Healthcare professionals use the 8-week ultrasound to confirm pregnancy and determine a due date. While the fetus is still very small at this stage, the 8-week ultrasound can also confirm a heartbeat.

In the early days of pregnancy, those initial appointments can feel surreal — especially if this is your first pregnancy. Those first appointments are usually designed to get a baseline understanding of your health going into pregnancy and to make sure things are progressing properly.

One major milestone is the 8-week ultrasound. So, why do you have an ultrasound this early into pregnancy, and what can you expect at your 8-week ultrasound? We’ll answer those questions and more.

Even though you can get a positive pregnancy test result 1 to 2 weeks after missing a period, it can be a while until that tiny ball of cells demonstrates physical changes that confirm your pregnancy is progressing. Specifically, a healthcare professional will want to confirm that your fetus has a heartbeat — a clear sign that they’re alive.

In some instances, a heartbeat may be detected as early as 6 weeks, according to Miscarriage UK. If you have a positive pregnancy test, contact a healthcare professional to see if you need to come in for an ultrasound.

A healthcare professional may recommend that you try to maintain a full bladder before an ultrasound, as this can help them view the scan more clearly.

Transvaginal vs. abdominal ultrasounds

When most of us think of ultrasounds, we think of a technician passing a wand over a person’s stomach that’s covered in gel. This is known as an abdominal ultrasound. In most situations, early ultrasounds generally take less than half an hour.

But a transvaginal ultrasound is when a healthcare professional inserts a wand into the vagina. Often, they use this during early pregnancy to get a closer look at the fetus.

Beyond heartbeat, the technician or physician will be able to immediately identify key features such as the gestational sac and your fetus’s crown-rump length. These can help determine gestational age and pinpoint your due date.

This is going to be your first peek at your growing fetus! Don’t expect to see a lot of definition or details this early in the pregnancy.

For now, you’ll see a little figure that looks something like an oblong bean. If there are twins, you might see two figures. The head is still nearly the same size as the rest of the body.

You’ll also see the gestational sac, the fluid-filled space around your fetus(es). Within it, you can also see the yolk sac, which is a bubble-like structure. Depending on the location, you might even get to hear their heartbeat, too.

The main reasons for the 8-week ultrasound may be to confirm a pregnancy, determine a due date, and confirm the baby’s heartbeat. First, your doctor or technician will look for key physical indicators, like a gestational sac and a fetal pole, to verify the pregnancy is in the uterus. This is may be your first indication of twins.

Once they’ve confirmed that you’re pregnant, the next step is to verify your projected due date. Even though you might have initially received a projected due date at an earlier appointment, it’s not always accurate.

Healthcare professionals confirm the initial due date by confirming the first day of your last period, and then adding 9 months and 7 days (or 280 days total). But because not every person’s menstrual cycle is the same length of time, these projections can be off.

With an ultrasound, a physician or technician can determine gestational age and due date by measuring the size of your fetus. The accepted method for early pregnancy dating is the crown-rump length (CRL) measurement because it’s the most accurate (within about 5 to 7 days) in the first trimester.

When you can’t see the baby or a heartbeat

Sometimes you can’t see the fetus or hear a heartbeat — but that doesn’t always mean the worst. Sometimes it means that your calculations on the conception date were off.

If you ovulated and conceived later than you initially assumed, you might be getting an ultrasound too early to get a physical confirmation. In other scenarios, you might have large fibroids or anatomical issues with the uterus that can make screening your uterus more difficult.

But in some situations, it might not be the news you hoped for. Occasionally, the absence of a visible fetus in the uterus could mean you have an ectopic pregnancy, where the embryo implanted outside of the uterine cavity.

Other times, you might have experienced a blighted ovum — when the embryo doesn’t develop or stops developing, yet a gestational sac remains. Or, you might have experienced a miscarriage.

Your doctor will be able to give you insights into what is happening in your specific instance and when, if desired, you can try for another pregnancy.

The first trimester is a busy time for your fetus. This is when all of the core building blocks of their body are being developed.

At 8 weeks, your fetus is about the size of a kidney bean and could be around 1.6 centimeters (cm) long, according to the United Kingdom’s National Health Service (NHS). While they still don’t look like a baby, they look more human and less otherworldly.

Now they have arm and leg buds, and although they’re webbed, they have fingers and toes. Other essential bodily infrastructure — like bones, muscles, and skin — are also developing, but their skin is still see-through at this point. They’re a busy little thing that’s constantly moving right now!

The first trimester can be a rollercoaster, and not just because of excitement and other emotions. The first trimester can cause some rough symptoms, and around 8 weeks is when they can intensify. Common symptoms include:

When you first know you’re pregnant (via a pregnancy test), you should contact a healthcare professional to see when you should come in for an evaluation and ultrasound. This is often done to confirm the pregnancy, verify your expected due date, and ensure that your baby — or babies — has a healthy heartbeat.

Your 8-week appointment may include a transvaginal or abdominal ultrasound, which is low risk but can offer the first glimpse at your baby. However, it’s important to know that when it’s this early in the pregnancy, you might not be able to identify a heartbeat or see your fetus just yet.