Introduction. Low birth weight is an important indicator of the health of babies. A low birth weight is a leading health problem and a major reason for death in newborns. This study targeted to assess the relationship between maternal and infant factors and low birth weight in Iran through a systematic review and meta-analysis.

Materials and Methods. This paper was a systematic review and meta-analysis of the relationship between maternal/ infant factors and low birth weight based on the published research papers conducted in Iran. To achieve this goal, two trained researchers independently elicited all the relevant articles by using the appropriate keywords and their combinations in SID, Madlib, Iranmedex, Irandoc, Google Scholar, Pubmed, ISI, Scopus and Magiran databases. The results of the study were combined with SPSS 20 and STATA software.

Results. In the initial stage, 25 more relevant articles out of 46 papers were selected. The gestational age with less than 37 weeks and prenatal care had the most (CI: 27- 14. 53, OR: 19.81) and the least (CI: 1.86, OR: 1.5) effect on the low birth weight in newborns, respectively.

Conclusion. This study showed that there is a significant relationship between the low birth weight and multiple births, pre-eclampsia, maternal weight gaining during pregnancy, baby’s gender, and pregnancy age. Hence, controlling the factors above in mothers during pregnancy by the health authorities could lead to the birth of infants with a healthy weight and consequently the number of infants with low birth weight will decrease.