Having experienced five pregnancies and always being an avid reader to keep up on the latest regarding pregnancy, I was surprised to learn that I had never heard of Amniotic Band Syndrome until reading the Nicholas Sparks novel At First Sight. After reading this novel, I decided to learn more about this condition. Amniotic Band Syndrome is a congenital disorder in which body parts of a developing fetus become entrapped by fibrous amniotic bands while in utero. It is not thought to be genetic or hereditary, but simply an accidental event that occurs in about one of every 1,200 live births.
I used to attend school years ago with someone who had this condition, causing most of the fingers on one hand to be badly misshapen and underdeveloped. I never really put two and two together until reading Sparks’ novel. This child was perfectly formed in every way except for the affected digits.
The body parts usually affected by amniotic band syndrome are the limbs and digits. However, this does not account for over about 50 percent of cases of ABS that also have another congenital abnormality such as cleft lip, cleft palate or clubfoot. Eighty percent of cases involve hands or fingers.
No one really knows the actual cause for ABS, but it is theorized that a partial rupture occurs in the amniotic sac at some point during pregnancy, allowing fibrous bands to float in the amniotic fluid, which could encircle and trap some part of the developing fetus. The fibrous band would not continue to grow, however, the developing baby would. This could allow the band to become constricting and block the flow of blood to the affected limb or digit. This can result in a naturally occurring amputation of limb or digit, or cause the limbs to become necrotic or “dead,” requiring surgical amputation. Think of it as a string wrapped around a finger that becomes too tight and cuts off the circulation.
Even though most pregnant women receive routine sonograms during pregnancy, these fibrous strands, or amniotic bands, are difficult to detect through ultrasound. Most cases of ABS diagnosed through ultrasound are discovered indirectly due to a swollen or constricted limb of the fetus. The good news is that ABS is very rare.
Since no true cause is known, there are no known preventive measures to avoid ABS. Prognosis depends greatly upon the location and severity. In rare instances of ABS, a surgeon may elect to operate in utero. More often, plastic surgery or reconstructive operative procedures are done on the affected infant after birth.