What will my baby look like?

Woman with baby scan

This question might have been on your mind since you found out you were pregnant. If not, perhaps it sounds a little frivolous to be thinking about such things, when all you really want at this stage is a healthy baby. But lots of expectant parents do wonder what their babies will look like and it's hardly surprising, as the possibilities are endless…

It’s incredible to think that in a few months, weeks or even days, a new person will appear in your life and while you have no idea what he or she will look like (possibly even whether your bump is a he or a she at this stage) all that is already decided by genes. So will she (we'll imagine you’re having a girl, for now) be tall or short, blonde or brunette, blue-eyed or brown-eyed, or any combination of attributes?

Who will my baby look like?

When you have your baby, she might look a bit like you and/or a bit like her dad. Perhaps she’ll have your nose and his eyes or the other way around. Or perhaps, for the first few weeks, her bald head, short neck and crinkly skin will mean you see hardly any family resemblance and she’ll simply look like a cross between Winston Churchill and ET. If so, don’t worry. It’s more than likely that eventually you’ll start to see yourself, and other family members (perhaps even the annoying ones) in her. It’s all part of the wonder of watching her grow up.

How do genes work?

I’m very fair, so didn't imagine I’d have a rosy-cheeked baby with lots of dark hair, but that’s what I got. The older she gets, the more she looks like my late father, which is also a nice surprise.

Your baby’s DNA carries the genetic information that will determine which characteristics she inherits from you and her dad. Of the 46 chromosomes your baby inherits, 23 come from you and 23 from him.

Does this mean she’ll look like a perfect combination of the two of you? She might; lots of people are a mix of their parents. She could look like she’s inherited his eyes and your nose, or your body shape and his cheekbones, or any other combinations you can think up.

Some Mumsnetters say their babies looked like their partner at first but, after a few months, started to take on their characteristics, too. Others say their babies don’t look like them at all and find it upsetting – although if this is the case, bear in mind that she may well start to resemble you more as she gets older.

Experts believe each human being contains 60,000 to 100,000 genes. This means that any mum and dad could produce 64 trillion different babies between them. Perish the thought – imagine the cost of nappies… With that in mind, it’s impossible to say what your baby will look like or what kind of personality she will have (although how you nurture her will be a major factor). The only certainty is that she will be unique.

Having said that, your baby’s genetic inheritance will mean she inherits parts of you and parts of her dad, so there is definitely enough information there to do some informed speculation. And, let’s be honest, even if it turns out to be inaccurate, it’s fun to think about while you await the big arrival.

Will I have a boy or a girl?

Humans have one pair of sex chromosomes each: as the mother, you have two x chromosomes while the baby’s father has an x and y. Sperm cells are either 'x' cells or 'y' cells. The chromosome in the sperm that fertilises your egg determines your baby’s sex.

So if an x chromosome sperm wins the race to the egg then you’ll have a girl, but if it’s the y in the sperm, you’ll have a boy. Does this mean that the father determines the baby’s sex? Afraid so. But it's not like he actually gets to pick. And the chance of having either a boy or a girl really are 50/50.

What colour eyes will my baby have?

Eye colour has traditionally been used to demonstrate the importance of dominant genes. For example, if you and your partner both have blue eyes then your baby will probably have blue eyes. However, if you have blue eyes and your partner has brown eyes then your baby’s eyes will probably be brown because brown is dominant while blue is the recessive gene.

But some geneticists argue that there are too many genes involved in determining eye colour for it be a straightforward case of dominant versus recessive. The process, they say, is more like a layering of colours – imagine mixing watercolours, if it helps – with pigment also playing a significant role. Instead of brown triumphing over blue then, your baby could end up with a variation, such as hazel or grey eyes.

Mum combing baby's blonde hair

What colour hair will my baby have?

Brown is the most common hair colour and the reason is the dominance of eumelanin (one of the pigments that gives colour to hair, eyes and skin). If there’s a lot of eumelanin in your child's genes, she will have dark hair, whereas if there’s less of it, the chances of your child having fair hair are increased.

But don’t rule out surprises. Brown-haired couples have been known to produce blonde and redheaded children and the same is true in reverse. One reason for this is that in among your own genes lurk genes from your ancestors, which you’re also passing on to your baby.

Some of these genes may be dormant in you but could be apparent in your children. Which is pretty amazing when you think about it. You just have to hope she gets Great, Great Auntie Vida's renowned flaming auburn hair, rather than Great Great Uncle Horace's famous jug-handle ears.

My son was born with a mass of fuzzy black hair and blue eyes. One year later, he has straight blond hair and brown eyes.

