Tehran University of Medical Sciences Traditional and Integrative Medicine 2476-5104 5 2 2020 06 27 70 85 Kosar Raoufinejad Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran Kheirollah Gholami Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran AND Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran Mohammadreza Javadi Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran Mehdi Rajabi Department of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy, Islamic Azad University of Medical Sciences, Tehran, Iran AND Department of Clinical Pharmacy, University Hospitals of North Midlands, Stoke-on-Trent, Staffordshire, UK Hassan Torkamandi Department of Pharmaceutical Care, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Ashraf Moeini Department of Gynecology and Obstetrics, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran Niayesh Mohebbi Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran AND Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran 2020 05 01 2020 06 06 This study aimed to investigate the herbal medicines use prevalence and adverse drug reactions (ADRs) during pregnancy as well as the probable effects on newborn outcomes. Postpartum women with a live singleton infant were eligible if declared consent before discharge. Data was collected retrospectively by face-to-face interviews. Generally, 400 pairs of mother/infant were recruited. At least one herbal medicine was used by 325/400 (81.3%) women. Peppermint, frankincense, flixweed, olive oil, and cinnamon were the most common herbs. Overall, 26 ADRs were reported by 19/325 (5.8%) women. Gastrointestinal complaints were the most frequent herbal ADRs (18/26, 69.2%). Gestational age, Apgar scores, birthweight, complications, and malformations of newborns were similar between groups. In conclusion, herbal medicines were highly used by pregnant women, while they did not affect newborn outcomes either positively or adversely. Despite low frequency rate of herbal ADRs during pregnancy, their safety, efficacy, interactions, and potential risks need further studies. https://jtim.tums.ac.ir/index.php/jtim/article/view/227