Introduction: Noninvasive prenatal testing (NIPT) can be used to detect fetal chromosomal abnormalities early in pregnancy. As eligibility criteria broaden and screening targets expand, gauging public acceptability of NIPT becomes increasingly important. Leveraging social media as a rich source of public discourse, the purpose of this study was to understand public opinions and attitudes toward NIPT on the social media platform Reddit. Methods: We applied content and natural language processing techniques (i.e., sentiment analysis) to textual data collected from 4 Reddit communities focusing on the NIPT content posted from September 2012 to September 2022 (367 posts and 7,822 comments in total). Results: Content analysis findings indicated that social media users consider NIPT to be worthwhile. Reasons NIPT was perceived to be not worthwhile related to unwanted anxiety, and the fact that NIPT results would not change anything about their approach to pregnancy were also expressed. The sentiment analysis identified more positive than negative emotions; the mean sentiment scores ranged from 0.48 to 1.22, depending on the specific Lexicon used. Specific emotions (i.e., trust, fear) were also identified. Conclusion: Our novel approach to understanding public perception and attitudes toward NIPT yielded results that are consistent with conventional patient-oriented research methods. These findings may not only contribute to ongoing improvements in prenatal patient care, research, and policy but also indicate that sentiment analysis applied to social media data can serve as a suitable means to assess public acceptability of NIPT, particularly as public dialogue on this topic increases over time.