Materials and Methods: This systematic review and meta-analysis was performed based on the studies conducted in Iran. An advanced search was carried out in seven databases (Iranmedex, Magiran, SID, Irandoc, PubMed, Google Scholar, and Scopus) for relevant articles published during 2000-2016 using the keywords ?social determinants of health?, ?preterm birth?, and their Persian equivalents and MeSH terms. All the articles were screened by 2 of the researchers in 3 steps. After looking for relevant articles based on the reference list, quality assessment was performed using a STROBE checklist. After extracting the required data, they were combined using a random model and the heterogeneity of the studies was evaluated using the I2 index and the data were analyzed in STATA-11.

Results: A total of 16 studies were included in the analysis of the relationship between the intermediate determinants of health and preterm birth; however, only 6 truly investigated the relationship between structural determinants and preterm birth. The overall odds ratios for the relationship of the structural and intermediate social determinants of health with preterm birth were estimated as 1.43 (0.84%-2.41%: 95% CI) and 2.17 (1.75%-2.68%: 95% CI). The results showed that preterm birth was more common in women with anxiety, depression, unwanted pregnancies, poor health behaviors (smoking, the use of alcohol and drugs), inadequate prenatal care, and those who were abused and exposed to secondhand tobacco smoke (P<0.05).

Conclusions: The results of the reviewed studies suggest that preterm birth is a common problem associated with several social determinants of health. Life skills, self-care training, and increased prenatal care are therefore recommended to reduce preterm birth, especially in high-risk pregnant women.