J Compr Ped. 2017 August; 8(3):e12361. Published online 2017 August 31. doi: 10.5812/compreped.12361. Research Article The Association Between Prepregnancy Body Mass Index and Breastfeeding Duration in Iranian Women Afsaneh Tehranian, 1,* Ladan Hosseini, 2 Shahin Nariman, 3 Bita Eslami, 4 Hadith Rastad, 5 and Faezeh Aghajani 6 1 Department of Obstetrics and Gynecology, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran 2 Research Development Center, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran 3 Department of Pediatrics and Neonatology, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran 4 Breast Disease Research Center (BDRC), Tehran University of Medical Sciences, Tehran, Iran 5 Public Health School, Tehran University of Medical Sciences, Tehran, Iran 6 Medical School, Tehran University of Medical Sciences, Tehran, Iran * Corresponding author: Afsaneh Tehranian, Department of Obstetrics and Gynecology, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran. Tell: +98-2177719922, E-mail: afsanehtehranian@yahoo.com Received 2017 May 01; Accepted 2017 July 25. Abstract Background: The World Health Organization has recommended exclusive breastfeeding for 6 months. Breastfeeding success may be influenced by different factors. Objectives: The aim of this study was to determine the association between prepregnancy body mass index (BMI) and breastfeeding duration in Iranian mothers. Methods: This prospective cohort study was conducted at Arash Women’s Hospital in Tehran, Iran. The analysis included 593 women, followed from pregnancy until 6 months postpartum. A logistic regression model was used to determine the association between prepregnancy BMI and exclusive breastfeeding duration and initiation. Results: Women with prepregnancy BMI above 25 kg/m 2 had a higher risk (almost twice) of not initiating breastfeeding or breast- feeding for less than 1 month after delivery, compared to pregnant women who had a normal weight. In this study, adjustments were made for confounding factors, such as age, education level, mode of delivery, mother’s opinion of breastfeeding, and mother’s occupation. Conclusions: This study showed that women who had a normal prepregnancy weight were more likely to continue breastfeed- ing for 6 months, while obese and overweight women had a shorter duration of breastfeeding in comparison with normal-weight women. Keywords: Prepregnancy Body Mass Index, Breastfeeding Duration, Gestational Weight Gain 1. Background The prevalence of obesity is growing worldwide, and this condition has become a public health problem (1). Obesity is a risk factor for not only chronic diseases (2), but also maternal and prenatal complications (3). According to previous studies, the rate of hypertension, preeclamp- sia, gestational diabetes, dystocia (4, 5), cesarean section, prolonged delivery, intrauterine fetal death, and congeni- tal abnormalities (3, 6) is higher in obese mothers in com- parison with others. Numerous factors can influence the initiation of breastfeeding, such as mother’s weight, ethnicity, occupa- tion, and economic status. Additionally, a large number of studies have shown an adverse association between ma- ternal obesity and breastfeeding initiation and duration (7-10). Rasmussen indicated that risk of early breastfeed- ing cessation is approximately 14.4% among obese class III mothers versus 3.5% in normal-weight women with body mass index (BMI) above 26 kg/m 2 (11). The etiology of the association between maternal obe- sity and breastfeeding initiation and duration is unknown, although some social factors seem to influence this re- lationship (12). In Iran, Islam has suggested mothers to breastfeed their children for 2 years. 2. Objectives With this background in mind, in this study, we aimed to determine the association of prepregnancy BMI with breastfeeding initiation and duration in Iranian mothers. 3. Methods This prospective study was performed among single- ton pregnant women in the first trimester of pregnancy, Copyright © 2017, Journal of Comprehensive Pediatrics. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.