first dose: 0.08 days [98.75% CI, -0.10 to 0.27], second dose: 0.17 days [98.75% CI, -0.04 to 0.38]). Those vaccinated during the follicular phase were also more likely to experience a clinically significant change in cycle length (8 days or more; first dose: 6.8%) than those vaccinated in the luteal phase or unvaccinated (3.3% and 5.0%, respectively; P <.001).

CONCLUSION

COVID-19 vaccine-related cycle length increases are associated with receipt of vaccination in the first half of the menstrual cycle (follicular phase).

COVID-19 and abnormal uterine bleeding: potential associations and mechanisms

The impact of COVID-19 on menstruation has received a high level of public and media interest. Despite this, uncertainty exists about the advice that women and people who menstruate should receive in relation to the expected impact of SARS-CoV-2 infection, long COVID or COVID-19 vaccination on menstruation. Furthermore, the mechanisms leading to these reported menstrual changes are poorly understood. This review evaluates the published literature on COVID-19 and its impact on menstrual bleeding, discussing the strengths and limitations of these studies. We present evidence consistent with SARS-CoV-2 infection and long COVID having an association with changes in menstrual bleeding parameters and that the impact of COVID vaccination on menstruation appears less significant. An overview of menstrual physiology and known causes of abnormal uterine bleeding (AUB) is provided before discussing potential mechanisms which may underpin the menstrual disturbance reported with COVID-19, highlighting areas for future scientific study. Finally, consideration is given to the effect that menstruation may have on COVID-19, including the impact of the ovarian sex hormones on acute COVID-19 severity and susceptibility and reported variation in long COVID symptoms across the menstrual cycle. Understanding the current evidence and addressing gaps in our knowledge in this area are essential to inform public health policy, direct the treatment of menstrual disturbance and facilitate development of new therapies, which may reduce the severity of COVID-19 and improve quality of life for those experiencing long COVID.

Messenger RNA Therapy for Female Reproductive Health

Female reproductive health has traditionally been an underrepresented area of research in the drug delivery sciences. This disparity is also seen in the emerging field of mRNA therapeutics, a class of medicines that promises to treat and prevent disease by upregulating protein expression in the body. Here, we review advances in mRNA therapies through the lens of improving female reproductive health. Specifically, we begin our review by discussing the fundamental structure and biochemical modifications associated with mRNA-based drugs. Then, we discuss various packaging technologies, including lipid nanoparticles, that can be utilized to protect and transport mRNA drugs to target cells in the body. Last, we conclude our review by discussing the usage of mRNA therapy for addressing pregnancy-related health and vaccination against sexually transmitted diseases in women. Of note, we also highlight relevant clinical trials using mRNA for female reproductive health while also providing their corresponding National Clinical Trial identifiers. In undertaking this review, our aim is to provide a fundamental background understanding of mRNA therapy and its usage to specifically address female health issues with an overarching goal of providing information toward addressing gender disparity in certain aspects of health research.

Prolongation of the Menstrual Cycle After Receipt of the Primary Series and Booster Doses of mRNA Coronavirus Disease 2019 (COVID-19) Vaccination

OBJECTIVE

To quantitatively evaluate the effect of a booster vaccination dose against coronavirus disease 2019 (COVID-19) on menstrual cycle in a large-scale retrospective cohort study using a menstrual cycle tracking smartphone application (app).

METHODS

Prospectively or retrospectively recorded data, including the start and finish dates of menstrual cycles, were collected with the app. Detailed data on vaccinations, side effects, and participants' characteristics were retrospectively collected from a questionnaire on the app. For each COVID-19 vaccination shot (first, second, and third), within-individual changes in menstrual cycle length up to the fourth postvaccination cycle were evaluated.

