Vanishing twin due to an apparent gnomic imbalance

Abstract

The disappearance of one or more gestational rings on repeated ultrasonic examination during the 1 st trimester have led to the vanishing twin phenomenon. In recent years, the concept of vanishing twins has gained much attention during genetic amniocentesis. A couple was initially referred to us because of a high incidence of fetal loss. They later conceived with a twin pregnancy, however, one of the twins was lost at 7 weeks of gestation while the other one is a normal, 46,XX female. The couple experienced three more successive fetal losses and was referred for cytogenetic evaluation. Cytogenetic findings with GTG-and FISH- techniques revealed a balanced translation between chromosomes 9 and 11 in the father i.e. 46,XY,t(9;11)(p22;q22). ish 46,XY,t(9;11)(p22;q22)(wcp9+;wcp11+) while the mother is cytogenetically normal, 46XX. It is obvious that the vanished twin was cytogenetical abnormal with an unbalanced karyotype. The couple is religious and do not wish to go through an amniocentesis but want to have at least 10 more children. All options were explained to them. Their Rabbi suggested that they are only allowed a non-invasive procedure that must occur prior to five weeks of pregnancy. At present, the technology allowing enough maternal cells of fetal origin to be captured at such an early stage has not been perfected. The genetic and social aspects of vanishing twins is presented.