It's funny to see how parents with brown or very dark hair have a baby with platinum hair. And even the other way around, babies who were born blonde end up as dark-haired children.
Why does this happen? What determines hair color? The answer lies in genetics, the hair color of parents or sometimes grandparents or great-grandparents is responsible. Definitely it is determined in DNA.
Brown, blonde, red-haired, black-haired babies ... there are infinite shades of hair. Hair is colored due to a substance called melanin, which also colors the skin and eyes. Genes will determine the concentration of melanin and this will produce one hair color or another.
There are two types of melanin: eumelanins, responsible for dark hair, and pheomelanins, for light hair. According to the concentration levels of each of them, we will have as a result the natural color of the hair.
Babies at birth have a lower concentration of melanotics, but as they grow and are exposed to the sun, the number of melanotics increases and thus the color of the skin and hair is more intense.
This also explains why hair color changes as we get older. In adulthood, melanin decreases and then the hair begins to thin, that is when gray hair appears, that is, hair without pigment.
Melanin is also responsible for babies having blue eyes at birth. The iris of the eye, that is, the colored part, has little pigment, has received little light, and acquires a bluish color.
My children were all born with a good head of very straight black hair. However, they all lost it to have a very different type of hair in all cases. Hormones during pregnancy are responsible since they act during pregnancy in several ways, one of them activating the growth of the baby's hair.
After the birth the effect disappears and the hair begins to fall and another begins to grow. It is very common to see babies with bald spots in their hair, especially on the nape of the neck, which is the one that spends the most time against the crib. The hair that is being born is sometimes the same or similar to the one it had at birth and sometimes totally different.
The definitive hair of the baby will appear can appear at a year or a year and a half, and some even take much longer to have hair and up to two years they only have a fine and delicate fluff.
You can read more articles similar to Why Some Babies' Hair Color Changes, in the category of on-site development stages.