Prenatal imaging and neurological follow-up in the survivors of monochorionic twin pregnancies with a single intrauterine death.

Objectives: To assess the outcome and neurological follow-up of the co-twins of monochorionic twin pregnancies with a single intrauterine death evaluated with prenatal ultrasound and magnetic resonance after the diagnosis of death. Methods: Thirteen monochorionic twin pregnancies with a single intrauterine demise were identified. Serial scans after the diagnosis of a single death were performed and, in addition, seven patients underwent prenatalMRI in order to identify the presence of cerebral lesions in the survivors. Postnatal cranial scans and results of neurological follow-up were recorded and analyzed in relation to the prenatal findings. Results: Median gestational age at the diagnosis of single fetal death was 24.3 (range, 17–32.2) weeks. Perinatal survival rate of the cotwin was 86% (11/13). MRI scans were performed at a median gestational age of 20.6 (range, 19.1–31.5) weeks. Mean latency between the diagnosis of single fetal death and the MRI scan was 15 ± 6.1 days. In all cases there were no signs of ischemic brain lesions in the survivors at the diagnosis of single death, during ultrasonographic follow-up or at MRI. One case was complicated by intrauterine death of the co-twin after 6 days (at 25 weeks) and in one case, delivered at 28 weeks for abnormal CTG immediately after the diagnosis of single death, IVH was evident at postnatal cranial scan, and the newborn died 3 days after birth. In both cases no sonographic signs of brain lesions were present and prenatal MRI was not performed. Cranial scans performed after birth did not show any abnormalities and no neurological sequelae were observed at the follow-up (mean time 17.5 ± 10.1 months) in any surviving infants. Conclusions: In monochorionic twin pregnancies ultrasound examination of the fetal brain of the twin survivor at the diagnosis of single intrauterine death can be normal, as it can also be in fetuses with successive evidence of cerebral lesions. Normal sonographic follow-up and prenatal MRI are associated with a good neurological prognosis.