Introduction Parturition process consists of three stages: 1) from parturition pain onset to complete cervical dilatation; 2) from complete cervical dilatation to child delivery; and 3) from complete fetus delivery to placental delivery. Retained placenta means that the placenta is remained in the mother’s uterine for a certain period after fetus delivery. This period is reported to be between 30-60 minutes in different countries (1,2). The prevalence of retained placenta is different between various countries and it has been 0.01% to 6.3% in different studies (3). Parturition is a prevalent complication caused by a long third stage bleeding. It is a common cause of death in the developing and even developed countries (4). Risk factors for the retained placenta can be gestational age (especially less than 26 weeks), preeclampsia, abortion history, old age, high polarity, use of parturition medicines such as oxytocin, being of non-Asian race and also other factors such as small placenta, too much bleeding and vaginal damage history (5). Furthermore, studies have revealed that taking intra-vein ergometrine can be a risk factor for the retained placenta (5-7). Likewise, taking methyl ergometrine rather than oxytocin is more associated with retained placenta (8). Many treatments have been proposed for the retained placenta, however, there are a few reports on using prostaglandins and umbilical vein injection of oxytocin (9). Moreover, different administration methods of oxytocin and misoprostol (oral, vaginal, or intravenous injection) have had different results (10,11). We undertook this investigation because this treatment can prevent dangerous consequences for a mother’s life. Few studies have compared the effects of umbilical vein injection of oxytocin and misoprostol. Therefore, this study compared the umbilical vein injection of misoprostol and oxytocin to manage retained placenta in the women who had referred to Moheb-Yass and Shariati hospitals in Tehran and Bandar Abbas cities, Iran. Materials and Methods This randomized clinical trial was done on 44 women suffering from a long third stage parturition (retained placenta after 30 minutes) who had referred to the hospital between 2012 and 2015. They were randomly divided into 2 groups: oxytocin and misoprostol groups. The inclusion criteria were: 1) successful first and second parturition stages and 2) having a retained placenta 30 minutes after fetus delivery. The exclusion criteria were: 1) instability Abstract Objectives: Retained placenta in the third stage of labor causes complications that may threaten a mother’s life. In this clinical trial, we compared umbilical vein injection of misoprostol and oxytocin for managing the retained placenta in the women who had referred to Moheb-Yass and Shariati hospitals in Tehran and Bandar Abbas cities, Iran. Materials and Methods: Between 2012 and 2015, 44 women with a long third stage of labor (retained placenta for more than 30 minutes) were chosen for this study. They were randomly divided into 2 groups: oxytocin and misoprostol groups (22 women in each group). In oxytocin group, oxytocin was injected into the umbilical vein with 50-unit concentration in 30 mL of normal saline. In misoprostol group, 800 μg of misoprostol was injected into the umbilical vein in 30 mL of normal saline. Placenta delivery time, bleeding after parturition, and hemoglobin drop were compared between the 2 groups. Results: There was no significant difference between umbilical vein injection of misoprostol or oxytocin regarding spontaneous placental delivery in the mothers younger than 30 years old. Totally, spontaneous placental delivery was significantly more in the misoprostol group. This was magnified among women who were pregnant for more than 30 weeks. Conclusions: Umbilical vein injection of misoprostol is more effective than that of oxytocin in managing the retained placenta in the third stage of labor. Keywords: Retained placenta, Misoprostol, Oxytocin, Umbilical vein Umbilical Vein Injection of Misoprostol Versus Oxytocin for Managing Retained Placenta After Parturition: A Randomized Clinical Trial Aida Najafian 1 , Marzieh Ghasemi 2 , Neda Hajiha-Esfahani 3* Open Access Original Article International Journal of Women’s Health and Reproduction Sciences Vol. 6, No. 3, July 2018, 297–301 http://www.ijwhr.net doi 10.15296/ijwhr.2018.49 ISSN 2330- 4456 Received 13 January 2017, Accepted 20 October 2017, Available online 11 November 2017 1 Department of Endocrinology and Infertility, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2 Department of Obstetrics and Gynecology, Faculty of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran. 3 Department of Obstetrics and Gynecology, Moheb-Yass Hospital, Tehran University of Medical Sciences, Tehran, Iran. *Corresponding Author: Neda Hajiha-Esfahani, Tel: +982122226577, Fax: +982188008810, Email: neda_hajiha@yahoo.com