Baby Gender – Can You Predict It?

baby gender

Now we know that there are plenty of “old wives tales” for people who want to check the gender of their baby. There is the wedding ring over the tummy (you know the one, where you tie your wedding ring onto a string and depending on the way it swings over your pregnant tummy it can tell you if you are expecting a girl or a boy). OK, not convinced with that one? How about the colour of your urine… or what about how you carry the child during pregnancy (a boy if it’s low and a girl if it’s high).

Predicting Baby Gender – Is It Possible?

Soothsayers have been claiming they can predict the gender of your baby for as long as anyone can remember. Some predictions are as strange as studying the shape of your nose and some are as ridiculous as relying on the “position of conception”. However, for anyone who has genuinely wanted to know the gender of their baby, the clear cut answers rely on ultrasound scans. And typically you would need to wait until the 20 week scan or later to clearly see the genitals.

So what if I told you that you can find out the sex of your baby at week 12… with a 75% degree of accuracy! You don’t believe me? Well, it’s true and it’s called “the nub theory”. This basically relies on the “angle of the dangle” and it’s a fairly new technique. It basically works like this: between weeks 11 and 14 the foetus has a small bump between the legs.

Until recently, sonographers (the people that read your scan) haven’t been able to conclusively predict the baby’s gender at this stage because the protuberance occurs in both males and females, and the look almost identical. However, recent studies show that there is, actually, a difference that can be spotted even as early as at the 12 week scan. Essentially a boy’s dangle is 30 degrees up (hardly a dangle, in my opinion, and a very boyish trait already!) and the girl’s is below 30 degrees. Both dangles are measured relative to the backbone.


OK, so it’s not all that easy. There are “grey areas”, where it’s really not possible to see at this stage which way the bulge is leaning, but in essence the system works. The other challenge is that the scan has to be of the foetus lying as flat as possible as it’s very difficult to predict the gender when he or she is all curled up. Also, it must be side on and apparently it is better if the baby is right side up.

So there you go… need some proof? Look at this.


This is a scan taken at 12 weeks. Can you see the little protrusion near the top right corner of the picture. That is the “nub”, and as you can see it is at an angle of greater than 30 degrees relative to the back bone.


OK, now let’s look at the female equivalent. Once again, this scan is taken at the 12 week milestone (the end of the first trimester). And there you can see it; the nub is less than 30 degrees on this picture… and it really is very clear. Given that these two scans were taken at the same time, there is quite a difference, don’t you think?

Remarkable, but true! If you get your scan at 11 weeks, it can be difficult to tell the difference between the genders. If, on the other hand, you check the 12 week scan, you can predict the gender of your baby with a 75% degree of accuracy (at 13 weeks it’s closer to 95% accurate). When you next go in for your scan and you start talking about “nub theory” and checking the picture, be aware that some sonographers aren’t conscious of this theory so don’t be put off when they look at you like your crazy. Just ask to get a shot exactly like one of the ones above; the foetus right side on, back flat not curled up and a good shot of the ‘nub’ and you can do the rest.

That is, of course, if your keen to find out the gender of your baby. Personally, I’d rather be surprised, but that’s just me.

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