Boy Ultrasound With Three Lines? [Confusion Solved]

Ultrasounds are pretty exciting events. You sharing a cute moment with your partner. Finding out how close you are to having your baby. And there’s also the thrill of finding out the baby’s gender. All of this sounds amazing. But what if an unforeseen event shows up, something like three lines with the baby boy’s ultrasound? How do you interpret that?

What doctors are really looking for in an ultrasound is signs of physical genitalia. So when it is a baby boy, the doctors are able to spot male testicles, a penis, and a scrotum as early as the second trimester. Three white lines are usually the sign of the female clitoris and labia in the middle that can resemble a hamburger with two buns and meat in the middle.

What Are Three Lines On An Ultrasound?

The ultrasounds intend to get all the details necessary to make new parents prepared to welcome their baby. It not only keeps track of the baby’s health but also reveals the gender and any abnormalities that should be addressed before or after the birth. In short, ultrasounds are a baby’s amazing development track that allows you a sneak peek into what you are going to have.

Speaking for what you are about to have has a lot to do with how the genitals are shown in the potty shot. The 3 lines in the gender scans are usually a telltale sign that you are going to have a girl. But that is not definite. If your baby boy’s legs aren’t apart and the genitalia has been wrapped due to a number of reasons, you might be able to see three white lines.

What Does a Female Gender Look Like On An Ultrasound?

Sonographers look for different signs to determine the baby’s gender if it is a girl. They are mainly looking for genitalia, which in the case of a girl, appears as a hamburger with a middle line parting. If the sonographers are trying to determine the sex of the baby before the 20-week scan, then most probably the girls’ image is not accurate, and the results are also inaccurate.

But when the pregnancy has matured to a point where everything is crystal clear, using the three lines method is accurate to determine the sex of the baby.

What Does A Male Gender Look Like On An Ultrasound?

There are plenty of signs in a gender scan that hint toward a baby boy. All you need is a competent ultrasound technician to decipher those signs. While talking of baby boy ultrasounds, your technician might notice the tip of a penis behind the testicles. It is harder to see, but if your fetus has matured, the sign will be clearer. This is known as the turtle sign and depends upon your baby’s angle of lying and gestational age.

Boy parts, meaning the male genitalia, are easier to identify if your little boy has an erection. As surprising as it sounds, a baby boy can have erections, which are helpful in pinpointing gender. An erect penis is easier to identify and, therefore, a clear indication of the male gender. However, it should be noted that having erections that early is completely natural and nothing to be worried about.

Is The Three Lines Method Reliable?

You cannot completely rely on the three lines method. The position of your baby and opening or closing of his legs tend to shade the genital area making it hard to determine if you are having a girl or a boy until and unless your doctor has a good look at the genitalia. You cannot even completely rely on early scans, as the baby tends to move around and grow to alter the way it appears on the scan.

So whatever you do, just don’t get your hopes too high, as what might appear as a clitoris may be a protruding penis. In the second trimester, even with all the technology at hand, the baby’s sex remains a mystery if he is in a position that is inaccessible to the sonographer.

Pregnancy is unpredictable. You can bet you are having a girl with signs from the ultrasound, but that is only a factual guess. While it is a tried and tested method, still nothing can be said for sure until the pregnancy has matured after a certain point and the baby is in the right position for inspection of genitalia.

What Is The Right Time To See Three Lines On An Ultrasound?

What Is The Right Time To See Three Lines On An Ultrasound?

As mentioned repeatedly, there is no better time to see three lines of a girl’s gender than a 20-week anatomy scan. The ultrasound uses sound waves to determine the sex of the baby as it reaches the internal body and discovers the genitalia. Between the 16th to 20th weeks, you will see marked changes in ultrasounds.

It all depends mainly on the position of the fetus. If your baby is in breach position, you will not be able to see the genitalia be it a three-line mark or a penis. But if that is not the case, doctors use three lines method as early as the sixteenth week of pregnancy as the lines start becoming visible at that time.

The accuracy is questioned, but some doctors say that due to the lack of fat or muscle in the baby at that age, the lines are more clear, and the scan becomes accurate. As time passes, the fat starts to accumulate on the baby’s labia, and it swells up, making it difficult to determine if it is a girl or boy if the boy’s testicles are squeezed together with closed legs. Both will give the same look. So some doctors consider this method to be more effective earlier than later.

20-Week Scan

A 20-week scan is a normal prenatal scan that occurs at the 20th week of pregnancy to monitor the physical development of the fetus and to discover if there is any abnormality in the fetus that can later prove harmful. The sonographer takes 2D to 4D images from inside your uterus and takes all kinds of measurements to ensure the health and proper growth of the fetus.

