evidence: A 2021 report by NewsGuard, an online service that rates the reliability of news and information websites, identified several false claims related to COVID-19 vaccines and fertility and reproduction. In addition to the syncytin-1 myth, the vaccines were falsely claimed to cause infertility in 97% of women; to increase miscarriage risks; and, in males, to negatively affect the testicles, the prostate, and testosterone levels. [...] In October 2021, almost a third of 1519 US adults in a nationally representative survey by KFF, formerly the Kaiser Family Foundation, reported that they heard that COVID-19 vaccines caused infertility and either believed the myth was true or weren’t sure. About a third of pregnant adults in the US remained unvaccinated as of early February 2022, according to the Centers for Disease Control and Prevention (CDC) COVID Data Tracker’s weekly statistics. [...] Lately, patients frequently tell her they’ve heard that COVID-19 vaccines cause significant and permanent menstrual cycle changes that can lead to fertility problems. Misinformation about menstrual changes is being used to "add new fuel to the claim that COVID vaccines affect fertility," Gregory said. "It can be used to bolster the older myths."