New Delhi, March 5 : Covid-19 mRNA vaccines do not affect the ovarian response or pregnancy rates in IVF (In-vitro fertilisation) treatment, according to a study. A team of researchers from the Tel Aviv University in Israel found that in patients undergoing IVF treatments, ovarian response and pregnancy rates were similar with those that were vaccinated with the mRNA Covid-19 vaccine prior to IVF treatment, as compared to unvaccinated women. The study published in the peer-reviewed medical journal 'Fertility and Sterility' included a total of 400 patients, 200 vaccinated women and 200 age-matched unvaccinated women, undergoing IVF during January-April 2021. The results showed no effect of Covid-19 mRNA vaccine on oocyte yield during hormonal stimulation or on pregnancy rates during IVF treatments. The study did not support concerns that the vaccine might affect fertility treatment outcomes were not supported, said researchers. "The theoretical concept of the supposed similarity between the SARS-CoV-2 spike protein and the syncytin protein that is speculated to take part in the fertilisation process and the formation of the placenta, has led to the assumption that the vaccine might induce an immune response which would affect implantation and pregnancy," said researchers, including Alon Kedem from the varsity's Shamir Medical Centre, in the study. "Our results demonstrate similar oocyte yields and fertilisation rates among vaccinated and unvaccinated women," Kedem added. The researchers said taking into account the potential harm of the infection itself on fertility, the already proven worse pregnancy outcomes among pregnant women with Covid-19 infection, and the higher risk of infection among unvaccinated pregnant women, it seems reasonable to reduce infection risk through vaccination. "We recommend considering Covid-19 vaccination prior to commencing IVF treatments in order to reduce the risk of SARS-CoV-2 infection during pregnancy," Kedem said. Preliminary reports on vaccine safety in pregnant women found similar miscarriage rates among vaccinated women as compared to historical data from the literature. However, the results of this study "strengthen the notion that it is unlikely that the vaccine would generate a response that might interfere with placentation," researchers said. Yet further studies are needed to evaluate the safety of the vaccine beyond the eighth week of pregnancy, the team said. /IANS