You can also find out about the baby’s gender with this scan. The external genitalia is fully formed by this point and the scan can determine the sex. However, some changes can also occur in determining the gender accurately if your baby’s genitalia is in an inaccessible position. If the fetus does not gives access to the genitalia, the unclear image is inaccurate about the sex of the baby. In such a case, doctors tell you if they are not sure.


The process of a 20-week scan is much like any normal scan. The doctors make you lie on the exam table, placing ultrasonic gel on your belly. After that, the sonographer will move an ultrasound wand on your belly, reaching your abdomen. The process is marked with taking measurements of the fetus, determining any abnormalities, and taking pictures.

The measurements are not just for the size of the fetus but also for organs inside the baby, which are closely inspected by freezing the monitor screen. In addition to this, the doctors also draw lines on the screen to determine the size of the arms and legs and to be sure that everything is normal and in accordance with the gestational age of the fetus.

You may also be asked to cooperate if the fetus is not in the right position to take all the measurements. This may include drinking something sweet or moving around a bit till the fetus moves and becomes accessible for inspection.

Your doctor will go over the results of the scan and let you know if anything is not right. They will have a follow-up plan with you as well if needed. Once your doctor is completely satisfied with the results of your scan, he will ask you to wipe the gel and leave with the pictures and the exciting knowledge of what you are going to have.

Are The Three Lines Always Visible?

The three lines will not necessarily be visible all the time. If you are having a baby boy and he is at the perfect angle for a gender scan, the doctors will see his male genitalia instead of the clitoris, which makes the three lines.

According to healthcare specialists, it is not possible that three lines are always explicitly seen in the ultrasound. This is mainly because of your baby’s position. They keep on moving in the womb. But when the lines are completely visible, then it is a great way to determine gender.

You should also keep in mind that the line may not even be visible to you but only to your sonographer, and that too after a certain time period. They will also be more likely present when you are having a girl. Boys are easier to pinpoint due to erect penises, but always try to look carefully between the legs of the baby to see what you are going to have.

Can A Baby Boy’s Ultrasound Show Three Lines?

Yes, most likely. A baby boy’s ultrasound can show three lines if his legs are closed and are at such an angle that his penis is completely hidden from view. So it is a rather common misconception that only girls have three lines on the ultrasound.

Ultrasounds are nothing but a combination of sound waves that are horizontal lines focusing on the angles of your baby. Doctors fail to communicate to new parents that three lines can appear when having a gender scan of a baby boy. However, due to changes in the baby’s orientation, the image may appear as lines hiding the penis and making it harder for the sonographers to determine the sex.

Genitals also appear as lines because the ultrasound is also in the form of sound waves and horizontal lines. So there is no definite way of separating three lines from the gender scan of a baby girl or baby boy.

What Does It Mean If A Baby Boy’s Ultrasound Shows Three Lines?

It just means that the baby boy is at an angle where his penis is barred from view. If the first ultrasound after the pregnancy has matured shows a boy, then you are having a boy, and this is only happening because the fetus keeps on rotating inside the womb. It does not mean that your baby boy has somehow miraculously changed into a girl.

Your suspicions will be further answered when you have a 20-week scan. However, you can use a few hints to differentiate between three lines from a baby boy’s scan. You need to focus on the thigh bone or femur in this case. If the baby is a boy, the genitals will be lower and protruding from below the femur. In this case, the middle line will appear longer than the other two lines on the sides.

In case the middle line is in an inverted position, you are having a baby girl. If the scrotum comes into the image, then it is out of the question that you are having a boy. Another way to identify the three lines for a boy is by looking at the bladder. The bladder will be visible in a boy’s gender scan as male bladders are lower in position and on top of the abdomen, making them clear.

Wrapping Up

It is clear that three lines method is a very common misconception that does not exactly say if you are having a girl. Still, it is often used, and when the pregnancy has matured, the baby is at a right angle, and there is absolutely no sign of a penis on the baby, you can safely bet that you are having a baby girl.

The three lines can be seen in a baby boy’s potty shot, but they will appear differently than in a girl’s gender scan. A well-trained sonographer will definitely see the difference and let you know the gender of the baby. This method is only reliable if the sonographer is sure at the 20-week anatomy scan.

However, doctors start judging and using this method at 16 weeks of pregnancy. Before that, it is just not that reliable to use and can be impacted if your baby boy’s legs are not completely apart to expose the genitalia. If the genitalia is hidden due to any number of reasons, even after 20 weeks, as a breach position is likely, it is not possible to accurately predict the gender of the baby.

Stephanie Edenburgh

I'm Steph, a mom to 3 beautiful children and lover all things having to do with my family and being a mom. I've learned a lot raising my own children and working in education and healthcare roles throughout my career. Living in beautiful Southern California I enjoy documenting and writing about all of the hard work us mom's do on a daily basis.

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