OP16.09: Termination of pregnancy for central nervous system (CNS) anomalies

To evaluate the agreement between prenatal imaging (ultrasound/ MRI) and post termination of pregnancy (TOP) findings at pathological investigation (PI) or virtual necropsy (VN) in fetuses with central nervous system (CNS) anomalies. All TOP's with CNS involvement between 2006 and 2011 database were retrospectively analyzed. The level of agreement between prenatal findings and postnatal investigation for different groups of CMS malformations was analyzed. After exclusion of fetal chromosomal anomalies (n = 16) and cases without postmortem investigation (n = 15), 86 cases were included for analysis. In 35, 6, and 45 cases a PI, a VN or a combination of both postmortem investigations was performed respectively. Mean gestational age at termination was 24.0 ± 12.5 w. The final diagnosis remained unchanged in 79% when TOP was performed for major cerebral anomalies (76/86). Major and minor additional findings were present in 13.2% and 11.8% respectively. Full agreement was observed in 67.1%. When the primary indication for TOP was no CNS malformation (10/86), the non-agreement between prenatal and postnatal investigation for the cerebral anomaly was much higher (40%). For the main diagnosis a full agreement was observed in 6 cases (60.0%), and major additional findings in 3 (30.0%). NTD and destructive anomalies had both a high rate of full agreement (20/23 and 18/24 respectively). In proliferative disorders confirmation was present in 75.0% (6/8) and in midline anomalies only in 38.5% (5/13). For isolated ventriculomegaly, the agreement was low (33.3% (4/12)), the rate of major additional findings (50.0% (6/12)) was the highest of all groups, and it was most frequently caused by stenosis of the aqueduct (4/6). In 79% the final diagnosis in pregnancies terminated for a CNS-anomaly remained unchanged after postmortem investigation. Although major additional findings on postmortem examination were most relevant in the etiological work-up and counseling, these observations did not question the indication for TOP.