Abnormal first-trimester fetal nuchal translucency and amniotic band syndrome.

We report a case of amniotic band syndrome diagnosed prenatally by serial sonographic examinations. Our initial sonographic image showed a large fetal nuchal translucency (NT) at 12 weeks' gestation. Repeated fetal ultrasound images revealed an amniotic band and right upper limb anomaly. Fetal MRI at 19 weeks' gestation revealed right forearm hypoplasia and pseudosyndactyly. The fetus was prenatally diagnosed with amniotic band syndrome and was suspected of having severe functional impairment of the deformed limb. The parents decided to terminate the pregnancy at 21 weeks' gestation. In fetuses with aneuploidy and various structural and genetic abnormalities, the NT thickness is increased in the first trimester. As far as we are aware, this is the first case report of increased NT and limb anomaly associated with amniotic band syndrome. In chromosomally normal fetuses with increased NT, intensive sonographic follow-up should provide grounds for a precise antenatal diagnosis.