Accuracy of reporting abortions with Down syndrome in England and Wales: a data linkage study.

Background The number of abortions of fetuses with Down syndrome in England and Wales reported by the Department of Health (DH) differs from that reported by the National Down Syndrome Cytogenetic Register (NDSCR). The aim of this study was to investigate the reasons for this. Methods Abortions in 2011 and 2012 from DH were matched to those from NDSCR. The number of cases not reported to either source was estimated. Results An estimated 2240 abortions of fetuses with Down syndrome occurred in 2011/12; NDSCR estimated 2208 and DH 1100. One thousand and six abortions were identified in both data sets, including 145 (14%) which were not recorded by DH as having Down syndrome. Abortions in NDSCR that were not matched in DH occurred throughout England and Wales and at all gestational ages. An estimated 61 abortions of fetuses with Down syndrome were not reported to DH or NDSCR. Conclusions The number of abortions of fetuses with Down syndrome reported by the NDSCR is more complete than that reported by the DH. DH data for abortions with other congenital anomalies are also likely to be underestimates, and more accurate estimates are available from BINOCAR regional congenital anomaly registers. [ABSTRACT FROM AUTHOR]