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.

Mortality, Morbidity and Related Outcomes Following Perioperative Blood Transfusion in Patients with Major Orthopaedic Surgery: A Systematic Review.

BACKGROUND: Benefits and risks of liberal and restrictive transfusion regimens are under on-going controversial discussion. This systematic review aimed at assessing both regimens in terms of pre-defined outcomes with special focus on patients undergoing major orthopaedic surgery. METHODS: We performed a literature search for mortality, morbidity and related outcomes following peri-operative blood transfusion in patients with major orthopaedic surgery in electronic databases. Combined outcome measure estimates were calculated within the scope of meta-analyses including randomised clinical trials comparing restrictive versus liberal blood transfusion regimens (e.g. MH risk ratio, Peto odds ratio). RESULTS: A total of 880 publications were identified 15 of which were finally included (8 randomised clinical trials (RCTs) with 3,693 patients and 6 observational studies with 4,244,112 patients). Regarding RCTs, no significant differences were detected between the transfusion regimes for all primary outcomes (30-day mortality, thromboembolic events, stroke/transitory ischaemic attack, myocardial infarction, wound infection and pneumonia) and a secondary outcome (length of hospital stay), whereas there was a significantly reduced risk of receiving at least one red blood concentrate under a restrictive regimen. CONCLUSION: The results of this systematic review do not suggest an increased risk associated with either a restrictive or a liberal transfusion regimen in patients undergoing major orthopaedic surgery.