[Discordant fetal growth in multiple pregnancy: intervention should be based on chorionicity].

In three women, aged 28, 35, and 38 years, with multiple pregnancies and discordant foetal growth, the question arose what to do in case of (threatening) intrauterine death of one twin. In one monochorionic pregnancy with single foetal death the survivor suffered irreversible neurological damage and died at the age of five months, in one monochorionic pregnancy the survivor was born healthy and in one dichorionic pregnancy both twins were born healthy although one twin showed severe intrauterine growth retardation. The problem concerning single foetal death in a monochorionic pregnancy is whether to terminate the pregnancy and accept the risk of premature birth to the surviving twin, or to continue the pregnancy and accept the risk of damage to the survivor. In a dichorionic pregnancy foetal death of one twin does not entail any great risk of damage to the survivor; in such a pregnancy single foetal death in a premature phase may be accepted and the pregnancy may be continued. Sonographic determination of the chorionicity in multiple pregnancy at an early stage is essential because it also determines the policy if foetal problems occur.