en بهداشت Health تحقیقی Original article <strong>Background:</strong> Sperm preparation is a time-consuming process that makes a contribution to oxidative stress induction in assisted reproductive techniques.<br> <strong>Objective:</strong> This study aimed to evaluate the effect of L-carnitine on sperm parameters during semen preparation at different time intervals.<br> <strong>Materials and Methods<span dir="RTL">:</span></strong> In this in vitro study, the semen samples of 50 asthenoteratozoospermic men were divided into the control and the L-carnitine groups (incubated with 0.5 mg/mL L-carnitine) (n=25/each). Total motility, progressive motility, sperm membrane integrity (by Hypo-osmotic swelling test), and lipid peroxidation (by Malondialdehyde level) were assessed in each group after 2, 4, and 6 hours. Afterward, samples were analyzed by the World Health Organization (2010) criteria.<span dir="RTL"></span><br> <strong>Result:</strong> The results showed that in the control group total and progressive motility, and membrane integrity of the sperm were significantly decreased after 2 hr (P= 0.028, p= 0.019, and p= 0.025, respectively), while Malondialdehyde levels increased significantly after 4 hr (P= 0.018). Sperm parameters in the L-carnitine group increased significantly after 2 hr (P= 0.002), while Malondialdehyde levels decreased significantly compared to the control group in 6 hr (P < 0.001 vs. P =0.045).<br> <strong>Conclusion:</strong> Based on these results, L-carnitine can manage to conserve motility and sperm membrane integrity of sperm from the hazardous impact of oxidative stress and lipid peroxidation during sperm preparation. L-carnitine,Asthenoteratozoospermia,Membrane integrity,Sperm parameter 19 23 http://goums.ac.ir/jorjanijournal/browse.php?a_code=A-10-794-6&slc_lang=en&sid=1 Samira Naderi Noreini samiranaderi1867@gmail.com 100319475328460010841 0000000303752614 No Rastak Infertility Center, Arak, Iran Roya Ahmadi Nia Tabesh niyatabesh90@gmail.com 100319475328460010842 100319475328460010842 No Department of Midwifery, Tuyserkan Branch, Islamic Azad University, Tuyserkan, Iran Mahdi Malmir m.malmir66@hotmail.com 100319475328460010843 000000017915849X No Department of Midwifery, Tuyserkan Branch, Islamic Azad University, Tuyserkan, Iran Ali Asghar Ghafarizade Ghafarizade@acecr.ac.ir 100319475328460010844 0000000309586303 Yes Academic Center for Education, Culture and Research, Arak, Iran