Background: The prevalence of mental health issues among mothers going through the perinatal phase is increasing day by day. Many factors can contribute to maternal mental health issues. These factors may be internal like hormonal changes or external like stressful environments. In this paper, we aimed to systematically review the previous studies to analyze the effects of various factors on maternal mental health. Methodology: In this regard, we have reviewed several studies that analyze the influence of various factors on maternal mental health during pregnancy. These studies were taken from the following search engines: Google Scholar, PubMed, and Science Direct. All the studies were originally written and published in the English language. All the studies discuss maternal mental health during pregnancy without analyzing the impact of any other disease. Results: It has been found that various factors affect the mental health of mothers during pregnancy. The major factors that are found to be affecting mothers’ mental health are hormonal changes, advanced-age pregnancy, stressful occupations, and early-age pregnancy. Conclusion: In this systematic review, we aimed to identify various factors affecting the mental well-being of mothers during pregnancy. We indicated that factors such as hormonal changes, advanced-age pregnancy, stressful occupations, and early-age pregnancy are the potential variables that affect the maternal mental health. in this paper we discussed these variables in detail and suggested possible solutions to these issues