RESULTS

Among the 7,376 and 6,873 participants who had the first and second COVID-19 vaccine doses in different menstrual cycles, respectively, menstrual cycles immediately after the vaccination (first postvaccination cycles) were an average of 0.22 days (95% CI, 0.06-0.39) and 0.37 days (95% CI, 0.20-0.54) longer than the prevaccination cycle. In contrast, among the 1,672 participants who received the first and second doses in the same cycle, the first postvaccination cycle was an average of 4.21 days (95% CI, 3.69-4.72) longer. The second to fourth postvaccination cycles returned to the level of the prevaccination cycle. However, among the 4,768 participants who had the third COVID-19 vaccine dose, the menstrual cycle immediately after the vaccination was an average of 1.20 days (95% CI, 1.00-1.40) longer, with prolongation of cycles of 0.27 days (95% CI, 0.10-0.44) to 0.41 days (95% CI, 0.22-0.59) persisting from the second to the fourth postvaccination cycle.

CONCLUSION

The booster shot against COVID-19 may have a greater and longer-lasting effect on menstrual cycles than the primary-series shots. Although the effect size was small, evidence on the side effects of immunization on menstruation should be accumulated.

Prevalence of menstrual irregularities after coronavirus disease 2019 vaccination: A cross-sectional study in the Eastern Province, Saudi Arabia

BACKGROUND

Reports indicate that there are menstrual cycle disturbances following coronavirus disease 2019 (COVID-19) vaccination. The present study explored the prevalence of menstrual irregularities after COVID-19 vaccination and the association of menstrual irregularities with vaccine type, doses, immediate adverse effects, history of COVID-19 infection, and its severity.

MATERIALS AND METHODS

For this cross-sectional study, 406 women of reproductive age completed an online survey about the postvaccine changes in their menstruation (cycle duration, bleeding days, and bleeding amount), COVID-19 vaccine history (doses, type of vaccine, and immediate adverse effects), history of COVID-19 infection, and its severity. Data was analyzed using SPSS; descriptive statistics were computed and Chi-square test, and binary logistic regression analysis were performed.

RESULTS

Of the total 406 women, 45% reported postvaccine changes in their menstrual cycle. The most common menstrual change was increased dysmenorrhea (68%), followed by an increase in the length of the cycle (52%). There was a significant association between postvaccine menstrual changes and the age, marital status, and family history of menstrual irregularities. No association was observed between postvaccine menstrual changes and COVID-19 vaccine-and COVID-19 infection-related variables. As per the best-fit model of our predictors, the odds of having postvaccine menstrual changes were 0.41 times less in "single" women (confidence interval [CI] = 0.26-0.27; P < 0.001) and 1.714 times greater in women who had a "family history of menstrual irregularities" (CI = 1.092-2.690; P = 0.02), respectively.

CONCLUSION

A substantial number of women complained of postvaccine menstrual changes regardless of their age, type of COVID-19 vaccine, doses, immediate adverse effects, and COVID-19 infection history/severity. Being "single" decreased the probability, whereas having a family history of menstrual irregularities increased the probability significantly of having postvaccine menstrual changes.

Associations Among Menstrual Cycle Length, Coronavirus Disease 2019 (COVID-19), and Vaccination

OBJECTIVE

To assess whether coronavirus disease 2019 (COVID-19) is associated with menstrual cycle length changes and, if so, how that compares with those undergoing vaccination or no event (control).

METHODS

We conducted a retrospective cohort analysis in which we analyzed prospectively tracked cycle-length data from users of a period tracker application who also responded to a survey regarding COVID-19 symptoms and vaccination. We restricted our sample to users aged 16-45 years, with normal cycle lengths (24-38 days) and regular tracking behavior during the five cycles around COVID-19 symptoms or vaccination or a similar time period for those experiencing no event (control group). We calculated the within-user change in cycle length (days) from the three consecutive cycles preevent average (either vaccination, disease, or neither; cycles 1-3) to the event (cycle 4) and postevent (cycle 5) cycles. We used mixed-effects models to estimate the age- and country-adjusted difference in change in cycle length across the groups.