The other thing to remember is that the hair your baby is born with may not be her barnet for life. She could enter the world with blonde hair and go much darker as she gets older – or, indeed, vice versa. Smilarly, her hair might be curly at the beginning before straightening, as her head gets bigger and more hair grows.

If both parents have curly hair then she'll inherit yoru curls but, if one of you is curly-haired and the other poker straight, her hair might be wavy, as there's no dominant gene where curliness is concerned.

Some babies lose a lot of their hair in the early months and get a completely new 'do later on. So whatever style your baby is born with, try not to get too attached to it.

How tall will my child be?

Height is a polygenic trait, which means no single gene acts alone, and it is one of the more simple characteristics to anticipate. If you and your partner are both tall then your children will probably be tall too. The same applies to short couples. If you’re both average height then your child probably will be too, although there are always exceptions and outliers, of course.

My mum is 5’4, my dad was 5’11, my brother is 6’6 and I'm 5’9. How does that make sense?

But what about couples where one partner is tall and the other is short? You’ll probably produce a child who grows up to stand somewhere in between, so average height in other words. It’s claimed that you can get an idea by adding together the parents’ heights, dividing by two to get the average, then subtracting two inches for a girl or adding two for a boy.

Mumsnetters discuss other methods of guessing where your child will reach on the growth chart – but it must be said that none of these are scientific and all could prove to be unreliable, especially as other factors (such as nutrition and the kind of environment you raise your child in) can affect what height she grows to.

Which features will my baby inherit?

You and your partner probably have some features you'd like to pass on to your baby – and others that you hope will end with you. So what are the chances of your baby inheriting your most loved or loathed characteristics?

  • Freckles. The main gene for freckles is MCR1. Everybody has two copies of this gene but it comes in two versions – freckle (F) and non-freckle (f). The capitalised F gene is the dominant one. If you have freckles then one of your parents must have passed an F on to you. They might have given you the f too, but that one doesn't really matter. The question is, will you or your partner pass on a F(abulous) freckly gene to your baby or will she just get a f(orgettable) one?
  • Dimples. Plenty of people get dreamy about dimples and regard them as marks of beauty. But dimples are, strictly speaking, genetic defects caused by shortened facial muscles. That said, if you have dimples then your baby has about a 50% chance of inheriting them. If you and your partner are a double dimple couple then the chances are increased.
  • Crooked Teeth. Are your gnashers hereditary? Experts aren't sure – and continue to argue about it – although a lot of recent research points to the line-up of your teeth being down to jaw development. Causes for crookedness include thumbsucking, breathing through the mouth instead of the nose, and reverse swallowing (pushing the tongue up against the teeth while swallowing). Keeping these to a minimum will improve your child's chances of a straight smile.
  • Receding hairline. Your hairline is affected by the dihydrotestosterone (DHT) gene which acts on the follicles at the sides of the forehead. So, if both you and your partner have receding hairlines then your child has a good chance of having one too, especially if they're male. But hopefully you can pass down some hair styling tricks to them as well.
  • Jawline. If you or your partner has a distinguished jaw then you may well want to pass it on to your child. Facial genetics, however, are pretty mysterious and scientists are still trying to work out how genes inform facial structure. If you're determined to cultivate a sharp jawline, there are exercises that will help (should you have nothing better to do with your newborn). But truth be told it's probably best not to place any bets on baby's facial features.

We're a long way from being able to put together a portrait based on parents' DNA – and that's probably a good thing (it sounds a little creepy to be honest). But rest assured – good looking couples tend to make good looking babies, while the rest of us just resent you. But more importantly, you're sure to think your baby is the most beautiful human ever created, no matter which specific attributes they do or don't have.

What Mumsnetters say about their babies' appearance

“I expected to have brown-haired and brown-eyed children, but my two children turned out to have light brown hair and blue eyes.”

“There are redheads on both sides of our family. I was hoping at least one of my children would inherit it. My eldest daughter was born with almost black hair which all fell out and grew back blonde, then turned light brown. My youngest daughter was born with fiery red hair which has mellowed to a light coppery ginger. I hope it stays that way. I will happily dye my brown hair to match!”

“I've noticed that very often babies look like their fathers in the first few months (up to about 8/9 months) and then, as they get older, look more like their mums.”

“My eldest son looks like I expected – ash blonde hair and big black-brown eyes. He’s like a more extreme version of me, as I have blonde hair with brown eyes. My younger son is showing signs of being a more gingery blonde, which I hadn't expected. But they are both more indescribably beautiful than I could ever have imagined.”