Brain-damaged survivors after intrauterine death of a monochorionic twin

Potential risks for a surviving twin after fetal death of a co-twin in twin-to-twin transfusion syndrome (TTTS) has been documented. Although some studies suggest ending a twin pregnancy after a single fetal death as soon as possible in order to minimize the risks of thromboembolic complications in the surviving twin, we are more concerned about the risks of a premature birth. In this study, we searched for a potential marker to predict thromboembolic complications in the surviving twin.

From 1993 to 1998, nine women in two teaching hospitals had pregnancies complicated by TTTS and the death of one fetus. In addition to routine ultrasound examinations and obstetric monitoring, all patients had disseminated intravascular coagulation tests. The outcome of the surviving fetus was recorded.

Three patients had silent and minimal coagulopathy (33%) that revealed only the presence of D-dimer. Among these three patients, two had a disappearance of serum D-dimer, but the other one had persistent D-dimer levels for more than 5 weeks and delivered a fetus with a cerebral infarction. Except for the above-mentioned fetus, all surviving fetuses were normal and healthy and were delivered at the median gestational age of 33 (range, 31-36) weeks. Of the nine surviving children, the mean interval between fetal death of one twin and delivery of the healthy twin was 22.7 days, ranging from 3 days to 47 days.

All patients having TTTS associated with one fetal death should be carefully monitored for coagulopathy; the appropriate time for delivery might depend on the duration of persistent D-dimer in the maternal blood. The long-term presence of D-dimer in the maternal serum may indicate a severe underlying thromboembolic complication in the surviving twin after intrauterine death of a monochorionic twin. Due to the increased risks of morbidity in premature births, the benefit of early termination of pregnancy in order to protect against subsequent sequelae in the surviving twin is minor and remains an area for future research.