The assessment of the umbilical blood flow of the surviving twin after the intrauterine death of the other twin.

This paper summarizes our experience with Doppler velocimetry in survivors of intrauterine co-twin demise. In the first trimester, ten dichorionic deaths occurred; none of the survivors developed flow disorders. During the second trimester, there were three intrauterine demises, two of them were monochorionic and the survivors developed flow disorders: one presented transitory venous flow aberration, the other one an impaired development of diastolic flow. In the third trimester, two intrauterine deaths occurred. One case of twin to twin transfusion syndrome (TTTS) was complicated by the donor's death and the recipient showed a loss of diastolic flow. The second one happened during a dichorionic twin pregnancy. The survivor presented high systolic/diastolic daily ratio (S/D = 7.8).