Photoacoustic imaging opens a new path to assess medical conditions where in vivo measurements are critical. Our aim is to study light delivery systems, the interaction of light with human placental tissue, and improve the depth resolution of photoacoustic imaging. Successful detection of placental hypoxia will allow us to noninvasively monitor the effect of placental ischemia during human pregnancy. The goal of this project is to develop methods to use photoacoustic imaging to monitor placental oxygenation in a clinical setting.