Ultrasound Gender Determination

Ultrasound Gender Determination ~
Pink or Blue?


Ultrasound gender determination can be tricky! Especially too early in pregnancy. Or any time they just won’t cooperate!

gender determination

Female Gender 16 Weeks

male gender, 16 Weeks pregnant

Male Gender 16 Weeks


How many times have all you moms out there, young and old, heard the story that goes, “They told her it was a ‘this,’ and they decorated an entire nursery, and it came out a ‘that’! Those ultrasounds are wrong sometimes, ya know!”

A dollar for every one of those comments would buy me my dream cottage on the Amalfi coast! However, I understand why this happens, and sonographers everywhere need to apply more discretion. First of all, you may already know that it’s not the machine that’s wrong. The sonographer or observer scanning you evaluates what she (or he) sees and determines Baby’s sex. The whole process is entirely subjective! And inexperience sometimes causes sonographers to excitedly guess or, otherwise, cave to the pressure from anxious parents. Unfortunately, sometimes guess incorrectly.

Advice Regarding Gender Determination for the New Sonographer

First rule of thumb for any newbie sonographer out there…don’t guess! Don’t put a percentage on your guess, and don’t say “I think.” Also, don’t say “It kinda looks like ‘this,’ but let’s wait until next time.” Parents may want you to guess, but they also want you to be right! Just a word of caution here – some patients may become upset with you if you don’t guess. But if you’ve exhausted your bag of tricks and you still are not sure of what you are seeing, you owe it to the patient to explain this. It’s something you have no control to change, and you would rather they not become attached to the wrong sex. Hopefully, they will understand!

Psychologically and emotionally speaking, most parents start to really become attached to one sex or the other. They begin to envision the first dance recital or baseball game by the time the next ultrasound exam rolls around. On more than a few occasions in my career, someone else guessed incorrectly (usually, too early!), and I had to be the bearer of bad news. After witnessing the affects of “mistaken identity” (shock, anger, tears, sadness, guilt), I adopted a personal policy long ago to only offer a guess when parts were obvious. In other words, Baby had to be in a great position to easily see a penis and scrotum or labia/clitoris. Even though my policy upset a number of my patients in the past, I truly believe refraining from tossing out any old guess is in their best interest and can save them some heartache later.

True Story!

One grandmother, so excited by the doctor’s early guess, flew right out and bought thirty-two dresses! Yep, 32. She did so despite the doc’s warning about his level of confidence and told her to wait for the sonogram with me. Fortunately, he got lucky with his baby girl guess, and grandma was a very happy woman (and a little less rich)! However, you can imagine the disappointment in returning all those frilly frocks if doc was wrong. I always hated giving such news!

Please, all you excited moms-to-be, remember your sonographer doesn’t withhold information about fetal sex just because! We’d actually really rather all our babies cooperate quickly and easily! It’s such a bummer for us both when they won’t. You can’t plan all the fun things you imagined you could. Shopping, party planning… And believe me, I always preferred when my patients left my room hugging me instead of cursing my existence. A magic trick to make Baby flip on command? It’s too bad we aren’t bestowed with super powers upon certification!


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Male Gender on Ultrasound

How many times has a sonographer pointed out gender to all you readers out there during your sonogram and you respond back with a “Huh, where?” Even male gender on ultrasound can be difficult to discern if other parts are in the way.

Check out this recent email from a mom who had the same problem:

confused mama: Hello! I just recently went in for a gender ultrasound which I was so excited to finally get. I had an uncomfortable experience with the ultrasound technician. The second she saw the baby she said I am 100% it is a boy. She didn’t show me, my mom, or my mother in law the penis or scrotum and she didn’t explain at all. I was 19 weeks and 2 days at the time of this ultrasound. I might be in denial it is a boy but I honestly am confused by the photo she gave that shows the penis and scrotum. I am confused because there are two lines underneath it but in all the boy ultrasounds I have seen, the penis and scrotum look more defined and those two lines aren’t there. It might be the butt, I’m thinking, but I don’t know. Can you please give your professional opinion? I had a friend who is also a RDMS and she said she could not tell the gender. I am debating if I should do another gender ultrasound. Please help.

outside image

wwavb: Okay, so check out the image below.


You are seeing an underneath view of Baby. Encircled in yellow is the cord which is running between Baby’s legs and obscuring parts a little. You should be able to see boy parts a little better with my annotations.

