It is difficult to imagine examples of greater physiological adaptations than those of the uteroplacental unit during pregnancy. The sheer scale of molecular, cellular and tissue remodeling, organogenesis, and organism development in a relatively short period of time seems the epitome of ‘‘systems biology.’’ The processes are challenging to comprehend, and investigate experimentally, but undoubtedly fascinating. Efforts to understand the physiology and pathology of these phenomena are of prime importance due to the considerable health and socioeconomic pressures brought to bear by the high incidences of compromised pregnancies and, especially, preterm birth (PTB). The World Health Organization-sponsored studies equate the worldwide incidence of PTB to be approximately 13 million births per year with approximately 1 million neonatal deaths attributable to PTB. If improved diagnosis and therapeutic treatment of PTB are to be achieved, an integrated understanding of the physiological basis of pregnancy and parturition is required. With this in mind, each year the Myometrium and Parturition Satellite Symposium of the Society for Gynecologic Investigation meeting gathers international experts in this field to share their experimental findings. We are delighted that several plenary speakers from the 2011 and 2012 symposia have provided reviews on their topics for this issue of Reproductive Sciences. The articles provide an up-to-date compendium that integrates many of the important facets of uteroplacental remodeling and function leading to term and preterm labor. Jerome Strauss (Virginia) introduces the importance of dynamic remodeling of the extracellular matrix (ECM) and its molecular components in uteroplacental tissues. With a focus on fetal membrane interfaces, he summarizes the ECMs’ multiplicity of roles including receptor signaling, cytokine/ growth factor sequestration, and tensile strength. Among the important molecular components are fetal fibronectin, hyaluronan, and up to 28 collagens, regulated by different metallomatrix proteinases. Mutations in many genes encoding such ECM proteins are associated with increased incidence of preterm premature rupture of membranes and the roles of environmental and/or epigenetic factors are being increasingly elucidated. In a similar vein, Shynlova et al (Toronto, Canada) describe pregnancy in terms of progressive changes of tissue remodeling under the control of localized inflammatory events (physiological inflammation). The authors posit a carefully structured theory whereby spatially restricted inflammatory events are under the influence of ever-changing endocrine (and a focus is given to the role of progesterone) and mechanical inputs activating a rich milieu of chemokine/cytokine signaling. These, in turn, serve to coordinate diverse processes such as decidualization, myometrial cell proliferation and growth, leukocyte migration, cervical remodeling, and postparturient involution. Olcese et al (Tallahassee, USA) review an oft-neglected consideration of the mechanisms responsible for the timing of parturition. They too give credence to the notion that pregnancy and parturition involve dynamic physiological adaptations—in this case that uterine contractions of labor may be initiated by activity of the central circadian oscillator of the maternal hypothalamic suprachiasmatic nuclei via the feedback ‘‘gating’’ actions of neuroendocrine outputs. Of key importance may well be circadian secretion of melatonin given recent interest in the uterotonic actions of this hormone and uterine expression of melatonin receptors. Regulation of contractile activity of the uterus is also the focus of reviews by Europe-Finner et al (Newcastle, UK) and Wim Lammers (Al Ain, UAE). The former concentrates on intracellular signaling and describes the possibility that posttranslational modification by acetylation may be a mechanism of wider significance to the uterus than first realized when considering ‘‘‘only’’ nuclear events of histone modification, chromatin remodeling, and gene transcription. They suggest