Risk factors predisposing children to transient hypogammaglobulinemia of infancy.

Introduction: Transient hypogammaglobulinemia of infancy (THI) is a heterogeneous disorder characterized by reduced serum immunoglobulin G (IgG) levels in early infancy. Objective: This study aimed to identify potential risk factors associated with THI. Methods: Children with THI and normoglobulinemic healthy children were compared by using a questionnaire that addressed possible risk factors. Results: In total, 108 participants were enrolled, 54 patients with THI and 54 healthy controls. The median age at diagnosis of the patients with THI was 17 months (range, 4-38 months), and 40 (74.1%) were boys. In the control group, the median age was 22 months (range, 16-61 months), and 27 (50.0%) were boys. Male sex (p = 0.004), cesarean section birth (p = 0.003), low maternal education (p = 0.001), low paternal education (p = 0.004), analgesic use during pregnancy (p = 0.001), antibiotic use during pregnancy (p = 0.001), multivitamin use during pregnancy (p = 0.001), gestational diabetes or preeclampsia (p = 0.039), smoking exposure (p = 0.001), atopic disease (p = 0.001), and familial atopy (p = 0.001) were associated with THI, whereas low socioeconomic level (p = 0.001) and breast-feeding for > 6 months (p = 0.032) were less likely in the THI group. Conclusion: There are several features of pregnancy history and family demographics that are associated with THI.