Pregnant and postpartum women with a history of bariatric surgery are at risk of micronutrient deficiencies as a result of the combination of physiologic changes related to pregnancy and iatrogenic postoperative alterations in the absorption and metabolism of crucial nutrients. This systematic review investigates micronutrient deficiencies and related adverse clinical outcomes in pregnant and postpartum women after bariatric surgery. A systematic approach involving critical appraisal was conducted independently by 2 researchers to examine deficiencies of phylloquinone, folate, iron, calcium, zinc, magnesium, iodide, copper, and vitamins A, D, and B-12 in pregnant and postpartum women after bariatric surgery, together with subsequent outcomes in the neonates. The search identified 29 relevant cases and 8 cohort studies. The quality of reporting among the case reports was weak according to the criteria based on the CARE (CAse REporting) guidelines as was that for the cohort studies based on the criteria from the Cohort Study Quality Assessment list of the Dutch Cochrane Center. The most common adverse neonatal outcomes related to maternal micronutrient deficiencies include visual complications (vitamin A), intracranial hemorrhage (phylloquinone), neurological and developmental impairment (vitamin B-12), and neural tube defects (folate). On the basis of the systematically collected information, we conclude that the evidence on micronutrient deficiencies in pregnant and postpartum women after bariatric surgery and subsequent adverse neonatal outcomes remains weak and inconclusive