RESULTS

We included 6,514 users from 110 countries representing 32,570 cycles (COVID-19 symptoms: 1,450; COVID-19 vaccination: 4,643; control: 421). The COVID-19 cohort experienced a 1.45-day adjusted increase in cycle length during cycle 4 (COVID-19) compared with their three preevent cycles (95% CI 0.86-2.04). The vaccinated group experienced a 1.14-day adjusted increase in cycle length during cycle 4 (COVID-19 vaccine) compared with their preevent average (95% CI 0.60-1.69). The control group (neither vaccine nor disease) experienced a 0.68-day decrease (95% CI -1.18 to -0.19) in a similar time period. Post hoc tests showed no significant differences in the magnitude of changes between the COVID-19 and vaccination cohorts. In both cohorts, cycle length changes disappeared in the postevent cycle.

CONCLUSION

Experiencing COVID-19 is associated with a small change in cycle length similar to COVID-19 vaccination. These changes resolve quickly within the next cycle.

Postmenopausal bleeding after COVID-19 vaccination

BACKGROUND

There is a growing literature base regarding menstrual changes following COVID-19 vaccination among premenopausal people. However, relatively little is known about uterine bleeding in postmenopausal people following COVID-19 vaccination.

OBJECTIVE

This study aimed to examine trends in incident postmenopausal bleeding diagnoses over time before and after COVID-19 vaccine introduction, and to describe cases of new-onset postmenopausal bleeding after COVID-19 vaccination.

STUDY DESIGN

For postmenopausal bleeding incidence calculations, monthly population-level cohorts consisted of female Kaiser Permanente Northwest members aged ≥45 years. Those diagnosed with incident postmenopausal bleeding in the electronic medical record were included in monthly numerators. Members with preexisting postmenopausal bleeding or abnormal uterine bleeding, or who were at increased risk of bleeding due to other health conditions, were excluded from monthly calculations. We used segmented regression analysis to estimate changes in the incidence of postmenopausal bleeding diagnoses from 2018 through 2021 in Kaiser Permanente Northwest members meeting the inclusion criteria, stratified by COVID-19 vaccination status in 2021. In addition, we identified all members with ≥1 COVID-19 vaccination between December 14, 2020 and August 14, 2021, who had an incident postmenopausal bleeding diagnosis within 60 days of vaccination. COVID-19 vaccination, diagnostic procedures, and presumed bleeding etiology were assessed through chart review and described. A temporal scan statistic was run on all cases without clear bleeding etiology.

RESULTS

In a population of 75,530 to 82,693 individuals per month, there was no statistically significant difference in the rate of incident postmenopausal bleeding diagnoses before and after COVID-19 vaccine introduction (P=.59). A total of 104 individuals had incident postmenopausal bleeding diagnosed within 60 days following COVID-19 vaccination; 76% of cases (79/104) were confirmed as postvaccination postmenopausal bleeding after chart review. Median time from vaccination to bleeding onset was 21 days (range: 2-54 days). Among the 56 postmenopausal bleeding cases with a provider-attributed etiology, the common causes of bleeding were uterine or cervical lesions (50% [28/56]), hormone replacement therapy (13% [7/56]), and proliferative endometrium (13% [7/56]). Among the 23 cases without a clear etiology, there was no statistically significant clustering of postmenopausal bleeding onset following vaccination.

CONCLUSION

Within this integrated health system, introduction of COVID-19 vaccines was not associated with an increase in incident postmenopausal bleeding diagnoses. Diagnosis of postmenopausal bleeding in the 60 days following receipt of a COVID-19 vaccination was rare.

Disturbances of menstrual cycle after immunization against SARS-CoV-2 and their risk factors: Cross-sectional clinical study

OBJECTIVE

Abnormalities of the menstrual cycle were reported after infection with SARS-CoV-2 and vaccination against it, but the available data are very heterogeneous, do not reflect intermenstrual variations or regional differences, and their risk factors are missing.

