Incidence of Cerebral Injury in Monochorionic Twin Survivors after Spontaneous Single Demise: Long-Term Outcome of a Large Cohort

Objectives: To evaluate incidence of cerebral injury and outcome in a large series of monochorionic (MC) twin survivors after spontaneous single fetal demise. Methods: Retrospective analysis of all MC pregnancies with single fetal demise diagnosed at, or referred to, the Fetal Therapy Unit U. Nicolini, V. Buzzi Children's Hospital, Milan, Italy, from 2004 to 2015. Survivors evaluation protocol included detailed ultrasound (US) of intracranial anatomy, Doppler investigation of peak systolic velocity in the middle cerebral artery (MCA-PSV), and magnetic resonance (MR). Data were collected on pregnancy characteristics, postnatal brain scan, and MR and neurological follow-up. Results: Seventy-eight consecutive MC pregnancies were analyzed. Median gestational age (GA) at single fetal demise was 22 weeks (range 15-36); median interval between single demise and live birth was 105 days (range 1-175), with a median GA at birth of 36 weeks (range 23-41). Prenatal MR was performed in 57 of 78 cases (73%). Cerebral injury affected 14/78 (18%) co-twins, 2 of whom were born immediately after single demise, with postnatal diagnosis of cerebral injury; of the other 12 fetuses that were studied before birth, 10 had a prenatal diagnosis of lesion both with US and MR, one only with MR, and in one case, a grade III intraventricular hemorrhage was reported only after delivery, which occurred at 25 weeks, 5 weeks after the single demise. Signs of fetal anemia (MCA-PSV value above 1.55 MoM) were related to a higher risk of prenatal cerebral injury; cases with postnatal diagnosis of lesion were delivered at lower GA. Conclusions: Cerebral injury affects 18% of co-twin survivors after single fetal demise in MC twin pregnancies, and evaluation and follow-up of these cases can improve detection rate of such damage.