Nub theory: How to predict your baby's gender at 12 weeks
Categories: Babies, Pregnancy & birth, Development
If you are pregnant or are thinking of getting pregnant and do NOT want to know the gender of your baby, you MUST NOT READ THIS ARTICLE.Go away. Read something else. Go on. Go!.... I'm waiting.... Seriously. You can't read this.... Er... are you still there? No? Good. OK. Now, to the rest of you...
For centuries, people have been claiming they can predict the gender of your baby whilst you are still pregnant. Some say that you're having a boy if you're carrying all out front or low and a girl if you're carrying all around and high.
Or there's the old 'wedding ring over the belly' trick - if you tie your wedding ring onto a string and hold it over your belly, apparently the way it swings can tell the gender - if it moves in circles it's a boy, side to side it's a girl.
Other predictions involve the state of your skin or your hair, your mood, whether or not you had morning sickness, the shape of your nose, the colour of your urine, the exact age you were when you conceived, even the position you were in when you got pregnant.
Unfortunately, for anyone who has wanted to actually find out what sex their baby is, none of these old wives tales has any bearing in reality whatsoever. They may be fun to do, but they aren't going to give you any clear cut answers.Ultrasound scans finally made it possible to see whether you were having a girl or a boy. Until fairly recently, one would have to wait until the 20 week scan or later to see the genitals clearly. 20 weeks, of course, is a long time to wait if you really, really want to know.
Now though, research is being done into whether or not the gender of a fetus is obvious at the 12 week scan. At the moment, most sonographers will say that they cannot tell you the gender of your baby at your first scan. This is, perhaps, because they aren't aware of 'the nub theory'.
I had two 12 week scans with my current pregnancy - one on the NHS, one privately at the Fetal Medicine Centre - the sonographer on the NHS one told me categorically that the gender was undetectable, the sonographer at the FMC told me that she was 75% positive it was a boy (my 20 week scan confirmed that I am, indeed, having a boy).
The nub theory is basically about 'the angle of the dangle'. Between 11 and 14 weeks' gestation both genders have a penis-like protuberance between the legs. They look incredibly similar at this point, except for the angle at which they are pointing. Sometimes there are males and females at this stage which are in the 'grey area', but essentially a boy's 'dangle' is 30 degrees up relative to the backbone and a girl's is below 30 degrees.
In order to be able to have any chance of predicting the gender, the foetus must not be curled up- they need to be lying as flat as possible. Also, it must be side on and apparently, it is better if the foetus is right side up.
OK, here are some examples. First, my soon to be born little boy at 12 weeks. I've put a red arrow in pointing to his 'nub', which as you can see is pointing 'up'. Some male foetus shots I've seen have been pointing almost straight up.

Here is a shot of a girl. You can see her nub is pretty much horizontal. You can also see that her nub looks forked at the end. Some people think this means it is more likely that it is a girl, but a fork can be seen in both genders.

If you get your scan at 11 weeks, it can be difficult to tell the difference between the genders. A scan at 12 weeks is around 75% accurate and at 13 weeks it's closer to 95% accurate.
When you go in for your scan, ask your sonographer 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'.
There is loads of information online about the nub theory. This site has photographs showing the differences between the genitals and includes examples of ultrasound images.
If you've already had your scan and the nub is visible, but you can't work out if it's a boy or a girl, why not go to the In Gender Forum where you can post up your scan on the boards and get members to have a look and make their predictions. There are also threads on which members post up their scans AFTER the gender has been confirmed either at the 20 week scan or at birth.
















