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. Objectives: 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 ۲۰۰۴ to ۲۰۱۶, 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. Results: We identified ۱۰ case-control studies. The first relative history of leukemia was associated with four times raises of leukemia in children aged ۱۵ > years (OR = ۴.۵۸, ۹۵% CI = ۱.۱۶ - ۷.۹۹). Other significant risk factors were mothers with birth order ۳ ≤ and maternal age > ۳۵, ORs for these factors were respectively (OR = ۲.۳۹, ۹۵% CI = ۰.۷۹ - ۳.۹۹) and OR = ۲.۲۵, ۹۵% CI = ۱.۰۹ - ۳.۴۱). Conclusions: Our results indicate that among maternal and prenatal risk factors, birth order ≥ ۳, birth weight < ۲,۵۰۰ g, and first relative history of leukemia increased the risk of childhood leukemia; in contrast, breastfeeding was a protective factor.

Keywords:

Child Leukemia , Leukemia , Leukemia , Risk Factors , Systematic Review