I wouldn’t go for another, especially if it’s one of those ultrasound drive-thru cash cows. Does your friend not do OB/GYN? I felt it was pretty easy to tell, but I would have either not given this image to a patient or otherwise explained the parts.

Glad I could help!
wwavblogger, RDMS


I think some sonographers forget that not everyone can figure this stuff out as easily as we can.  Even if you are an experienced certified sonographer but not in OB, it can still be quite a guess for you, too.  After all, experience is the teacher, right? Experience is also the teacher eventually for ANY sonographer who is brave enough to call anything between the legs 100%. Sorry! Nothing is 100% in any testing arena…even DNA and amniocentesis are only 99+%!

As sonographers, if we’re going to take a penis pic, we should at least narrate for our patients if Baby is feeling a little shy that day.  And patients, if you can’t tell a penis from a big toe, speak up! Most of us are more than happy to show you around! And especially when you pay for a 3D scan, you have the right to see it and have it explained; you paid for it!

Boy vs What??

I’ve posted on this before and I’ll say it again..there are great ultrasound images and there are terrible ones!  Even the best ultrasound professionals can only decipher anatomy from a really good image.  The rest is guesswork at best.  This basic rule of thumb applies to so much of what we do but especially to determining male gender on ultrasound (or female!).

Case in point:

A reader emailed me with a questionable ultrasound image where “Boy” was the guess.  And truly a guess it had to have been judging by that quasi image of boy parts.  On the other hand, the only thing she had to compare it to was the image of her first Baby Boy.  Holy cow!  He was super-duper proud.  Now THAT image is a no-brainer, no-guesswork pic of boystuff, for sure!

confused mama:  Hi! I went in for my Anomaly scan at 18+4 and was given the following ultrasound picture stating that she’s “pretty sure it’s a boy”. I believe the arrow is pointing to the umbilical cord not a penis. But what’s throwing me off is the two very distinguished dots. Correct me if I am wrong but you can’t see testicles at this point in the fetal development on an ultrasound. I feel it’s labia and maybe too swollen to see the clitoris.


My 3.5 year old son’s U/S scan done at 19 weeks looks so different and more recognizable as a boy (the scrotum bulbous and penis) as seen below.


What do you think? Boy or girl???  Thanks in advance for any feedback!!


wwavb: So, 18w4d is a good time for the Anatomy screen but, as you see, being able to see well depends on fetal position and experience of the sonographer among other variables. “Pretty sure” sounds like she’s not been doing this long (I could be wrong, of course) but it’s simply not a great image as opposed to the gender image of your first child. Holy cow! That is a perfect, no-guesses image of boystuff!

There are great images which speak for themselves where all the variables that make a good image line up making the subject very clear. Take a few of those variables out and it’s an image which makes it hard for even professionals to decipher..which is what you have in the first image. No way to really know to what the arrow is pointing and no way to determine the bright dots are girly parts, either. I could have told you if I scanned you real-time but in a single frozen image provided elsewhere, it’s impossible to know. That all being said, it could be a penis; it just may not be a very good image of one.

I’m sorry I couldn’t help you more! If you get other images in the future, I’ll be happy to take another look. Look for your email in my next post!

Best wishes,


What I forgot to add in my email to my reader is that she is correct in that one cannot see testicles in fetal development yet and not until about 27wks or so. Also, labia are not swollen yet as Baby does not develop much fat in the skin prior to about 26wks so no matter the angle, girly parts still look like two or three white dots or lines at this age.  Sometimes, the middle dot (the clitoris) will be higher than the outside ones but labia will look more like a girl later on.

Hope this helps others with ultrasound images that stink.  Thanks, confused mama, for your contribution!

Third Trimester Male Gender

Below is a great image of third trimester male gender, 37wks to be precise.  Even though I do not believe this image requires annotation, I’ve labeled all the parts so as to avoid confusion for some.  Anyone who does not understand this image, should be more concerned with their inability to differentiate between boys and girls.  In other words, this is about as clear as an ultrasound can get.  To further explain, this is a side “turtle shot” as some call it!

One of the testicles can be seen here as a brighter gray and rounded area inside the scrotal sac and the penis, well, it speaks for itself.  He doesn’t really need arrows now, does he??


third trimester male gender, 37wks