Newborn baby hair loss – why does it happen?

Being a new parent is daunting to say the least, especially as, in your baby’s first weeks and months of life following their birth, you can expect some pretty big physical changes to take place. Babies grow at an incredibly fast rate that can seem a little alarming – but there’s nothing to worry about! Neither should you worry if it seems like certain aspects of your baby’s growth aren’t going as expected – like if his or her head-full of hair starts to become thin and patchy, in some cases leading to baldness.

You can rest assured that, worrying as it may seem, hair loss in your baby is nothing to feel concerned about. It’s back in the first trimester of pregnancy that the foetus starts growing the first hairs on his or her head. This doesn’t happen in all cases – some babies are born with only the thinnest coating of fuzz – but what is a definite is that all babies, after birth, will lose some hair. The reason behind the hair loss is that your baby is adjusting physically to life beyond the womb (which can take some getting used to, as you can imagine).

You probably already have some idea about how hair growth works in adults: each strand of hair goes through a phase of growth and non-growth, and when hair isn't in the growing phase, it’s pretty normal for it to fall out. You should never really notice if your hair is shedding – it’s completely normal, and is usually replaced by new strands that are growing at a near-constant rate.  You only lose around 50 strands a day, topping at 100. Newborns, however, can lose a lot more.

The reason why newborn babies lose more hair all at once is because of the hormonal shifts that take place inside a baby's body after he or she is born. These changes directly trigger all of the baby’s hairs to move into the non-growth phase at the same time, which is what causes the noticeable hair loss – because nothing is growing back to replace it.

Childbirth leads to huge hormonal changes for both the mother and the baby, during labour and following on, which need to take place for the birth to be successful. When labour begins, your baby’s body naturally begins to generate hormones that help the baby to adjust to a life out in the real world.  

One of these hormones is called cortisol. You might know it as the stress hormone, but it can also be incredibly helpful in the early stages of a baby’s life. As well as enabling the baby’s lungs to mature, it also helps the baby's body to create its own energy and heat. During labour, cortisol is produced because of the stress of the birth – but it’s a positive stress, triggering changes that the baby needs to survive. This means that the less important functions, such as hair growth, as put on the back bench while your baby adjusts to surviving outside of the womb.

In the weeks and months following the birth, all of your baby's hair stays in the non-growth phase while his or her hormones focus on the more important task of keeping them alive and healthy. You can expect for your baby’s hair to start to shed at between 8 and 12 weeks, but don’t worry, it’ll grow back after 3 months to half a year’s time.

Still, baby hair will remain thin and wispy until your infant reaches the age of around two, when you can expect to see a significant increase in thickness. However, it’s worth bearing in mind that all hair growth and loss patterns are different, and vary from baby to baby depending on a number of factors, including age, sex, genetics, and even the type of birth.

What else can you expect to see from a baby’s hair during growth? Well, for a start, your baby's hair colour and texture may change on a number of occasions during their first few months or years. It’s hard to understand why, but it’s thought hormones might play a part in things, as they always do. So, a word of warning: if you’re in love with your baby’s hair as it is now, try not to let yourself get too attached!