Risk Factors for Rickets of Prematurity in Extremely Low Birth Weight Infants

Abstract

Purpose : This study aimed to analyze the risk factors for the development of rickets of prematurity in extremely low birth weight (ELBW) infants.

Methods : We retrospectively reviewed the data of 57 ELBW infants. Nineteen infants were diagnosed with rickets and 38 infants without rickets were recruited. On radiologic evaluation, 47% of infants had grade I, 37% had grade II, and 16% had grade III rickets.

Results : In ELBW infants with rickets, the durations of oxygen administration, mechanical ventilation, parenteral nutrition, and hospitalization were significantly longer compared to those of the control group. The number of days for achieving an enteral caloric intake of 80 kcal/kg/d and the number of days for regaining birth weight were significantly longer compared to those of the control group. Serial weight changes from birth weight during 8 weeks after birth was significantly lower in the rickets group than in the control group. Retinopathy of prematurity was significantly higher in the rickets group than in the control group. After adjustment for birth weight, rickets of prematurity was correlated with days for regaining birth weight (odds ratio [OR], 1.316; P=0.010), and with weight changes from birth weight at 4 weeks of age (OR, 0.964; P=0.033).

Conclusion : In ELBW infants, the risk factors for rickets of prematurity were days for regaining birth weight from birth and the weight changes at 4 weeks of age. Early aggressive nutrition for regaining birth weight earlier may reduce the development of rickets of prematurity.