Early Gender Prediction – Genital Tubercle Angle

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If you remember a few months back I was desperate to find out if Alexis was a boy or a girl.

I always wanted a girl. It’s been my dream to have a blond cute little daughter, who’d adore her daddy, and wear pigtails, and love pretty dresses. A girl who will be afraid of bugs, and mimic her mommy and have this adorable girly voice. I want to have talks about boys, and girlfriends, and school, and cheerleading or any sports she’ll play. I want to know everything about her first crush, and her first kiss. I want to go clothes shopping with her, and do our hair and make up. I want to do all the girly things there are to do and all the boyish things she might want to do as well.

{Little girl borrowed from and photo taken by my talented friend Leeka}

So needless to say, we did everything we could to tip our chances towards having a girl. Granted, there’s not much one can do to help that ( if anything). We followed Shettle’s method and  although it hasn’t been proven accurate, it was the ONLY thing that made sense logically and (pseudo-)scientifically.

And then we crossed our fingers and waited. It turns out  four  months is a long time to wait when you have a strong preference about the sex. So some time during those 4 months, I bumped into  a way of determining the sex of the baby earlier (here).  And it was not one based on old wive’s tales or via any kind of invasive procedure.

It’s called genital tubercle angle method and it can be used to determine sex at 98.7% accuracy at your 12-14 week ultrasound. The keyword is “CAN”. It’s not a sure thing (nothing is, until you give birth), it’s more of a speculation, but it’s no different than determining sex at your 20 week ultrasound.

So here’s how it works:

The ultrasound technician takes a scan of the baby “from the side” and looks for the baby’s nub. At this point in pregnancy the genitals aren’t developed enough to look much different, whether it’s a boy or a girl. It all looks like a little nub between the fetus’s legs. However, what’s indicative of the gender is the angle that nub is pointing at. If the angle is 30% or more to the baby spine ( spine not the uterine wall), then it’s indicative of a boy, if it’s parallel or less than 30%, then it’s a girl.

As you can tell, such a measurement leaves a lot of room for error and the technician would have to be trained or experienced in this type of gender determination to say anything definitively. However, for anxious parents, like we were, it could at least give some idea.

The problem becomes when the angle isn’t clear. All babies develop at their own speeds and one baby might point parallel at 13 weeks but then rise up over 30% (a boy), and another baby can have an obvious boy nub at 12 weeks. However, obviously boyish nubs almost never turn out to be girls.

Our technician was not willing to even look at that type of thing, though our OB was very intrigued. We were disappointed to not even get a little clue at 12 weeks, but there was nothing we could do….

That was until one of my readers pointed out that I could extract a single frame from the ultrasound video we shot at the appointment, where you could see the angle of the nub. I don’t know why it hadn’t occurred to me prior to that, but I loved that idea. So I got that one frame and studied it closely. To me it looked like the nub was pointing down, but I could have been inventing things, because I wanted a girl so bad. I texted my friends the picture and the explanation to see if they are seeing the same thing, but they couldn’t really tell.


So that same reader sent me a link to the InGender Forums, where, it turns out, there’s a whole section devoted to just that: Genital Tubercle Angle.  You can view the 12 week ultrasounds of babies and their CONFIRMED gender to get a better idea of what a boy or a girl nub tends to look like. It’s not always clear. Sometimes, what LOOKS like it could be a girlie nub turns out to be a boy. But I’d say in 80% of the ultrasounds I saw,  (without any experience) I could easily guess the sex correctly. Also you can post a picture of your baby’s nub, and women who have seen quite a few of those, including some ultrasound techs, would attempt to give you their guess. Needless to say, I promptly uploaded that pic and within a day got 8 or 10 GIRL guesses.

That made me pretty sure we were having a girl. I didn’t want to say anything o
n the blog for two reasons: in case it wasn’t correct, and not to spoil the gender reveal.

Well, as you all know, it turns out we ARE having a girl, so I thought I’d write about this method for all those other anxious parents out there.

I found it a lot of fun to speculate and guess and study the ultrasound. It was completely a part of the whole excitement to find out the sex of our baby. I wouldn’t have been disappointed in the method if it was wrong and I am definitely going to try to figure out the sex of our next baby when that time comes. However, if you’re the kind of person, who doesn’t deal with disappointment well and has a VERY strong preference, you might want to use this resource with caution.

For everyone else, HAVE FUN!

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  • Reply
    October 10, 2011 at 4:50 PM

    Okay. Now I’m intrigued too! I am going straight to my early ultrasound photos when I get home to see if I can see a nub. I know he’s a boy, but still want to see if I can see it.

  • Reply
    July 23, 2012 at 4:33 AM

    we have been looking for a method for some time, especially something non-invasive and non-manipulative. one we came across is by Dr. Schoun and looks promising.

    For all interested his site is here: http://babymethod.com

    his methodology: http://babymethod.method.html


  • Reply
    June 7, 2014 at 7:07 AM

    Where can i upload my ultrasound video to see if anyone can guess the gender?

  • Reply
    August 3, 2015 at 7:31 PM

    I had an ultrasound today at 12 weeks, and right off the bat the UT tech said that she could tell the gender. We are wanting to do a gender reveal so I told her not to say it out loud. However, when I looked at the screen, I noticed she was looking from the underneath angle, or potty angle I guess some call it. From my research, it seems that at this early, the genitals had to be seen from the side in order to have a good idea of the gender. She said she was 100% though, is this even possible? I am pretty sure she is thinking boy, because what I saw looked like boy, but I know at this stage both genders have genitalia that looks like a penis.

    • Reply
      Elena @The Art of Making a Baby
      September 3, 2015 at 4:38 PM

      Yes, from what I know, you are correct. It’s highly unlikely that she would be able to see an actual boy penis from that angle correctly. I would definitely wait to do a gender revel till 16 weeks when you can see. In the meantime you can look at the proper angle of U/S and speculate 🙂

      • Reply
        October 2, 2017 at 1:16 PM

        It’s 7th week now !! Underwent ultrasonic scanning , Any Possibility to find the gender ?

        • Reply
          Elena @ Every Avenue Life
          October 7, 2017 at 12:46 PM

          t’s most likely too early! Get one at 12 weeks or later and you’ll be able to see. At 7 week the genitals are developed enough to see the angle

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