Department or Program


Primary Wellesley Thesis Advisor

Professor Courtney Coile


Recent scientific advancements have greatly improved prenatal genetic testing technologies, which can now detect a wide array of genetic disorders at a high degree of accuracy. Down syndrome provides a unique context through which to analyze the effect of women’s access to prenatal genetic tests on test utilization and birth outcomes. In particular, typically only women of Advanced Maternal Age (AMA)—that is, women aged 35 and older—have qualified for an amniocentesis, the most common prenatal diagnostic test for Down syndrome. Using Vital Statistics live birth data from 1989 to 2002, I exploit the arbitrary nature of this AMA amniocentesis eligibility cutoff by implementing a Regression Discontinuity (RD) design to quantify the effect of access to amniocentesis on amniocentesis use and birth outcomes. As a secondary component of my analysis, I explore whether the effect of access to amniocentesis shifted over the course of the 1990s, as alternative prenatal genetic tests for Down syndrome became available. I find that becoming eligible for an amniocentesis increased the probability a woman underwent an amniocentesis by 6.2 percentage points (or 62% relative to the mean take-up rate of women around the cutoff), but that the increase in amniocentesis take-up at age 35 diminished significantly throughout the late 1990s. This negative time-trend in amniocentesis take-up at age 35 implies that over the latter half of my sample period, many amniocentesis-eligible women substituted away from amniocentesis and towards alternative prenatal genetic tests for Down syndrome that presented less risk to the fetus. Finally, I find no evidence that women terminated pregnancies that tested positive for Down syndrome or that test access affected other birth outcomes.