LAUSR

between 2010 and 2017. Cases who had undergone invasive testing or NIPT prior to the diagnosis of the CNS anomaly were excluded. Cases were segregated according to whether they were seen prior to introduction of NIPT (Group A, 2010-2013) or thereafter (Group B, 2014-2017). We examined the rate of invasive and non-invasive genetic testing in each group. RESULTS: We retrieved 500 cases of fetal CNS anomalies (Fig1). Overall, 308 (62%) cases were isolated and 192 (38%) had additional structural anomalies (‘complex’). In the total cohort, 165 women (33%) underwent expectant management with no further prenatal genetic testing, 166 (33%) had invasive testing, 52 (10%) had NIPT and 117 pregnancies (23%) were terminated without further genetic tests. In Group B, 21% underwent NIPT. The introduction of NIPT significantly decreased the number of pregnancies having no genetic testing (44% Group A vs 22% in group B, p<0.0001.) but did not change the uptake of invasive testing (34% vs 32% in group A and B, respectively; p1⁄40.61). In subgroup analysis, this decrease in patients choosing no testing was only significant in the subgroup of patients presenting with ventriculomegaly: where in group A 43 of 60 cases of fetal ventriculomegaly (72%) chose not to have any further testing, only 22 of 60 (37%) in group B chose not to have further testing in group B (p 1⁄40.0002). Of 47 low-risk NIPTs, 17 had follow-up with microarray, 3 of which showed pathogenic copy number variants (18%) (Table 1). CONCLUSION: Uptake of invasive prenatal testing in fetuses with brain anomalies was not affected by the introduction of NIPT. NIPT missed a significant number of CNVs.