Recently the March of Dimes and the International Federation of Gynecology and Obstetrics Working Group on Preterm Birth released its findings from an extensive cross-country individual patient data analysis of 4.1 million singleton births in five high-income, very high human development index countries. The specific contributions of 21 risk factors for both spontaneous and health care provider-initiated preterm birth were assessed to better understand how these vary among the countries selected for intensive study. We also wished to evaluate whether currently used clinical interventions to prevent preterm birth are associated with lower rates of preterm delivery. Individual and population-attributable preterm birth risks were determined and an assessment made to identify any contribution to cross-country differences. With this massive data set it was possible to assess the ability to predict preterm birth given various sets of known risk factors. It was also possible to estimate the potential effects of successful interventions to reduce preterm birth in relation to advances in the research, health care policy, and clinical practice sectors. In this article we summarize the seven most important findings from these analyses. Clearly there is a paucity of explicit and currently identifiable factors that are amenable to intervention with current clinical practice or changes in public health policy. Thus, we see an urgent and critically important need for research efforts to elucidate the underlying biological causes of spontaneous preterm birth. The need for new innovative and effective interventions to successfully pursue progress toward effective preterm birth reduction has never been more apparent.