The effect of twin birth on neonatal and infant mortality rates: A systematic review

Background: Twin birth may account for a higher incidence rates of infants and neonates. To investigate the potential relationship between twin birth and infant and neonatal mortality rates, a systematic review was conducted.Methodology: To gather the evidence for the relationship between twin birth and its potential effect on mortality during infancy and neonatal periods, a systematic review was conducted. The most important used databases were PubMed, Google scholar, Web of Science, Scopus, ProQuest, Cochrane and Springer. Then, the databases were searched by appropriate keywords. After reviewing and evaluating the collected studies, trends in the different countries were compared. Results: Totally, 13790 related studies were found, of which 128 studies were selected in the first step. The studies not related to the subject, repetitive studies, based on inclusion and exclusion criteria by reviewing the abstract and, in some cases with the full article, were excluded from the search in the second step. Finally, seven studies entered in the last step. Conclusion: This study showed that the mortality of twins could be higher than non-twins, especially among boys.