Baby Getting Pregnant

Understanding Cross-Currents In The Gene Pool

Baby hair and eye colourBefore your baby’s even opened his eyes for the first time his infant eye and hair colour are determined, stamping his impending arrival on this world! It is as if a busy 24/7 factory has been operating behind his eye lids and beneath his scalp. And then to every mother, regardless, out pops perfection! All -manufacturing completed.

Caucasian babies are often born with blue eyes but these usually change within the first 6 months. But what determines these infant hues? Pretty much it simply comes down to genetics and the three Ms: mood, melanin and medications.


Mom’s meds

If Mom is taking medication this can often affect the colour of baby’s hair and eyes to some extent, as can his mood just as our moods can influence our eye colour.

But the largest colour determining catalyst is the gift from his parents! Genes from a mother and a father can produce up to 64 trillion different children, with between 60 000 to 100 000 genes in each person. Your baby will receive 23 chromosomes from each parent which accounts for how similar, yet different, a child can be from his parents.

His eye and hair colour are just two aspects pulled from the pool of all these genes. So boys, don’t give your partner the death stare when Johnny’s eyes take on the piercing blue colour of your neighbour while you and your partner both sport hazel peepers!


Good genes, bad genes, blue genes, green genes…

In a nutshell, the gene for blue eye colour is recessive, meaning you need two genes for blue eyes to actually have blue eyes. But the gene for brown eyes is dominant, so you only need one gene for brown eyes to model brown eyes. Therefore, if someone has one gene for blue eyes and one gene for brown eyes (the body usually has two genes for most things like the shade of our eyes and our hair, or how tall or how short we are, getting one from each parent), your baby will have brown eyes.

But even if both parents have brown eyes, they could each have one gene for blue eyes. If each of them pass this gene on to their baby, then the child will have two genes for blue eyes and then actually have blue eyes.


The domineering one

The gene for green eyes is also dominant over blue eye colour, but at the same time it is recessive to brown. So if your partner has green eyes and you have brown eyes (both dominant colours) it boils down to the fact that your baby could have almost any eye colour from hazel to blue. Research has not yet managed to solve that mystery in its entirety yet!

There are also certain medical conditions which can cause a changing of the eye colour in all ages, from babies to old age.


Horner’s Syndrome

This can include Horner’s Syndrome which presents as a problem with the third cranial nerve. If Horner’s Syndrome, a droopiness of one eyelid with a smaller pupil in that eye than in the other, afflicts a child younger than one year the likelihood of that baby’s eye colour lightening in just the one eye is high.


It’s a protein

The protein, Melanin, which is in our systems from conception, plays a vital role in colour definition, too. It is like a salon hair tint to artificially darken our hair to cover our signs of aging.

As is the case with everything about our make up, Melanin is coded in our genes but it is the density of this protein that determines the darkness of our hair and eye colour.

Our bodies increase the production of Melanin from the first year of our lives. This can result in your white-blonde-haired angel turning dark in hair colour. Our bodies are full of surprises! It is when our babies reach around the sixth month mark that their Melanin -rations start to settle down and the stage is pretty much set for eye and hair colour!


 – Bev Sinclair


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