Concordant body stalk anomaly in a monoamniotic twin pregnancy at 9 weeks.

Abstract

gestational weeks. She had anunremarkable medical history and reported no consanguinity.Sonographic examination performed with Philips iU-22ultrasound system using a C10-3v multi-frequency curved arraytransvaginal transducer (Philips, Bothell, WA, USA) revealed amonochorionic monoamniotic twin pregnancy: the gestationalsac contained two live embryos with a crown–rump length of29mm, and no dividing membrane could be identified; a singleyolk sac was identified. Both embryos had a large abdominalwall defect, partial evisceration of abdominal contents andheart, and were connected to the placenta by a short umbilicalcord. Lower limbs were not identified in one fetus and grosslyabnormal in the other; the latter also had a cystic structure atthe caudal pole (Figure 1). The lower part of the body of bothembryos was visualized within the extraembryonic coelom,outside of an apparently intact amniotic membrane. Aftergenetic counseling, estimation of the recurrence risk andexplanation of the severe prognosis, the woman requestedtermination of the pregnancy while refusing fetal karyotyping.A detailed pathological examination of the embryos was notpossible as the specimen obtained after surgical terminationwas severely disrupted.Data on first trimester diagnosis of body stalk anomaly arelimited. In a series of 106,727 nuchal translucency scansperformed at 10–14weeks, 14 fetuses with body stalk anomalywere found.