IMPACT OF INTRODUCTION OF NIPT ON UPTAKE OF GENETIC TESTING IN FETUSES WITH CNS ANOMALIES

Abstract

Objectives To evaluate the impact of introduction of non-invasive prenatal testing (NIPT) on the uptake of invasive testing in pregnancies complicated by fetal central nervous system (CNS) anomalies. Methods Retrospective review of all singleton pregnancies complicated by fetal CNS anomalies seen at a single tertiary center 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: 308 (62%) were isolated CNS anomalies and 192 (38%) had additional structural anomalies. 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 prenatal investigations. The introduction of NIPT significantly decreased the number of pregnancies having no testing (44% Group A vs 22% in group B, p Conclusions Uptake of invasive prenatal testing in fetuses with brain anomalies was not affected by NIPT. However, the incidence of no genetic testing was significantly reduced. NIPT was a suboptimal testing strategy in this population as it missed a significant number of sub-chromosomal genetic anomalies.