The Myth of Early Fetal Sex Determination
As a sonographer of many years, I know that ultrasound is subjective. But expectant moms seem to continue to be surprised by incorrect early fetal sex determination. And I seem to be receiving more and more emails about this ever-growing problem. Nothing makes me angrier than when another sonographer tries too early to hand out a sex guess! I get angrier still when some businesses make this promise as a marketing ploy.
It just isn’t fair to the patient or customer. I feel these facilities take advantage of pregnant anxious moms who have a desire to know the sex of their baby as soon as possible. After all, it is one of the most anticipated events in pregnancy! However, these mothers-to-be wouldn’t spend their money on an ultrasound if 3D non-medical businesses didn’t exploit that desire. They advertise a promise or guarantee for early fetal sex determination at 12+ Weeks! So, what is the public to believe except that they can deliver on that promise? The truth is they know it’s only a guess. If they guess right, they got lucky. If they guess wrong . . . oh, well. Here’s some of your money back.
I think developments in the technology have yielded a little too much ambitious guessing in the fetal sex department. Resolution has improved so greatly over the years that we see better than ever with the most modern equipment. But just because we can see “a little something” sticking out, in no way or shape or form, means you’ll be investing in blue paint.
I want to educate every fertile, human-growing woman or parent-to-be out there that even the best
ultrasound equipment on the planet cannot differentiate a boy from a girl.
To this day, determination of sex is still dependent on the experience and skill of the person holding that probe to your belly. But also know that a sonographer’s skill doesn’t mean squat when external genitalia has just begun to grow. It’s anyone’s guess!
We have all heard a similar story. A customer pays for an early scan and is told one sex. “Congratulations! I’m 100% sure!” Lo and behold! At the mid-pregnancy anatomy screen (or later), the penis has magically fallen off and now all the sailboat motif and cute suspenders have to go back. Or vice versa. The question I always get is, “How did this happen???”
Loads of Room for Error
So, just how DID this happen?
Easy. It’s the scanning observer’s opinion, but it’s still just a guess. You assume he or she is experienced in making this determination…maybe, maybe not. Especially when this person displays such confidence in his/her guess, you feel sure that they must be correct in their guess. But it doesn’t mean they are; they can still be very confidently and entirely . . . wrong.
This is why!
External genitalia is just starting to develop later in the first trimester, and it will continue to morph and change in appearance over the next several weeks. All babies have a little something sticking out at 12 Weeks. But if Baby is a girl, that tissue will shrink and become recognized as a clitoris later on, with labia seen on each side. If a boy, this part grows a little larger and becomes a penis. The scrotal sac develops over the next few weeks but is still quite small. And we cannot see testicles until somewhere around 28 Weeks (or maybe slightly earlier).
The Nub Theory
Most readers ask if this test has any validity. The answer is “some.” If (and, again, subjectivity comes into play here), if an observer knows what fetal angle to obtain and how to read the angle of the nub, you might have a 70% accurate guess. But that’s a few IFs. The observer also has to know when the angle is equivocal, meaning the protruding part is not one way or the other but somewhere in-between. In these cases, a guess cannot be made. Keep in mind here that even if the angle is perfect, there is still a ~30% chance of an incorrect guess! In other words, it’s not a hugely reliable predictor.
So, What’s the Best Advice?
Later is better! Wait for your mid-pregnancy anatomy screen at 18 – 20 Weeks. Below are great images of typical and normal-appearing external genitalia of each sex at this age:
If Baby isn’t cooperating, don’t put the heat on your sonographer to guess anyway. Part of a good sonographer’s job is also to know when NOT to guess.
The truth is that no one should be providing a guess for sex determination much earlier than this in pregnancy, especially for a fee. And certainly not with a 100% positivity attached.
Just because someone says she is 100% sure, doesn’t mean she is right.
Business is business. As long as parents will pay for it, someone will take your money and offer a guess. This is the unfortunate bottom line in the non-medical ultrasound business. I’m not saying you shouldn’t go to one of these places. Maybe you just want to see a heartbeat and bond. This is understandable. But I caution you to pay for fetal sex determination earlier than 18 Weeks.
Advice Regarding Early Fetal Sex Determination
All you moms who are thinking about paying for an early scan at a strip mall near you (or anywhere!), please first consider the above info. It might just save you a few bucks and some disappointment later. Alternatively, if you are the kind of person who can remain entirely neutral about any sex guess and just want to have some fun watching Baby move, go for it. Have a blast.
The biggest issue here is our own nagging, relentless, compelling need to know as soon as possible. But more of the same will keep happening. Businesses won’t quit selling early fetal sex determination as long as pregnant moms are buying. Let’s pass the word around, ladies. Just don’t buy what they’re selling!
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