METHODS

We performed a survey-based study among 6383 employees and students of Ulm University Hospital in Germany between March 1 and 31, 2021. Attributes of menstrual cycles such as cycle length (CL), menses duration (MD), and bleeding volume (BV) were reported as categorical variables before and after immunization against SARS-CoV-2 (first, second, third vaccination or infection). Additionally, the potential risk factors for cycle changes were evaluated and all participants reported the subjective perception of changes, their duration, and time of occurrence.

RESULTS

The final analysis included 1726 participants. CL and BV significantly changed after vaccination, but not MD. The subjective perception showed only slight levels of agreement with the objective changes, with the highest Cohen's kappa for CL. The risk factors for the variations in CL were previous cycle irregularities, and risk factors for the changes in BV were age and body mass index. The combination of vaccines (homogenous or heterogeneous) and different types of immunization (infection and vaccination) had no significant effect on cycle irregularities.

CONCLUSION

In summary, immunization against SARS-CoV-2 causes changes in the characteristics of the menstrual cycle, which are mostly temporary. The individual risk factors, but not the type of immunization, can affect the mentioned changes.

Unexpected vaginal bleeding and COVID-19 vaccination in nonmenstruating women

The association between coronavirus disease 2019 (COVID-19) vaccination and vaginal bleeding among nonmenstruating women is not well studied. The Norwegian Institute of Public Health followed several cohorts throughout the pandemic and early performed a systematic data collection of self-reported unexpected vaginal bleeding in nonmenstruating women. Among 7725 postmenopausal women, 7148 perimenopausal women, and 7052 premenopausal women, 3.3, 14.1, and 13.1% experienced unexpected vaginal bleeding during a period of 8 to 9 months, respectively. In postmenopausal women, the risk of unexpected vaginal bleeding (i.e., postmenopausal bleeding) in the 4 weeks after COVID-19 vaccination was increased two- to threefold, compared to a prevaccination period. The corresponding risk of unexpected vaginal bleeding after vaccination was increased three- to fivefold in both nonmenstruating peri- and premenopausal women. In the premenopausal women, Spikevax was associated with at 32% increased risk as compared to Comirnaty. Our results must be confirmed in future studies.

Prevalence of and risk factors for self-reported menstrual changes following COVID-19 vaccination: a Danish cohort study

STUDY QUESTION

Are there some characteristics that render individuals more susceptible to report menstrual changes following the Coronavirus disease 2019 (COVID-19) vaccination?

SUMMARY ANSWER

We found that 30% of menstruating women reported menstrual changes following COVID-19 vaccination and several potential risk factors including stress, vaccine concerns, severe COVID-19 infection, and immediate vaccine symptoms were associated with these reports.

WHAT IS KNOWN ALREADY

Studies suggest that COVID-19 vaccination might temporarily prolong menstrual cycle length by less than 1 day. Specific characteristics may trigger menstrual changes in temporal relation to the vaccination simply by chance or render women more vigilant to potential menstrual changes after being vaccinated. However, research investigating potential risk factors for reporting menstrual changes following COVID-19 vaccination is limited.

STUDY DESIGN, SIZE, DURATION

A population-based Danish cohort study. Data were collected from May 2021 to December 2021 as a part of the BiCoVac Cohort with the aim of examining non-specific effects following COVID-19 vaccination. The main study population included 13 648 menstruating women aged 16-65 years who completed all surveys, received their first dose of a COVID-19 vaccine during the data collection period, and completed questions related to their menstrual cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Potential risk factors included 14 biological, physical, or psychological measures. Information on most potential risk factors was self-reported and collected before the participants' first COVID-19 vaccination. Information about any menstrual change following COVID-19 vaccination was self-reported at the end of the data collection period. Logistic regression analyses were used to estimate crude and adjusted odds ratios (ORs) with 95% CIs for the association between each potential risk factor and reporting menstrual changes following COVID-19 vaccination.

