Newborns with curved legs may be caused by normal physiological factors, congenital hip dysplasia, calcium deficiency and other reasons. 1. Normal physiological factors: As newborns stay in the womb for a long time before birth, as they gradually grow up, the space will become smaller and smaller, so in order to adapt to the intrauterine development, newborns need to be curled up in the womb limbs and thus the phenomenon of curved legs may occur. 2. Congenital hip dysplasia: congenital hip dysplasia refers to the congenital factors that lead to abnormal development of the hip joint structure, due to congenital hip dysplasia, it may lead to newborn babies to appear leg bending, asymmetry of the two sides of the leg pattern phenomenon. 3. Calcium deficiency: the growth process of the newborn’s demand for calcium is very large, if the calcium content of breast milk is not particularly high, it may lead to the newborn’s calcium deficiency phenomenon and thus lead to the phenomenon of bent legs. Newborns with bent legs, it is recommended to go to the hospital in a timely manner to identify the cause of the disease and give appropriate treatment, in daily life, to strengthen the nutritional composition of the supply, so that the newborns enough calcium to improve the phenomenon of bent legs.