Women in the U.S. are more likely to die from childbirth or pregnancy-related causes than other women in the developed world. About 700 women die each year in the U.S. as a result of pregnancy or delivery complications. Unlike other leading causes of death such as cancer or Alzheimer's disease, birth-related deaths are largely preventable. Today, however, most adverse pregnancy outcomes are not predictable and thus cannot be avoided, partly because of a lack of medical data. Using smartphones, the team will passively monitor the activity and behavior of 1,000 pregnant women in the Austin area. The ultimate goal is to develop digital phenotypes, or profiles, to better understand factors that influence pregnancy and can inform individualized pregnancy care.