MAIN RESULTS AND THE ROLE OF CHANCE

Any menstrual change following COVID-19 vaccination was reported by 30% of menstruating women. Most of the potential risk factors were associated with reports of menstrual changes following COVID-19 vaccination. In particular, higher odds were found among women who reported ≥5 immediate vaccine symptoms; OR 1.67 [1.50-1.86], had had a prior severe COVID-19 infection; OR 2.17 [1.40-3.35], had a high-stress level at baseline; OR 1.67 [1.32-2.10], or were concerned about COVID-19 vaccines prior to vaccination; OR 1.92 [1.50-2.45]. Lower odds were found among women with regular menstrual cycles using hormonal contraception; OR 0.71 [0.65-0.78].

LIMITATIONS, REASONS FOR CAUTION

We were unable to address the causal effect of COVID-19 vaccination on the reported menstrual changes, as information about menstrual changes was not available among non-vaccinated women.

WIDER IMPLICATIONS OF THE FINDINGS

The study identified several potential risk factors for reporting menstrual changes following COVID-19 vaccination. Further studies are needed to establish causal associations and the clinical impact of self-reported menstrual changes.

STUDY FUNDING/COMPETING INTEREST(S)

The BiCoVac data collection was funded by TrygFonden (id-number: 153678). No competing interests are declared.

TRIAL REGISTRATION NUMBER

N/A.

Why we must fight ignorance about COVID-19 vaccines and menstrual cycles

The COVID-19 pandemic has revealed a critical gap in female health science, fueling anxiety, polarized views, and vaccine hesitancy. Although menstrual cycles feel like a niche topic for some, efforts to augment knowledge on the 'fifth vital sign' experienced by more than 300 million people on any given day worldwide are crucial to promote gender equity in health.

Heavy bleeding and other menstrual disturbances in young women after COVID-19 vaccination

BACKGROUND

Many signals of menstrual disturbances as possible side effects of vaccination against COVID-19 have been reported. Our objective was to compare the risk of menstrual disturbances before and after vaccination among women aged 18-30 years in Oslo, Norway.

METHODS

We used electronic questionnaires to collect reports of menstrual disturbances from 3972 women aged 18-30 years, participating in the population-based Norwegian Young Adult Cohort. We examined the occurrence of menstrual disturbances (heavier bleeding than usual, prolonged bleeding, shorter interval between menstruations, longer interval between menstruations, spot bleedings, stronger pain during menstruation, period pain without bleeding) before and after the first and second dose of COVID-19 vaccine. Relative risks (RR) according to vaccination were estimated using a self-controlled case-series design. We performed additional analyses stratified by vaccine brand, contraception/hormone use, and presence of gynecological condition(s).

RESULTS

The prevalence of any menstrual disturbance was 36.7 % in the last menstrual cycle prior the first vaccine dose. The RR for heavier bleeding than usual was 1.90 (95 % CI: 1.69-2.13) after the first vaccine dose and 1.84 (95 % CI 1.66-2.03) after the second dose. Increased risks of prolonged bleeding, shorter interval between menstruations, and stronger pain during menstruation were also observed after both doses. The RRs did not differ with vaccine brand, contraception/hormone use, or presence of gynecological condition(s) for any of the menstrual disturbances.

CONCLUSION

Menstrual disturbances were common regardless of vaccination. We found increased risk of menstrual disturbances after vaccination, particularly for heavier bleeding than usual, prolonged bleeding, shorter interval between menstruations, and stronger period pain. In the future, menstrual characteristics should be included in vaccine trials.

The Impact of COVID-19 on Menstrual Cycle in Women

BACKGROUND

The COVID-19 pandemic has become the largest and most diverse to threaten the health of humanity since the 1918 influenza pandemic.

