Amniotic Bands

Jane Foley's picture


Dear Ms. Ultrasound,

I had my first scheduled ultrasound today at 16 wks. Everything else checked out fine...but I was told by the radiologist that I never formed an amniotic sac. I have amniotic bands instead. He told me it was something that needs to be monitored because as the baby grows, the bands can stretch and snap or the baby's limbs can become entangled.

I can't really find much information about this on the web and I was wondering how this could have happened and what happens if a band snaps? I read that a similar condition to amniotic bands could occur after a D&C. I had a D&C plus laproscopy about a month before I became pregnant. Could this have caused it?

I was already told in an ER last month that I have some bleeding underneath where the baby is attached, and I am just worried about more complications. Is this really serious? Because the radiologist today acted like it wasn't too much to worry about?

Thank you,



Hello MomSki

Amniotic Band Syndrome is when the amnion (a layer of the gestational sac) ruptures, usually in the first trimester. The result is a band that extends from the edge of the chorion (another layer of the gestational sac) to the fetus. The statistics show that this occurs approximately 1 out of 1200 live births.

Once an amniotic band is discovered, a thorough investigation of the fetus, it's limbs, digits, face, and abdomen must happen. The greatest fear is not about the band rupturing, but about the baby getting a part of his/her anatomy entangled.

It seems that the ultrasound did not show any fetal involvement. This is great! You will be closely monitored as the pregnancy progresses. Each time, the limbs should be looked at closely as this is the most common body part to become involved.

The prognosis varies with the specific types of bands,(meaning how many, the length, where it is attached and how early the rupture occurred). The earlier in the pregnancy the ruptured occurred the worse the prognosis. The bleeding the radiologist saw, sounds like a subchorionic bleed. This is were there is some bleeding under the chorion. It all may be involved with the initial rupture that produced the amniotic band.

A subchorionic bleed is not uncommon and usually resolves itself as the pregnancy progresses.

As a mommy to be, there is not a lot you can do, so don't put too much energy or worry into this finding. I always like to suggest that each day you take a minute to visualize the baby staying well away from the amniotic bands. This is the most effort I feel you should put into this finding. Stay current with your doctor and your follow up ultrasounds.

With Regards,
-- Jane RDMS