The Anatomy Screen

What’s the anatomy screen?

Better known to many as “the scan where I can tell the gender!” Many of you moms out there may already know determining boy or girl is not the purpose of the scan but rather a sometimes side-perk. This post is dedicated to the routine or Level 1 anatomy screen and what we look to document on it.

When Is It Performed?

The anatomy scan is routinely ordered by your doctor to be performed between approximately 18 – 20 Weeks of pregnancy. We can perform this scan a little later as long as your doc gives the okay but, typically, not earlier. Those who are antsy to find out their baby’s gender will usually ask to have the anatomy screen earlier, but your doc will likely not sign off on that one. The reason for waiting is that Baby and his/her organs need to be large enough to be able to evaluate them well. We already prepare ourselves to battle Baby’s position. Along with the other limitations of ultrasound, scanning too early just adds another and defeats the purpose. And if Mom has extra weight around the middle, the screen will sometimes be pushed back a little further. We can see a little better with a little bigger baby.

What’s the Purpose?

This exam is ordered to rule out structural malformations on Baby. We want to ensure that all Baby’s parts exist where we expect them and are functioning properly. Diagnosing serious problems in advance is the real purpose of ultrasound. Physicians can then prepare a plan for management for mother and baby and assist in providing the parents and family all the education and counseling needed.

Even if you elected to have genetic testing early on, it can’t detect some abnormalities, like a heart problem, for example. Additionally, some chromosomal problems are not obvious on ultrasound. Unfortunately, no test can detect every problem which is why you are offered different types of testing.

If your pregnancy is high-risk to start or if a problem is detected, your doctor may elect to send you to MFM (Maternal Fetal Medicine) for a Level II anatomy screen. This just means the sonographer evaluates a few more structures and takes a few extra measurements. The perinatologist, or high-risk OB doc, reads the scan and forwards a report to your general OB doc.

It’s true that we may detect findings which require follow-up and end up resulting in no problem. Thank goodness! You may feel like you ended up worrying for nothing. However, if a serious problem was found, you’d probably be happy you knew about it in advance. Special circumstances require life-saving surgery for Baby immediately after birth or require special NICU accommodations that your local hospital may not offer.

True story!

My co-worker and partner in crime in ultrasound (of all people!) discovered her child had a heart condition, a very rare one at that. Instead of four chambers, he had two. She had innumerable tests prior to delivery by MFM and a perinatal cardiologist. They needed to make every effort to determine the extent of his problem before he was born. Even though one of our local hospitals had a NICU, it wasn’t equipped to manage his severe heart defect. Moreover, she could not deliver him vaginally because it put too much stress on his heart. She had to deliver him out of state, and he required surgery immediately after birth. He did great! Thanks to the incredible and extensive knowledge of some very dedicated neonatal cardiologists!

Do I Have to Have It?

Absolutely not. As a patient, you have the right to decline any test. I’ll advise, however, that you discuss this option with your healthcare provider first. You need to communicate with your physician the reasons for your decision so that she/he can counsel you on what declining means for you and Baby. Your doc will also want the opportunity to clear up any misconceptions you might have about the technology.

If one of your reasons is because you believe ultrasound is radiation, you’re in luck!

Ultrasound is not radiation!

You can click on the link above to read more details about this factual bit of ultrasound info. In fact, please do!

What Things Do You Document?

We have a long list of structures to document on your anatomy screen. Some of the things we look for on this scan are as follows:

Cervical length–we measure the length of your cervix.

Placenta–we evaluate its shape and features and tell your doctor where it is located.

Amniotic fluid–we tell your doctor if the general amount of your fluid is normal.

We measure your baby as shown below. However, please note the images were all taken at different gestational ages!

The head from side to side (BPD or biparietal diameter) and around (the HC or head circumference):

BPD, HC, anatomy screen

We measure around the belly (the AC or abdominal circumference):

AC, anatomy screen

Another image of the fetal abdomen is seen below without the measurement:

fetal abdomen, anatomy screen

 

And the femur length (FL):

FL, anatomy screen, femur length

 

These measurements estimate a weight which is usually about 8 ozs. at about 18 Weeks.

We document internal organs and other structures:

Parts of the brain, orbital lenses, facial structures like a nasal bone, upper and lower extremities, heart (very basic views), spine, stomach, kidneys, bladder, umbilical cord insertion, and umbilical vessels.

After we take all these images, we formulate a report for your doctor in great detail regarding the above parts. We also document what structures could not be well seen. Usually, if your baby doesn’t cooperate to allow us to see everything we’d like, your doctor may or may not send you back for a follow-up scan at some point to attempt a recheck.

How Do I Get Results?

Only your doctor (or MFM doc) can give you results! Never, never, never the sonographer. For those of you who have had the terrible experience of a problem on your anatomy screen, you have a hundred questions and your doctor is the only one who can answer them for you properly. Your doctor is the one with whom you have the important relationship. He/she manages your pregnancy, not your sonographer. You can read more about your results here.

So, What About Gender?

Most facilities, as a side perk, will allow your sonographer to give you this information if she determines that it’s possible. Unless we see a problem where gender plays a role, boy or girl is not important to the health of your fetus, and your doctor doesn’t really need this information. We know, however, that it is important to those of you who want to know. And there is nothing wrong with wanting to know! There is also nothing wrong with waiting to find out, and that decision is as personal as picking out a name.  Believe me, I couldn’t wait to find out myself. Yes! I scanned myself! A perk of the career;)

A little side note here … many facilities are beginning to put restrictions on gender determination. As more and more legal cases pop up over wrong gender guesses, facilities will take more precautions to limit their liability. And if you decide to visit a non-medical ultrasound facility for a fun scan, please read more about them in the link provided and ensure your sonographer is properly educated! (No, they don’t have to hire real sonographer!)

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We love a fun family! And we can’t deliver your little sweat pea, but this is one priceless piece of info we SO enjoy delivering when we can! It’s a big job which requires time, focus, and concentration. For some guidelines on how many to include in your entourage for this exam, click this link for a little insight into a sonographer’s recommendations!

It’s okay to want to know gender, to keep it a mystery, or to even have a preference. It’s just not okay when that’s all that matters.

Questions? Great! Email me, and I’ll answer what I can!

 

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