In this multi-phase study, the authors intend to: i) undertake a needs assessment on the development of a mobile app for prenatal screening decisions, ii) develop a decision model using the process analytical hierarchy, and iii) develop an analytical app and evaluate its usefulness. This will provide pregnant women and their partners with easy access to up-to-date information on the risks and benefits of the various prenatal screening options, and help the prioritize what's most important to them about the various choices. Thus, they will be able to make an informed choice in line with their preferences and values. Read the protocol here.