Clinical and Experimental Obstetrics & Gynecology (CEOG) is published by IMR Press from Volume 47 Issue 1 (2020). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with S.O.G.
Caudal regression syndrome and sirenomelia in only one twin in two diabetic pregnancies
Many authors consider sirenomelia to be an extreme form of caudal regression syndrome (CRS), while others argue that they are two distinct entities. Maternal diabetes mellitus is considered to be an important predisposing factor for both CRS and sirenomelia. Two rare cases of diabetic, dizygotic twin pregnancies, each with one normal and one affected fetus are presented. In case I the affected fetus had CRS. In case 2 the affected fetus had sirenomelia. The present cases suggest that the pathogenesis of CRS and sirenomelia is more complex than previously thought, that maternal diabetes is not the only underlying pathogenetic mechanism and that genetic or epigenetic factors probably contribute to the formation of these conditions.