The interactions between the mother and the fetus during the progression of normal pregnancy involve trade-offs, or even conflicts, between factors that improve maternal health and those that support fetal development and growth. These may lead to selective evolutionary pressures that differ among species, and result in intriguing differences in reproductive strategies that enhance maternal-fetal biological harmony, and mitigate conflict. Intriguing strategies to balance these pressures include imprinting, coincident with placentation. Adverse pregnancy outcomes, such as miscarriage, preterm birth, preeclampsia and intrauterine growth restriction, are heterogeneous, and gaps remain in understanding how imbalances between maternal and fetal adaptations contribute to these disorders. The goal of this meeting is to bring together investigators from diverse disciplines who investigate maternal and fetal factors that shape pregnancy outcomes by exploring how these systems work together or are at odds. The conference will aim to develop these concepts, illuminating developmental, genomic/epigenomic, immune, microbial and metabolic factors as well as consider how acute exposures during pregnancy, such as infection, shape maternal-fetal outcomes. Understanding the biology underpinning these considerations will contribute to better diagnosis, treatment and disease prevention during pregnancy. The presentations will address critical gaps in our knowledge of maternal/fetal harmony and conflict, and target paths to improve understanding of issues related to social, economic and geographic inequality that predispose some groups to enhanced risk during pregnancy. A better understanding of the biology, and development of new collaborative possibilities and paths to improved clinical outcomes, are primary goals of the meeting.