INTRODUCTION:: Bariatric surgery (BS) has been shown to improve pregnancy outcomes in obese patients. Studies suggest increased incidence of small for gestational age (SGA) neonates in women with BS, without clear explanation. The objective of this study is to investigate the incidence of SGA in neonates after BS in relationship to the type of BS, time interval from surgery to delivery (TI), and maternal micronutrient deficiency. METHODS:: This is a retrospective chart review of women with history of BS who delivered between 2013 and 2017 at our institution. The mothers with BS (N = 70) were compared with a cohort of mothers without BS (NBS) (N = 70) with similar body mass index. Type of bariatric surgery (malabsorption versus restrictive), micronutrient deficiencies (use of supplemental iron, folate, B12, and blood transfusions), and TI were analyzed for each cohort. Multiple gestations were excluded. Institutional Review Board approval was obtained. RESULTS:: Both groups had similar maternal characteristics and perinatal and neonatal complications (p > 0.05). SGA was increased in patients with BS (14.4%) compared with NBS (2.9%). Women with restrictive BS (N=42) had an increased incidence (p = 0.04) of SGA compared to malabsorptive BS (N=27). SGA was increased in patients with TI less than 4 years (p = 0.02). There was no impact of anemia (p = 0.89) or obesity class (p = 0.92) on neonatal birthweight. CONCLUSION:: Restrictive bariatric surgery and time interval less than 4 years is associated with increased incidence of SGA in patients with history of bariatric surgery.