"Vanishing Twin" had interested me ever since I was born as a twin. Vanishing Twin Syndrome was first recognise in 1945. This occurs when a twin or multiple disappears in the uterus during pregnancy as a result of  a miscarriage of one twin or multiple. The fetal tissue is absorbed by the other twin, multiple, placenta or the mother. This gives the appearance of a "Vanishing Twin." Before the use of ultrasound, the diagnosis of the death of a twin or multiple was made through an examination of the placenta after delivery. Today, with the availability of early ultrasounds, the presence of twins or multiple foetuses can be detected during the first trimester. A follow-up ultrasound may reveal the "disappearance" of a twin. It has been diagnosed more frequently since the use of ultrasonography in early pregnancy. 

​

One or two; consisting of two matching corresponding parts; to be linked for the purpose of exchanging or combining, either breaking or completely reabsorbed.