All the identified articles were reviewed to find and avoid possible duplication and then arranged for further
survey. By analyzing the titles of the articles, the ones whose design differed from inclusion criteria (metabolic
syndrome in pregnancy, adverse perinatal outcome) were excluded. Summaries of the articles were read and selected
and we excluded those which did not mention the features of metabolic syndrome in pregnancy and its
adverse perinatal outcomes. The complete text of selected articles were retrieved and reviewed independently.
After data extraction, a new review of articles was made as a means to ensure that the data of the selected articles
were included only once in the analysis, which resulted in only 27 remaining articles taking part with this
review.