Reader Comments (Page 1 of 2)
J 8-13-2009 @ 4:22AM
Nub Theory.
Boy or girl? ultrasound (14 weeks)
http://www.flickr.com/photos/40282423@N03/3720469349/
Thanks :)
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KRIS 11-24-2009 @ 2:34AM
I was wondering if the shape of the nub makes a difference
of what the gender could be? It looks like the boy nubs have a triangle kinda shape to the tips .
Reply
krissy 11-23-2009 @ 7:52PM
I was wondering if the shape of the nub makes a difference of
what the gender could be? It looks like the boy has a triangle
shape to the tip of the nub.
Reply
Gia 11-24-2009 @ 2:36AM
Apparently the shape of the nub *isn't* a factor. Girls *and* boys have been seen with the 'forked' end as well as the 'triangle' end. What is important is the 'angle of the dangle'. ;)
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kamani 1-27-2010 @ 8:42PM
hi, i cant believe this i have the same image but i dont know im confuse can it be a boy .plz reply
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gill 2-19-2010 @ 6:53AM
i would wait off till the second scan then ask, im on number 5 and still couldnt tell you what im seeing on the scan pics lol
and i never quite believe what im having till i have them..although they have been right all along
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sara 4-01-2010 @ 3:09PM
I have an ultarsound pic and I am 13 weeks preggers. The image is showing the babies bottom and the genital look like a fork (four lines) the two inner lines protude out further than the outer lines. I was told it could possibly be a girl. Does anyone have an idea.
Please help
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jodie 4-15-2010 @ 9:44AM
Hey Sara they say that the girls labia is set with 3 / 4 lines n that what sets them apart from the boys!! I have 4 girls n all of them had this distinct lines! I just found out I am pregos again n I am thinking we may have another girl on the way I mean really the odds r against us!!! Lol we will c though! Good luck let us know what u have!!! Cheers jod
Mem 5-04-2010 @ 2:14AM
Is it a girl or boy ?
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Gia 5-04-2010 @ 2:17AM
If you are asking me (the one who wrote the article), I had a boy.
Wendy 5-04-2010 @ 2:13AM
Does it matter, they are all gorgeous and a blessing. As long as baby is alive and kicking. People are too impatient for there own selfish reasons. Medical reasons i can understand. I have four babes and have lost four, they are all boys and fantastic and i didn't feel the need to find out, even though i had several scans with all of them. Be grateful for the luck of being pregnant and think of the people who can never be, who wouldn't mind. And incase i know doubt am judged for four, we were not trying for a girl as i have been asked by some insensitive people, just the miracle of a baby; 3 were fertilty born and one a natural surprise. Surely the colour of the nursery or bits can wait until the little darling is born.
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Rayne 5-01-2010 @ 8:07AM
I totally agree with you. With my second child the sonographer just suddenly blurted out what sex the baby was going to be 'oh it's another girl' thanks mate. I didn't want to know, I wanted it to be a surprise. If I had any more children then I wouldn't want to know, after all that hard work the grand finale would be finding out what you have got. Babies don't care if their room is pink, yellow or indigo they just want to be well fed, clean and loved.
blondie 5-04-2010 @ 2:13AM
i was wondering if anyone an tell me what the nub on my baby is? boy or girl? i cant tell...
(okay how do i upload pic) lol
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blondie 5-04-2010 @ 3:31PM
okay guys, here is the picture, please let me know wht you think!!! thanks..
http://www.flickr.com/photos/blondie2010/
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Gia 5-04-2010 @ 2:20AM
Blondie, I can't see the nub in that photo. Sometimes they don't get it in shot...
nataley 5-04-2010 @ 12:54PM
this pic was taken at 13 an 1 day,, when i went for 20 week scan they couldnt see
[IMG]http://i275.photobucket.com/albums/jj298/crazyg_2008/photo003-1.jpg[/IMG]
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blondie 5-05-2010 @ 12:53PM
okay here are two pics of baby at 12 weeks and 3 days.. can you see the nub in these ones?
http://www.flickr.com/photos/blondie2010/4578674502/
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Jill 5-12-2010 @ 2:49PM
Tech said she thought it was a boy what do you think?
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Jill 5-12-2010 @ 2:56PM
Lets try this again.
Tech thought boy, what are your thought?
12w1d
[IMG]http://i133.photobucket.com/albums/q78/BabySchultz/100_1903-2-1.jpg[/IMG]
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Noemarie 6-01-2010 @ 5:01PM
this is my baby at 13 weeks. Someone please help me determine if its a boy or a girl :(
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