What to Expect at Your 7-Week Ultrasound

Not every mama-to-be will have a 7-week ultrasound — you might find that the first ultrasound of your pregnancy isn’t until around 12 weeks.

But a 7-week ultrasound can be a handy way for your healthcare provider to check on the progress of your pregnancy.

Just be aware that what you see on the screen will probably not look very baby-shaped at this point!

In this article: 📝

What is an ultrasound?

Let's start with the essentials.

An ultrasound is carried out by a doctor or trained technician using a hand-held ultrasound wand (also called a “transducer”).

It sends high-frequency sound waves into your uterus, and these then bounce back to show a picture of your baby on the ultrasound screen.

You'll recognize the classic black-and-white image, but at 7 weeks pregnant, it might be hard to even see your little dot of an embryo.

And this could be the first of a few ultrasounds during your pregnancy.

What’s the purpose of an ultrasound at week 7?

There are many different reasons why your healthcare provider might want you to have an ultrasound in week 7 or week 8 of your pregnancy.

Here are some possibilities:

• Dating your pregnancy. A 7-week ultrasound can be used to work out how far through your pregnancy you are, particularly if you’re not sure when your last period was or if you have irregular cycles.
• Checking your reproductive organs (your uterus, ovaries, fallopian tubes, and cervix) for any issues that might cause complications during your pregnancy.
• Checking for multiples. This is especially important if you’ve had any fertility treatment—there could be twins (or more!) hiding in there.
• Looking into pregnancy bleeding. If you’ve had some early pregnancy bleeding, a 7-week ultrasound can help your healthcare provider find out the cause. Sadly, it’s possible that the ultrasound may show if you’ve had a miscarriage.
• Ruling out ectopic pregnancy. An ectopic pregnancy is where a fertilized egg grows outside of the uterine cavity. It’s essential to detect this quickly, as it can be life-threatening without treatment.

Is a 7-week ultrasound internal or external?

Your baby is pretty tiny at this point, so it might not be possible to get a clear picture of them with an external ultrasound.

(That’s where the wand is passed across your abdomen.)

That means your 7-week ultrasound is likely to be internal—with the wand placed inside your vagina (AKA a transvaginal ultrasound).

It may be a little uncomfortable, but it shouldn’t be painful.

Can you see anything on a 7-week ultrasound?

What does a 7-week ultrasound look like?

Well, let’s just say that you probably won’t be able to see anything particularly baby-shaped at this stage.

But here’s what you might spot on the ultrasound screen:

• Gestational sac. That’s the space around the developing embryo, which is filled with fluid. On the screen, it’ll look like a dark oblong, or a circular shape against the whitish background of the inside of your uterus.
• Yolk sac. This is what gives your baby all the nutrients and oxygen they need until the placenta is formed. It looks like a small white bubble inside the gestational sac.
• Fetal pole. That’s what the embryo is called at this very early stage of their development. It looks like a thick whitish area attached to the yolk sac.
  To work out your baby’s age, the ultrasound technician will take some measurements.

At 7 weeks, your baby (the fetal pole) should be about 5 to 9 mm (0.2 to 0.4 inches)—that’s about the size of a blueberry if you’re into fruit comparisons!

And the gestational sac should be about 18 to 24 mm (0.7 to 1 inch).

If the gestational sac is less than 18 mm, that could mean you’re not as far along in your pregnancy as you thought.

But over 24 mm suggests that you’re further along than suspected.

If the technician can’t get a clear enough picture of your baby (they might not be in the right position), you might be asked to come for another ultrasound in a week or two.

Can you see a heartbeat at 7 weeks?

Yes, it's possible!

If everything is progressing as it should with your pregnancy (and your baby isn’t feeling camera-shy), you should be able to see and hear your baby’s heartbeat at 7 weeks.

It’ll look like a slight fluttering or pulsing on the screen.

And it’s beating at about 90 to 110 beats per minute.

How accurate is an ultrasound at 7 weeks?

A first-trimester ultrasound (before 14 weeks) is the most accurate way to work out your baby’s gestational age—and come up with the most accurate due date.

But the estimate could still be out by 5 to 7 days.

Remember: only about 4% of babies are born on their due date!

So at 7 weeks pregnant, you might get a sneak peek at your growing babe, but at this point, they're teeny-tiny, so don't fret if you can't pinpoint them when you look at your sonogram later on.

Your ultrasound technician should be able to help you spot them.

Exciting times, mama!