Anemia During Pregnancy and Molar Incisor Hypomineralization in Children and Teenagers: Systematic Review and Meta‐Analysis

Molar incisor hypomineralization (MIH) is an enamel defect that has a systemic origin and affects at least one permanent first molar and incisors. The present systematic review aims to answer the question: "Is there an association between maternal anemia during pregnancy and the occurrence of MIH in children and adolescents?" Studies in children and teenagers affected with MIH compared to healthy children and teenagers, assessing anemia in the gestational period, with no data or language restrictions, were eligible. The search in eight databases was performed up to January 2024. Quality assessment was assessed using by Newcastle Ottawa Scale tool. The association between anemia during the gestational period and the MIH was assessed by odds ratio (OR) and its corresponding 95% confidence interval (CI) in the RevMan software. The certainty in the body of evidence was assessed for pooling of outcomes using the GRADE approach. One case-control and three cross-sectional studies were included. A positive association between anemia during the gestational period and MIH was measured (OR 1.84 [1.28; 2.65]) (biases were detected). The results show with a very low certainty of evidence that anemia is associated with greater involvement of MIH in children and teenagers.