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Nub theory explained: Predict your baby's sex at 12 weeks

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baby scan, ultrasound, boy or girl, pregnant, pregnancy,

Can you tell if your baby is a boy or girl from just 12 weeks? We've all heard of the old wives tales like carrying your baby bump low means it's a boy or if you're craving sweet things, you're expecting a girl.

However, the nub theory claims to be a lot more accurate - and says you can even tell the sex of your baby just by looking at your 12 week ultrasound picture. Usually the earliest point you can tell the sex of a baby from a scan is 20 weeks so the quirky theory is popular with those who can't wait to find out if they're having a little girl or a little boy.

What is nub theory?

Between 11-13 weeks, all babies are said to have a 'nub' between their legs called the genital tubercle, and according to this theory the angle of the nub will indicate whether it's a boy or girl.

It's said that if the nub is over 30 degrees up from the spine, it's a boy - but if it's under that then it's a girl.

Confused? See our pictures below as an example.

Nub theory indicating a girl

Nub theory - girl picture
The nub isn't pointing up more than 30 degrees from the baby's spine - in fact it's almost horizontal - so believers would say this showed the scan to be a little girl.

Nub theory indicating a boy

Nub theory - boy picture
The nub is at a much steeper angle upwards from the spine, indicating that this could be a baby boy.

Not convinced? Netmums have reported the following statistics inline with the nub theory:

  • At 11 weeks, the accuracy rate is 48 per cent

  • At 12 weeks, the accuracy rate is 91 per cent

  • At 13 weeks, the accuracy rate is 94 per cent

  • Going for your scan soon? You'll have to hope for co-operation from your baby as some professionals say the accuracy actually all depends on the angle of the baby. If you can get a picture of them laying down on their side, that should provide you with a good view of the nub.

    Continued below...


    If you had success using the nub theory then we'd love to know! Leave us a comment below or send us a message on our Facebook page.

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