Objectives: To examine the influence of duration of completely or partially wrapped swaddling on rickets onset and bone properties in children of school age.
Study design: Case-control study.
Methods: Subjects were 73 children aged 7-10 years with a history of rickets (cases) and 70 children with no history of rickets (controls) in Ulaanbaatar, Mongolia. The periods of completely and partially wrapped swaddling, rickets onset and age-standardized mid-tibial cortical speed of sound (TCSOS) were examined. The associations between swaddling duration and rickets onset and that between swaddling duration and TCSOS were analysed.
Results: All except one control child were completely wrapped from the first month after birth. The durations of completely wrapped and partially wrapped swaddling were similar among cases (3.6 and 4.7 months) and controls (3.1 and 4.4 months) (P=0.42 and P=0.65, respectively). Standardized TCSOS values of cases and controls were -0.572 and -0.038, respectively (P=0.06). The duration of swaddling did not show associations with rickets onset and standardized TCSOS among both cases and controls. Standardized TCSOS of cases with skeletal deformities at examination (-1.467, n=18) was lower than that of cases without skeletal deformities (-0.280, n=55) (P<0.01) and controls (-0.038, n=69) (P<0.001).
Conclusions: The practice of swaddling itself neither influences rickets onset nor bone properties in school-aged children in Ulaanbaatar. Bone properties of school-aged children who had suffered from rickets and with skeletal deformities were poorer than those in children without skeletal deformities and children without a history of rickets. Prevention of persistent skeletal deformities among the children who have suffered from rickets is critical to promote healthy bone development in Mongolia.