Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 18 4 2023 11 21 474 482 EN Mina Shajrizadeh Department of Parasitology, School of Medicine, Shahid Beheshty University of Medical sciences Tehran Iran Farid Tahvildar Biderouni Department of Parasitology, School of Medicine, Shahid Beheshty University of Medical sciences Tehran Iran Mohammad Reza Sohrabi Department of Social Medicine, School of Medicine, Shahid Beheshty University of Medical sciences Tehran Iran Alireza Abadi Department of Social Medicine, School of Medicine, Shahid Beheshty University of Medical sciences Tehran Iran Seyyed Javad Seyyedtabaei Department of Parasitology, School of Medicine, Shahid Beheshty University of Medical sciences Tehran Iran 2022 05 21 2023 02 27 Background: Toxoplasmosis could lead to serious outcomes during pregnancy. The aim of this study was to investigate serologic toxoplasmosis in three groups of women according to number of sexual partners. Methods: The frequency of anti-Toxoplasma IgG from 471 women (101 virgin girls, 240 married women and 130 multi partner women) were determined by ELISA method from referred participant to medical centers of Tehran, Iran in 2020. The results were analyzed by chi-square and logistic regression tests. Results: Prevalence of toxoplasmosis was significant with the number of sexual partner according to chi square test (P<0.001) and the highest one was observed in multi partners’ women (56.2%) and the lowest one in virgin girls (17.8%). ORs of virgin girls and multi partners’ women were 0.594 and 3.758 respectively, compared to married women. The effect of age on the frequency of anti-Toxoplasma IgG in married women was significant but it was not significant in multi partners’ women. In addition to IgG frequency in married women and multi partners’ women had no significant relationship with the number of children. Conclusion: Having sexual activity after marriage and having multi partner in sexual activity may possibly be a novel risk factor for toxoplasmosis infection or increasing the IgG frequency. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3629 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3629/1324