Prenatal diagnosis of Down syndrome: a systematic review of termination rates (1995-2011).

Objective: The objective of this study was to review the published literature on pregnancy termination following a prenatal diagnosis of Down syndrome in the United States.

Method: A systematic search of US English-language articles (1995-2011) was conducted to identify primary research studies that reported data for pregnancies with definitive prenatal diagnosis of Down syndrome with subsequent pregnancy termination. Studies that provided indirect estimates of pregnancy termination, such as mathematical models, were excluded. The weighted mean termination rate was calculated across studies.

Results: Twenty-four studies were accepted. The weighted mean termination rate was 67% (range: 61%-93%) among seven population-based studies, 85% (range: 60%-90%) among nine hospital-based studies, and 50% (range: 0%-100%) among eight anomaly-based studies. Evidence suggests that termination rates have decreased in recent years. Termination rates also varied with maternal age, gestational age, and maternal race/ethnicity.

Conclusion: This systematic review presents the largest synthesis of United States data on termination rates following a prenatal diagnosis of Down syndrome. Evidence suggests that termination rates are lower than noted in a previous review that was based on less contemporary studies and had an international focus. Heterogeneity across studies suggests that a summary termination rate may not be applicable to the entire US population.