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What to Expect at Your 15-Week Ultrasound

last year6 min read
Last updated: Jan 20 2023

Curious about what to expect at a 15-week ultrasound? We’ve got you covered. Read on to discover why they’re done and what they reveal.

15-Week Ultrasound

An ultrasound exam uses sound waves to create an image of what’s happening inside your body.











This medical test is used to monitor the health and development of your growing baby during pregnancy and diagnose and manage certain medical conditions.

The image that an ultrasound exam produces is called a sonogram.

There are various reasons why you may have a 15-week ultrasound.

We’ll take you through the details.

First up, let’s look at where you’re at when you’re 15 weeks pregnant.

In this article: 📝

  • Is 15 weeks considered 4 months pregnant?
  • Can you get a sonogram at 15 weeks?
  • What you can expect from a 15-week ultrasound exam
  • What a baby looks like at 15 weeks in the womb
  • Can you tell gender at 15 weeks ultrasound?

Is 15 weeks considered 4 months pregnant?

At 15 weeks, you’re in Month 4 of your pregnancy.

That means you’re at the beginning of your second trimester. 🎉

*Counting pregnancy weeks can be a tricky business.

Day 1 is the first day of your last period.

And, yep, technically, you’re not actually pregnant at that point.

In fact, conception will only take place about two weeks after that, when you ovulate.

Click here for more info on the entire pregnancy timeline.*

Can you get a sonogram at 15 weeks?

According to the American College of Obstetricians and Gynecologists (ACOG), you’ll have at least one standard ultrasound exam while you’re pregnant.

And it usually happens between 18 and 22 weeks — a little later than the 15-week mark.

This second-trimester ultrasound is called an anatomy scan and helps identify health conditions that could affect your baby’s brain, heart, bones, or organs.

Waiting until 18 weeks to do an ultrasound means that it’s more likely that you’ll be able to see the limbs and organs clearly.

But there are reasons why you may have an ultrasound at an earlier stage.

You may want to screen for genetic differences or check the fetus’s heartbeat.

An ultrasound in the first trimester can also be used to look for an ectopic pregnancy, check gestational age, and see if there’s more than one little peanut swimming around in there.

And there are also reasons why you may have an ultrasound later in your pregnancy.

In the third trimester, an ultrasound might be used to monitor fetal movement, check the location of the placenta and the volume of amniotic fluid, and see if everything’s going okay in there for both you and your baby.

What you can expect from a 15-week ultrasound exam

There are two types of ultrasound procedures that you can have — transvaginal and transabdominal.

Both involve an instrument called a transducer.

This device produces sound waves that bounce around your body and create echoes that are then transformed into an image.

Yep, pretty amazing stuff!

For a transabdominal ultrasound, a gel will be put on your belly, and the transducer will be moved over the area to produce the image.

A transvaginal ultrasound is done by inserting the transducer inside your vagina.

If you have an ultrasound very early on in your pregnancy — sometimes referred to as a dating ultrasound — it’s likely it will be done with this method.

A transvaginal ultrasound can confirm that you’re pregnant (and how far along you are), measure the fetus, and look for multiples.

For a standard ultrasound, you can usually see most of what you need to see from a 2D version (basically, a flat image).

So what about 15-week ultrasound 3D or 4D options?

Here’s what to know.

A 3D ultrasound provides a bunch of 2D images taken from various angles.

These are then puzzled together to create a 3D picture.

A 4D ultrasound goes one step further and is able to show movement.

While a 2D ultrasound is usually all you’ll need, a 3D ultrasound can help diagnose physical differences early on — so it may be offered to you if your healthcare team thinks it’s worth having a more detailed look.

You may have heard that 3D and 4D ultrasounds offered by private companies can give you a great keepsake of your baby’s time on the inside.

But there are reasons to be cautious here.

While there is no evidence that ultrasounds harm you or your baby, there’s a small chance that too many elective ultrasounds could negatively affect you or your child in the future.

So it’s recommended that ultrasounds only be done by medical professionals for medical reasons.

What a baby looks like at 15 weeks in the womb

If you do get a 15-week ultrasound, what can you expect to find?

At 15 weeks, your little fetus is around the length of a pear — about 4 inches.

By this stage, their arms, legs, hands, feet, fingers, and toes are all on the map.

And their organs are all formed.

Eyebrows, eyelashes, and nails are starting to make an appearance.

And they’ll also be covered in a fine air called lanugo that keeps them warm and protected.

Can you tell gender at 15 weeks ultrasound?

Before we get into the question of 15-week ultrasound gender accuracy, let’s do a recap on some terminology.

While sex refers to someone’s physical characteristics, gender is how a person identifies and expresses themself.

So at a 15-week ultrasound, there’s really no way of telling a baby’s gender.

But there is a chance that you may get a sneak peek of the sex they will be assigned at birth.

At around 14 or 15 weeks, genitals become more clearly differentiated, meaning the question of whether you’re having a boy or girl could be answered as early as this.

Second and third-trimester ultrasounds are amazingly accurate at predicting sex.

According to this study, they get it right 100% of the time.

A first-trimester ultrasound is substantially less accurate — getting it right about 75% of the time.

##15-week ultrasound — the bottom line
While 15 weeks is slightly early for a standard second-trimester ultrasound (AKA an anatomy scan), there are reasons why you may have one at this point.

These could include checking how long you’ve been pregnant and assessing any risks to you or your baby’s health.

While getting a 3D or 4D scan as a keepsake can be tempting, it’s best to stick to using this technology only when medically necessary.

Exciting times ahead!

If you’d like to connect to a community of people who are in the same boat as you, join us on Peanut.

We’re having the conversation. ❤️

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