The causes of newborn hair thinning, may be genetic factors, lack of nutrition, long-term non-wash hair, etc., as follows: 1, genetic factors: baby’s hair has a lot to do with genetics, if the parents’ hair is black and more, the child will often do the same, and vice versa, the parents’ hair is thinner, the baby naturally will not be more. If the baby is healthy, all aspects of development are not a problem, parents do not need to worry excessively. 2, lack of nutrition: healthy growth of hair needs protein, vitamins, as well as iron, zinc and other trace elements. If the baby mother in pregnancy for some reason, resulting in inadequate intake of nutrients, resulting in malnutrition, if not improved in time, the baby will be born with thin hair and relatively thin phenomenon. 3, long-term not wash hair: because the baby hair is thin, parents dare not wash the baby’s hair, lest the already small hair washed away, long-term not wash hair, oil, sweat glands plus the shedding of dander piled up on the scalp, but affect the growth of new hair.