Abstract/Project Summary: The Maternal Fetal Medicine Network is one of the première groups of clinical investigators in the country. The Columbia Center has been privileged to be a member of this research collaborative for over 19 years and is now submitting a limited competition continuation application to complete the current ongoing studies. The Columbia Center is composed of 5 large perinatal centers working together under a single administrative structure administered by Columbia University. The centers have a long and successful history of collaborative multi- centered research. During the last current cycle of the MFMU, the Columbia Center has ranked near the top in recruitment. Columbia Center faculty have designed and led major trials, performed ancillary studies and secondary analysis, served on subcommittees, and successfully presented concepts. Our faculty currently lead 4 of 9 ongoing MFMU protocols. The Columbia Center provides approximately 26,000 deliveries per year of which over 30% are high risk; has 43 MFM physicians, several of which have the protected time and expertise to be involved in Network activities; has tertiary level NICUs with neonatologists experienced in Network studies; well established infant follow-up programs; has a robust genetics program with 13 board certified clinical, cyto or molecular geneticists; and over 40 nurses, recruiters and staff dedicated to network activities.