Director of Maternal- Fetal Medicine, Maine Medical Center, Portland ME,
Professor of OB-Gyn, University of Vermont School of Medicine.

This is a case of mistaken identity. At 12 weeks this fetus was erroneously diagnosed as a gastroschisis which turned out to be (at 16 weeks) a monoamniotic twins with an acardiac twin sitting atop its normal twin!

The patient is currently at 28 weeks of gestation. The acardiac fetus continues to grow and is about 60% of the size of the normal twin.