A Meta-Analysis of Prenatal and Maternal Risk Factors for Childhood Leukemia in Iran, Case-Control Studies Approach

Context: Few possible risk factors for childhood leukemia including environmental, genetic, and infectious causes can be explained by epidemiologic studies but the etiology of most childhood leukemia is unknown.
In this systematic review and meta-analysis, we aimed to find the relationship between prenatal and maternal risk factors with leukemia children in Iran.
Data Sources: Relevant studies published in English databases (PubMed, Scopus, and ISI) and Persian databases (Magiran, Medlib, SID, and Iran Medex)) were systematically searched.
Study Selection: The study included all case-control studies that estimated the effects of prenatal and maternal risk factors on leukemia children in Iran during years 2004 to 2016, and a standardized manner was used for the extraction of information.
Data Extraction: After reviewing all searched articles (title, abstract, and entire text), irrelevant studies were excluded and related ones were selected.
We identified 10 case-control studies. The first relative history of leukemia was associated with four times raises of leukemia in children aged 15 > years (OR = 4.58, 95% CI = 1.16 - 7.99). Other significant risk factors were mothers with birth order 3 ≤ and maternal age > 35, ORs for these factors were respectively (OR = 2.39, 95% CI = 0.79 - 3.99) and OR = 2.25, 95% CI = 1.09 - 3.41).
Our results indicate that among maternal and prenatal risk factors, birth order ≥ 3, birth weight