This simple test using your baby’s 12-week scan is believed to be 92 per cent accurate in predicting your baby’s sex.

Called the “skull theory”, the idea is that you can tell your baby’s sex from the shape of their skull in the picture.

To test it out, you need to have:

  • your 12-week scan picture
  • a magnifying glass
  • info on skull shape and size

According to Netmums, boys do tend to have bigger heads and girls have rounder heads in their scan pictures.

Try it out and see if it is true!

skull

Skull theory: it’s a boy!
Here’s what the skull-theory believers say are the clues to look for that will reveal you’re having a boy
  • The male cranial mass is more blocky and big compared to the female’s, which is rounder and tapers at the top.
  • The temporal ridge which runs along the outer side of the upper skull creating the square shape of the upper head is more prominent in males than females.
  • A male’s supraorbital margin  the ridge above the eyes – is round and dull.
  • The zygomatic bone – the cheekbone that lies under the lower eye ridge – is more pronounced on the male skull.
  • The mandible or lower jaw bone  of a male is squared, unlike a female’s, which is rounded.
  • The male forehead  is lower and more sloping.
  • Men have a deeper cranial mass .
  • The superciliary arch is large and pronounced in males.
  • The male’s gonion – the most lower rear point on angle of the lower jaw bone – is more flared out and sharply angled.
  • The teeth of males tend to be larger.
Skull theory: it’s a girl!
Here’s what the skull theory believers say are the clues to look for that will reveal you’re having a girl
  • The temporal ridge, which runs along the outer side of the upper skull creating the square shape of the upper head is less prominent in females than males.
  • The female cranial mass  is rounder and tapers at the top.
  • A female’s supraorbital margin  – the ridge above the eyes – is sharper and less rounded than a male’s..
  • The zygomatic bone  – the cheekbone that lies under the lower eye ridge – is less pronounced on the female skull.
  • The lower jaw bone of a female is more rounded, while the male’s is squared.
  • The female’s forehead tends to be higher and less sloping.
  • Females don’t have such a deep cranial mass.
  • The superciliary arch is smaller and less pronounced in the female.
  • The female’s gonion  – the most lower rear point on angle of the lower jaw bone – is less flared out and less sharply angled.
  • A female’s teeth tend to be smaller.

Share your comments below


  • Interesting. I’d still rather go by looking for an appendage or lack of one. And still would be prepared for it being a surprise.

    Reply


  • But wouldn’t you need to have your scan and a scan of a boy baby and another of a girl baby so you can compare them? I’m thinking if I was looking at one of my scans, I wouldn’t be equipped to say “it’s a rounder head, she’s a girl”

    Reply


  • We didn’t find out with our first but we had fun with all the wives tales that had different results.

    Reply


  • wow, I had 3 boys, no comparison, interesting

    Reply


  • I never thought of this idea nor cared enough to try it. Most likely it would not help determine the sex so I just go with what the ultrasound lady says and when bub comes out.

    Reply


  • We never found out the sex of our baby when I was pregnant, although we (just for fun) tried out a few of these theories…It was wrong for us

    Reply


  • I’m not sure I ever cared enough to go to this much trouble.


    • We were happy to wait and be surprised – mystery is a good thing.

    Reply


  • Interesting. We never fell the need to find it out though.

    Reply


  • I’m just excited and can’t wait to find out at our 20 week scan


    • Congrats , I’m excited for you too ;)

    Reply


  • That’s interesting. My daughter was just moving so much during the scans, that I don’t think it would have been of much help for me. :-)

    Reply


  • Never any desire to know before the birth.

    Reply


  • Would love to see some research on this and find out if it is true.

    Reply


  • I don’t think the hospitals use that is definite indication of the sex before birth. If a baby has legs crossed they can’t tell you the sex. One Mum didn’t find out until 3 weeks before the birth.

    Reply

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