What is Amniotic Band Syndrome?

QUESTION

Dear Ms Ultrasound,
I had an ultrasound just this week at 19 weeks. The results all came back fine -- no baby abnormalities -- which is great. There was something yet to be determined; there was a little "thing" which the doctor said could either have been another baby that didn't form or a small amniotic band. They reassured me yesterday that the baby was fine and that this wouldn't affect the baby. But then why when I look on the Internet it says that the bands cause abnormalities. What should I think?

Kara

ANSWER

Hi Kara,
First off, your ultrasound did not find any fetal abnormalities. That's great! From the sounds of your explanation, your doctor is not too worried about the findings.

Usually with a real amniotic band, there is NO question. You can see the band floating around in the amniotic fluid. The area they saw on the ultrasound makes me think it was small because they thought it may have been a twin. Sometimes you may instead have what is called a venous lake (an area in the placenta which is not a problem) On occasion this may be mistaken for a twin sac that didn't make it or an amniotic band. These are a few scenarios this finding might be.

Looking up amniotic band syndrome on the Internet would certainly scare anyone. There can be many abnormalities from an amniotic band syndrome. Know that they are not common and not hereditary. Something like 1 in 1200 live births have an amniotic band syndrome.

Because the ultrasound showed a normal fetus, there is a less likely chance, even if it was an amniotic band for developmental problems. The severe problems commonly occur in the first trimester.

I would imagine your doctor will do a follow-up ultrasound just to keep a check on that area. At my facility, if we really thought we saw an amniotic band we would have the patient have an ultrasound and consult with our perinatalogist.

I think you can relax since all looked fine with your baby. Ask your doctor on your next visit how concerned she/he is and when you will be having a follow up. If your doctor says you don't need a follow up you can really relax because a true amniotic band is followed closely.

In the meantime I hope you can put this aside and concentrate on having a wonderful worry-free pregnancy!

-- Jane, RDMS

Jane Foley

Jane Foley has worked as a Sonographer (Ultrasound Technologist) since 1979. Jane has lived and worked in many parts of the world including Saudi Arabia. She is a Registered Diagnostic Medical Sonographer or RDMS. She pulls a wealth of information from her experience in the field of Radiology and her interactions with such a broad cross-section of cultures she has visited. She now makes her home on the island of Maui with her English husband, Michael.