We examine how increased Immigration and Customs Enforcement (ICE) activities impacted newborn health and prenatal care utilization in North Carolina around the time Section 287(g) of the Immigration and Nationality Act was first being implemented within the state. Focusing on administrative data between 2004 and 2006, we conduct difference-in-differences and triple-difference case-control regression analysis. Pregnancies were classified by levels of potential exposure to immigration enforcement depending on parental nativity and educational attainment. Contrast groups were foreign-born parents residing in nonadopting counties and all US-born non-Hispanic parents. The introduction of the program was estimated to decrease birth weight by 58.54 grams (95% confidence interval [CI], -83.52 to -33.54) with effects likely following from reduced intrauterine growth. These results are shown to coexist with a worsening in the timing of initiation and frequency of prenatal care received. Since birth outcomes influence health, education, and earnings trajectories, our findings suggest that the uptick in ICE activities can have large socioeconomic costs over US-born citizens.