Objectives: Breastfeeding during pregnancy has unintended repercussions that have yet to be determined. Previous research employed various approaches and reached varied outcomes, with some emphasizing on advantages and others focusing on hazards. With this study we aim at shedding light on the effects of breastfeeding during pregnancy on the outcome of pregnancy and the risk of miscarriage. Materials and methods: We conducted a systematic review of relevant papers which have been published in English between 2014 and 2022 by using the PubMed, Scopus and Google Scholar search engines. Databases identified 257 records, which were checked for their relatedness to the topic (title and abstract), and compliance with the selection criteria. Only 10 records met all requirements and were included in the present review. Results:The results revealed that breastfeeding during pregnancy appeared to be unrelated to pregnancy outcome and miscarriage risk, notwithstanding the need for caution in women at risk of preterm birth and high-risk pregnancies. Conclusion:All studies recognized the high nutritional requirements of lactating pregnant women as well as the importance of proper nutrition for a safe breastfeeding for both the mother and child (children). Further research, with larger samples and adequate methodology, is expected to lead to safer conclusions for breastfeeding during pregnancy.