METHODS

This study involved 113 women who had suffered from COVID-19. The study was conducted as interviews with each woman during visits to a clinic prior to the start of their post-COVID-19 physiotherapy treatment cycle. The aim of this study was to assess the prevalence of changes in the women's monthly cycles related to COVID-19, as well as to analyse correlations between dependent variables relating to changes in the monthly cycle and independent variables relating to other factors, such as age, weight, number and type of vaccinations, and time since illness. Additionally, the study assesses correlations between the monthly cycle and COVID-19 symptoms persisting after the illness (long COVID).

RESULTS

Women who reported more symptoms of COVID-19 were more likely to report changes in their menstrual cycle occurring after the SARS-CoV-2 infection, compared with women whose disease course was mild. Women who declared that COVID-19 affected their monthly cycles most often indicated increases in abdominal, lower abdominal, and joint and muscle pain, as well as in the severity of headaches during monthly bleeding. A small percentage of women indicated that their monthly cycles were longer and their regularity disrupted.

CONCLUSIONS

This study shows that the more COVID-19 symptoms a woman had, the more often there were noted changes in monthly cycle. The same relationship was also found for persistent long COVID symptoms. The longer the time lapse since the COVID-19 infection, the less frequently changes in the monthly cycle were recorded.

SARS-CoV-2 infection and female reproductive health: A narrative review

The COVID-19 pandemic has had a profound global impact, affecting people's physical and mental health, and their social and economic circumstances. Mitigation measures have disproportionately affected women. Studies have reported menstrual cycle and psychological disturbance associated with the pandemic. Pregnancy is a risk factor for severe COVID-19 disease. Reports have also demonstrated associations between COVID-19 infection, vaccination and Long COVID syndrome and reproductive health disturbance. However, studies are limited and there may be significant geographical variation. Also there is bias amongst published studies, and menstrual cycle data was not included in COVID-19 and vaccine trials. Longitudinal population based studies are required. In this review we discuss existing data, along with recommendations for further research required in this area. We also discuss a pragmatic approach to women presenting with reproductive health disturbance in the era of the pandemic, encompassing a multi-system assessment of psychological, reproductive health and lifestyle.

COVID-19 vaccination and menstrual cycle characteristics: A prospective cohort study

We prospectively examined the association between COVID-19 vaccination and menstrual cycle characteristics in an internet-based prospective cohort study. We included a sample of 1,137 participants who enrolled in Pregnancy Study Online (PRESTO), a preconception cohort study of couples trying to conceive, during January 2021-August 2022. Eligible participants were aged 21-45 years, United States or Canadian residents, and trying to conceive without fertility treatment. At baseline and every 8 weeks for up to 12 months, participants completed questionnaires on which they provided information on COVID-19 vaccination and menstrual cycle characteristics, including cycle regularity, cycle length, bleed length, heaviness of bleed, and menstrual pain. We fit generalized estimating equation (GEE) models with a log link function and Poisson distribution to estimate the adjusted risk ratio (RR) for irregular cycles associated with COVID-19 vaccination. We used linear regression with GEE to estimate adjusted mean differences in menstrual cycle length associated with COVID-19 vaccination. We adjusted for sociodemographic, lifestyle, medical and reproductive factors. Participants had 1.1 day longer menstrual cycles after receiving the first dose of COVID-19 vaccine (95 % CI: 0.4, 1.9) and 1.3 day longer cycles after receiving the second dose (95 % CI: 0.2, 2.5). Associations were attenuated at the second cycle post-vaccination. We did not observe strong associations between COVID-19 vaccination and cycle regularity, bleed length, heaviness of bleed, or menstrual pain. In conclusion, COVID-19 vaccination was associated with a ∼1 day temporary increase in menstrual cycle length, but was not appreciably associated with other menstrual cycle characteristics.

