Short Title: Pregnancy ResearchKit App 2 Background. Although maternal morbidity and mortality in the United States is among the worst of developed countries, pregnant women have been under-represented in research studies, resulting in deficiencies in evidence-based guidance for treatment. There are over two billion smartphone users worldwide, enabling researchers to easily and cheaply conduct extremely large-scale research studies through smartphone apps, especially among pregnant women in whom app use is exceptionally high, predominantly as an information conduit Objective: We aim to improve our understanding of factors that promote a healthy pregnancy for both the mother and developing fetus through the large-scale and simplified collection of participant-generated data.Study Design. We developed the first pregnancy research app that is embedded within an existing, popular pregnancy app for self-management and education of expectant mothers. Our research app is used to collect a combination of survey and sensor generated data from pregnant women living in the U.S.
Results. From the study's launch onMarch 16, 2017 through December 17, 2017, we have enrolled 2,058 participants from all 50 states. Our study population is diverse geographically and demographically, and fairly representative of U.S. population averages. We have collected 14,045 individual surveys and 11,669 days of sleep, activity, blood pressure and heart rate measurements during this time. On average, women stayed engaged in the study for 64 days and 48 percent who reached their due date filled out the final outcome survey. Conclusion. During the first nine months of the deployment of this unique program of ongoing research in pregnancy, we demonstrated the potential for a smartphone-based research platform to capture an ever-expanding array of longitudinal, objective and subjective participantgenerated data from a continuously growing and diverse population of pregnant women. Clinical Trials Registration: ClinicalTrials.gov Identifier: NCT03085875