Menstrual cycle length variation by demographic characteristics from the Apple Women's Health Study

Menstrual characteristics are important signs of women's health. Here we examine the variation of menstrual cycle length by age, ethnicity, and body weight using 165,668 cycles from 12,608 participants in the US using mobile menstrual tracking apps. After adjusting for all covariates, mean menstrual cycle length is shorter with older age across all age groups until age 50 and then became longer for those age 50 and older. Menstrual cycles are on average 1.6 (95%CI: 1.2, 2.0) days longer for Asian and 0.7 (95%CI: 0.4, 1.0) days longer for Hispanic participants compared to white non-Hispanic participants. Participants with BMI ≥ 40 kg/m² have 1.5 (95%CI: 1.2, 1.8) days longer cycles compared to those with BMI between 18.5 and 25 kg/m². Cycle variability is the lowest among participants aged 35-39 but are considerably higher by 46% (95%CI: 43%, 48%) and 45% (95%CI: 41%, 49%) among those aged under 20 and between 45-49. Cycle variability increase by 200% (95%CI: 191%, 210%) among those aged above 50 compared to those in the 35-39 age group. Compared to white participants, those who are Asian and Hispanic have larger cycle variability. Participants with obesity also have higher cycle variability. Here we confirm previous observations of changes in menstrual cycle pattern with age across reproductive life span and report new evidence on the differences of menstrual variation by ethnicity and obesity status. Future studies should explore the underlying determinants of the variation in menstrual characteristics.

Adverse Hematological Effects of COVID-19 Vaccination and Pathomechanisms of Low Acquired Immunity in Patients with Hematological Malignancies

The SARS-CoV-2 virus and the COVID-19 pandemic have spread across the world and severely impacted patients living with hematological conditions. Immunocompromised patients experience rapidly progressing symptoms following COVID-19 infection and are at high risk of death. In efforts to protect the vulnerable population, vaccination efforts have increased exponentially in the past 2 years. Although COVID-19 vaccination is safe and effective, mild to moderate side effects such as headache, fatigue, and soreness at the injection site have been reported. In addition, there are reports of rare side effects, including anaphylaxis, thrombosis with thrombocytopenia syndrome, Guillain-Barré Syndrome, myocarditis, and pericarditis after vaccination. Further, hematological abnormalities and a very low and transient response in patients with hematological conditions after vaccination raise concerns. The objective of this review is to first briefly discuss the hematological adverse effects associated with COVID-19 infection in general populations followed by critically analyzing the side effects and pathomechanisms of COVID-19 vaccination in immunocompromised patients with hematological and solid malignancies. We reviewed the published literature, with a focus on hematological abnormalities associated with COVID-19 infection followed by the hematological side effects of COVID-19 vaccination, and the mechanisms by which complications can occur. We extend this discussion to include the viability of vaccination efforts within immune-compromised patients. The primary aim is to provide clinicians with critical hematologic information on COVID-19 vaccination so that they can make informed decisions on how to protect their at-risk patients. The secondary goal is to clarify the adverse hematological effects associated with infection and vaccination within the general population to support continued vaccination within this group. There is a clear need to protect patients with hematological conditions from infection and modulate vaccine programs and procedures for these patients.

COVID-Related Distress Is Associated with Increased Menstrual Pain and Symptoms in Adult Women

The COVID-19 pandemic resulted in heightened stress for many individuals, with women reporting more stress than men. Although a large body of evidence has demonstrated that stress, in general, can impact the menstrual cycle, it is not yet clear if COVID-specific stress would impact women's menstrual health. The current study explored the relationship between COVID-related stress and distress and menstrual variables (menstrual pain, number and severity of menstrual symptoms, and menstrual pain interference) in a sample of reproductive-age adult women. Seven-hundred fifteen women completed the initial survey and were re-contacted to complete the same survey three months later. Of those recontacted, 223 completed the follow-up survey. Results indicated that COVID-related stress and distress was associated with higher levels of menstrual pain, more frequent and more severe menstrual symptoms, and greater menstrual pain interference, even after accounting for age, hormonal use, bodily pain, and pain catastrophizing. Our findings suggest that women experience unique vulnerabilities that directly impact their health and functioning, and both research and clinical care should address these symptoms through careful assessment and treatment of menstrual pain and symptoms, particularly during and after periods of high stress and distress.